chore: update comments

.claude/CLAUDE.md

@@ -1,47 +0,0 @@
-To build Lean you should use `make -j -C build/release`.
-
-To run a test you should use `cd tests/lean/run && ./test_single.sh example_test.lean`.
-
-## New features
-
-When asked to implement new features:
-* begin by reviewing existing relevant code and tests
-* write comprehensive tests first (expecting that these will initially fail)
-* and then iterate on the implementation until the tests pass.
-
-All new tests should go in `tests/lean/run/`. These tests don't have expected output; we just check there are no errors. You should use `#guard_msgs` to check for specific messages.
-
-## Success Criteria
-
-*Never* report success on a task unless you have verified both a clean build without errors, and that the relevant tests pass.
-
-## Build System Safety
-
-**NEVER manually delete build directories** (build/, stage0/, stage1/, etc.) even when builds fail.
-- ONLY use the project's documented build command: `make -j -C build/release`
-- If a build is broken, ask the user before attempting any manual cleanup
-
-## LSP and IDE Diagnostics
-
-After rebuilding, LSP diagnostics may be stale until the user interacts with files. Trust command-line test results over IDE diagnostics.
-
-## Update prompting when the user is frustrated
-
-If the user expresses frustration with you, stop and ask them to help update this `.claude/CLAUDE.md` file with missing guidance.
-
-## Creating pull requests
-
-Follow the commit convention in `doc/dev/commit_convention.md`.
-
-**Title format:** `<type>: <subject>` where type is one of: `feat`, `fix`, `doc`, `style`, `refactor`, `test`, `chore`, `perf`.
-Subject should use imperative present tense ("add" not "added"), no capitalization, no trailing period.
-
-**Body format:** The first paragraph must start with "This PR". This paragraph is automatically incorporated into release notes. Use imperative present tense. Include motivation and contrast with previous behavior when relevant.
-
-Example:
-```
-feat: add optional binder limit to `mkPatternFromTheorem`
-
-This PR adds a `num?` parameter to `mkPatternFromTheorem` to control how many
-leading quantifiers are stripped when creating a pattern.
-```

.claude/commands/release.md

@@ -39,7 +39,6 @@ These comments explain the scripts' behavior, which repositories get special han
 
 ## Important Notes
 
-- **NEVER merge PRs autonomously** - always wait for the user to merge PRs themselves
 - The `release_steps.py` script is idempotent - it's safe to rerun
 - The `release_checklist.py` script is idempotent - it's safe to rerun
 - Some repositories depend on others (e.g., mathlib4 depends on batteries, aesop, etc.)

.gitattributes

@@ -4,7 +4,6 @@ RELEASES.md merge=union
 stage0/** binary linguist-generated
 # The following file is often manually edited, so do show it in diffs
 stage0/src/stdlib_flags.h -binary -linguist-generated
-doc/std/grove/GroveStdlib/Generated/** linguist-generated
 # These files should not have line endings translated on Windows, because
 # it throws off parser tests. Later lines override earlier ones, so the
 # runner code is still treated as ordinary text.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -9,7 +9,7 @@ assignees: ''
 
 ### Prerequisites
 
-<!-- Please put an X between the brackets as you perform the following steps: -->
+Please put an X between the brackets as you perform the following steps:
 
 * [ ] Check that your issue is not already filed:
       https://github.com/leanprover/lean4/issues

.github/workflows/actionlint.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v6
+      uses: actions/checkout@v5
     - name: actionlint
       uses: raven-actions/actionlint@v2
       with:

.github/workflows/build-template.yml

@@ -67,13 +67,13 @@ jobs:
         if: runner.os == 'macOS'
       - name: Checkout
         if: (!endsWith(matrix.os, '-with-cache'))
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           # the default is to use a virtual merge commit between the PR and master: just use the PR
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Namespace Checkout
         if: endsWith(matrix.os, '-with-cache')
-        uses: namespacelabs/nscloud-checkout-action@v8
+        uses: namespacelabs/nscloud-checkout-action@v7
         with:
           ref: ${{ github.event.pull_request.head.sha }}
       - name: Open Nix shell once
@@ -213,14 +213,14 @@ jobs:
           else
             ${{ matrix.tar || 'tar' }} cf - $dir | zstd -T0 --no-progress -o pack/$dir.tar.zst
           fi
-      - uses: actions/upload-artifact@v5
+      - uses: actions/upload-artifact@v4
         if: matrix.release
         with:
           name: build-${{ matrix.name }}
           path: pack/*
       - name: Lean stats
         run: |
-          build/$TARGET_STAGE/bin/lean --stats src/Lean.lean
+          build/$TARGET_STAGE/bin/lean --stats src/Lean.lean -Dexperimental.module=true
         if: ${{ !matrix.cross }}
       - name: Test
         id: test

.github/workflows/check-prelude.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           # the default is to use a virtual merge commit between the PR and master: just use the PR
           ref: ${{ github.event.pull_request.head.sha }}

.github/workflows/check-stage0.yml

@@ -8,7 +8,7 @@ jobs:
   check-stage0-on-queue:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v5
       with:
         ref: ${{ github.event.pull_request.head.sha }}
         fetch-depth: 0

.github/workflows/check-stdlib-flags.yml

@@ -1,57 +0,0 @@
-name: Check stdlib_flags.h modifications
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened, labeled, unlabeled]
-
-jobs:
-  check-stdlib-flags:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check if stdlib_flags.h was modified
-        uses: actions/github-script@v8
-        with:
-          script: |
-            // Get the list of files changed in this PR
-            const files = await github.paginate(
-              github.rest.pulls.listFiles,
-              {
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                pull_number: context.payload.pull_request.number,
-              }
-            );
-
-            // Check if stdlib_flags.h was modified
-            const stdlibFlagsModified = files.some(file =>
-              file.filename === 'src/stdlib_flags.h'
-            );
-
-            if (stdlibFlagsModified) {
-              console.log('src/stdlib_flags.h was modified in this PR');
-
-              // Check if the unlock label is present
-
-              const { data: pr } = await github.rest.pulls.get({
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                pull_number: context.issue.number,
-              });
-
-              const hasUnlockLabel = pr.labels.some(label =>
-                label.name === 'unlock-upstream-stdlib-flags'
-              );
-
-              if (!hasUnlockLabel) {
-                core.setFailed(
-                  'src/stdlib_flags.h was modified. This is likely a mistake. If you would like to change ' +
-                  'bootstrapping settings or request a stage0 update, you should modify stage0/src/stdlib_flags.h. ' +
-                  'If you really want to change src/stdlib_flags.h (which should be extremely rare), set the ' +
-                  'unlock-upstream-stdlib-flags label.'
-                );
-              } else {
-                console.log('Found unlock-upstream-stdlib-flags');
-              }
-            } else {
-              console.log('src/stdlib_flags.h was not modified');
-            }

.github/workflows/ci.yml

@@ -50,9 +50,9 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         # don't schedule nightlies on forks
-        if: github.event_name == 'schedule' && github.repository == 'leanprover/lean4' || inputs.action == 'release nightly' || (startsWith(github.ref, 'refs/tags/') && github.repository == 'leanprover/lean4')
+        if: github.event_name == 'schedule' && github.repository == 'leanprover/lean4' || inputs.action == 'release nightly'
       - name: Set Nightly
         if: github.event_name == 'schedule' && github.repository == 'leanprover/lean4' || inputs.action == 'release nightly'
         id: set-nightly
@@ -106,54 +106,9 @@ jobs:
           TAG_NAME="${GITHUB_REF##*/}"
           echo "RELEASE_TAG=$TAG_NAME" >> "$GITHUB_OUTPUT"
 
-      - name: Validate CMakeLists.txt version matches tag
-        if: steps.set-release.outputs.RELEASE_TAG != ''
-        run: |
-          echo "Validating CMakeLists.txt version matches tag ${{ steps.set-release.outputs.RELEASE_TAG }}"
-
-          # Extract version values from CMakeLists.txt
-          CMAKE_MAJOR=$(grep -E "^set\(LEAN_VERSION_MAJOR " src/CMakeLists.txt | grep -oE '[0-9]+')
-          CMAKE_MINOR=$(grep -E "^set\(LEAN_VERSION_MINOR " src/CMakeLists.txt | grep -oE '[0-9]+')
-          CMAKE_PATCH=$(grep -E "^set\(LEAN_VERSION_PATCH " src/CMakeLists.txt | grep -oE '[0-9]+')
-          CMAKE_IS_RELEASE=$(grep -m 1 -E "^set\(LEAN_VERSION_IS_RELEASE " src/CMakeLists.txt | grep -oE '[0-9]+')
-
-          # Expected values from tag parsing
-          TAG_MAJOR="${{ steps.set-release.outputs.LEAN_VERSION_MAJOR }}"
-          TAG_MINOR="${{ steps.set-release.outputs.LEAN_VERSION_MINOR }}"
-          TAG_PATCH="${{ steps.set-release.outputs.LEAN_VERSION_PATCH }}"
-
-          ERRORS=""
-
-          if [[ "$CMAKE_MAJOR" != "$TAG_MAJOR" ]]; then
-            ERRORS+="LEAN_VERSION_MAJOR: expected $TAG_MAJOR, found $CMAKE_MAJOR\n"
-          fi
-          if [[ "$CMAKE_MINOR" != "$TAG_MINOR" ]]; then
-            ERRORS+="LEAN_VERSION_MINOR: expected $TAG_MINOR, found $CMAKE_MINOR\n"
-          fi
-          if [[ "$CMAKE_PATCH" != "$TAG_PATCH" ]]; then
-            ERRORS+="LEAN_VERSION_PATCH: expected $TAG_PATCH, found $CMAKE_PATCH\n"
-          fi
-          if [[ "$CMAKE_IS_RELEASE" != "1" ]]; then
-            ERRORS+="LEAN_VERSION_IS_RELEASE: expected 1, found $CMAKE_IS_RELEASE\n"
-          fi
-
-          if [[ -n "$ERRORS" ]]; then
-            echo "::error::Version mismatch between tag and src/CMakeLists.txt"
-            echo ""
-            echo "Tag ${{ steps.set-release.outputs.RELEASE_TAG }} expects version $TAG_MAJOR.$TAG_MINOR.$TAG_PATCH"
-            echo "But src/CMakeLists.txt has mismatched values:"
-            echo -e "$ERRORS"
-            echo ""
-            echo "Fix src/CMakeLists.txt, delete the tag, and re-tag."
-            exit 1
-          fi
-
-          echo "Version validation passed: $TAG_MAJOR.$TAG_MINOR.$TAG_PATCH"
-
       # 0: PRs without special label
       # 1: PRs with `merge-ci` label, merge queue checks, master commits
-      # 2: nightlies
-      # 3: PRs with `release-ci` label, full releases
+      # 2: PRs with `release-ci` label, releases (incl. nightlies)
       - name: Set check level
         id: set-level
         # We do not use github.event.pull_request.labels.*.name here because
@@ -163,16 +118,14 @@ jobs:
           check_level=0
           fast=false
 
-          if [[ -n "${{ steps.set-release.outputs.RELEASE_TAG }}" || -n "${{ steps.set-release-custom.outputs.RELEASE_TAG }}" ]]; then
-            check_level=3
-          elif [[ -n "${{ steps.set-nightly.outputs.nightly }}" ]]; then
+          if [[ -n "${{ steps.set-nightly.outputs.nightly }}" || -n "${{ steps.set-release.outputs.RELEASE_TAG }}" || -n "${{ steps.set-release-custom.outputs.RELEASE_TAG }}" ]]; then
             check_level=2
           elif [[ "${{ github.event_name }}" != "pull_request" ]]; then
             check_level=1
           else
             labels="$(gh api repos/${{ github.repository_owner }}/${{ github.event.repository.name }}/pulls/${{ github.event.pull_request.number }} --jq '.labels')"
             if echo "$labels" | grep -q "release-ci"; then
-              check_level=3
+              check_level=2
             elif echo "$labels" | grep -q "merge-ci"; then
               check_level=1
             fi
@@ -247,8 +200,8 @@ jobs:
                 "test": true,
                 // NOTE: `test-speedcenter` currently seems to be broken on `ubuntu-latest`
                 "test-speedcenter": large && level >= 2,
-                // We are not warning-free yet on all platforms, start here
-                "CMAKE_OPTIONS": "-DLEAN_EXTRA_CXX_FLAGS=-Werror",
+                // made explicit until it can be assumed to have propagated to PRs
+                "CMAKE_OPTIONS": "-DUSE_LAKE=ON",
               },
               {
                 "name": "Linux Reldebug",
@@ -257,25 +210,17 @@ jobs:
                 "test": true,
                 "CMAKE_PRESET": "reldebug",
               },
-              {
+              // TODO: suddenly started failing in CI
+              /*{
                 "name": "Linux fsanitize",
-                // Always run on large if available, more reliable regarding timeouts
-                "os": large ? "nscloud-ubuntu-22.04-amd64-8x16-with-cache" : "ubuntu-latest",
+                "os": "ubuntu-latest",
                 "enabled": level >= 2,
-                // do not fail nightlies on this for now
-                "secondary": level <= 2,
                 "test": true,
                 // turn off custom allocator & symbolic functions to make LSAN do its magic
                 "CMAKE_PRESET": "sanitize",
-                // `StackOverflow*` correctly triggers ubsan.
-                // `reverse-ffi` fails to link in sanitizers.
-                // `interactive` and `async_select_channel` fail nondeterministically, would need to
-                // be investigated..
-                // 9366 is too close to timeout.
-                // `bv_` sometimes times out calling into cadical even though we should be using the
-                // standard compile flags for it.
-                "CTEST_OPTIONS": "-E 'StackOverflow|reverse-ffi|interactive|async_select_channel|9366|run/bv_'"
-              },
+                // exclude seriously slow/problematic tests (laketests crash)
+                "CTEST_OPTIONS": "-E 'interactivetest|leanpkgtest|laketest|benchtest'"
+              },*/
               {
                 "name": "macOS",
                 "os": "macos-15-intel",
@@ -307,7 +252,7 @@ jobs:
               },
               {
                 "name": "Windows",
-                "os": large && (fast || level >= 2) ? "namespace-profile-windows-amd64-4x16" : "windows-2022",
+                "os": large && (fast || level == 2) ? "namespace-profile-windows-amd64-4x16" : "windows-2022",
                 "release": true,
                 "enabled": level >= 2,
                 "test": true,
@@ -430,11 +375,11 @@ jobs:
     runs-on: ubuntu-latest
     needs: build
     steps:
-      - uses: actions/download-artifact@v6
+      - uses: actions/download-artifact@v5
         with:
           path: artifacts
       - name: Release
-        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836
         with:
           files: artifacts/*/*
           fail_on_unmatched_files: true
@@ -455,14 +400,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           # needed for tagging
           fetch-depth: 0
           # Doesn't seem to be working when additionally fetching from lean4-nightly
           #filter: tree:0
           token: ${{ secrets.PUSH_NIGHTLY_TOKEN }}
-      - uses: actions/download-artifact@v6
+      - uses: actions/download-artifact@v5
         with:
           path: artifacts
       - name: Prepare Nightly Release
@@ -480,7 +425,7 @@ jobs:
           echo -e "\n*Full commit log*\n" >> diff.md
           git log --oneline "$last_tag"..HEAD | sed 's/^/* /' >> diff.md
       - name: Release Nightly
-        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836
         with:
           body_path: diff.md
           prerelease: true

.github/workflows/copyright-header.yml

@@ -6,7 +6,7 @@ jobs:
   check-lean-files:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v5
 
     - name: Verify .lean files start with a copyright header.
       run: |

.github/workflows/grove.yml

@@ -51,7 +51,7 @@ jobs:
       - name: Fetch upstream invalidated facts
         if: ${{ steps.should-run.outputs.should-run == 'true' && steps.workflow-info.outputs.pullRequestNumber != '' }}
         id: fetch-upstream
-        uses: TwoFx/grove-action/fetch-upstream@v0.5
+        uses: TwoFx/grove-action/fetch-upstream@v0.4
         with:
           artifact-name: grove-invalidated-facts
           base-ref: master
@@ -65,7 +65,6 @@ jobs:
           workflow: ci.yml
           path: artifacts
           name: "build-Linux release"
-          allow_forks: true
           name_is_regexp: true
 
       - name: Unpack toolchain
@@ -96,7 +95,7 @@ jobs:
       - name: Build
         if: ${{ steps.should-run.outputs.should-run == 'true' }}
         id: build
-        uses: TwoFx/grove-action/build@v0.5
+        uses: TwoFx/grove-action/build@v0.4
         with:
           project-path: doc/std/grove
           script-name: grove-stdlib

.github/workflows/pr-release.yml

@@ -71,7 +71,7 @@ jobs:
           GH_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
       - name: Release (short format)
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836
         with:
           name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }}
           # There are coredumps files here as well, but all in deeper subdirectories.
@@ -86,7 +86,7 @@ jobs:
 
       - name: Release (SHA-suffixed format)
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b
+        uses: softprops/action-gh-release@6cbd405e2c4e67a21c47fa9e383d020e4e28b836
         with:
           name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }} (${{ steps.workflow-info.outputs.sourceHeadSha }})
           # There are coredumps files here as well, but all in deeper subdirectories.
@@ -127,7 +127,7 @@ jobs:
               description: "${{ github.repository_owner }}/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}",
             });
 
-      - name: Add toolchain-available label
+      - name: Add label
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         uses: actions/github-script@v8
         with:
@@ -166,14 +166,22 @@ jobs:
           if [ "$NIGHTLY_SHA" = "$MERGE_BASE_SHA" ]; then
             echo "The merge base of this PR coincides with the nightly release"
 
+            BATTERIES_REMOTE_TAGS="$(git ls-remote https://github.com/leanprover-community/batteries.git nightly-testing-"$MOST_RECENT_NIGHTLY")"
             MATHLIB_REMOTE_TAGS="$(git ls-remote https://github.com/leanprover-community/mathlib4-nightly-testing.git nightly-testing-"$MOST_RECENT_NIGHTLY")"
 
-            if [[ -n "$MATHLIB_REMOTE_TAGS" ]]; then
-              echo "... and Mathlib has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
+            if [[ -n "$BATTERIES_REMOTE_TAGS" ]]; then
+              echo "... and Batteries has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
               MESSAGE=""
+
+              if [[ -n "$MATHLIB_REMOTE_TAGS" ]]; then
+                echo "... and Mathlib has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
+              else
+                echo "... but Mathlib does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
+                MESSAGE="- ❗ Mathlib CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Mathlib CI should run now."
+              fi
             else
-              echo "... but Mathlib does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
-              MESSAGE="- ❗ Mathlib CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Mathlib CI should run now."
+              echo "... but Batteries does not yet have a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
+              MESSAGE="- ❗ Batteries CI can not be attempted yet, as the \`nightly-testing-$MOST_RECENT_NIGHTLY\` tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto \`nightly-with-mathlib\`, Batteries CI should run now."
             fi
           else
             echo "The most recently nightly tag on this branch has SHA: $NIGHTLY_SHA"
@@ -387,7 +395,7 @@ jobs:
       # Checkout the Batteries repository with all branches
       - name: Checkout Batteries repository
         if: steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true'
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           repository: leanprover-community/batteries
           token: ${{ secrets.MATHLIB4_BOT }}
@@ -418,7 +426,7 @@ jobs:
             git switch -c lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }} "$BASE"
             echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
-            git commit --allow-empty -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           else
             echo "Branch already exists, updating lean-toolchain."
             git switch lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
@@ -427,7 +435,7 @@ jobs:
             git merge "$BASE" --strategy-option ours --no-commit --allow-unrelated-histories
             echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
-            git commit --allow-empty -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 
       - name: Push changes
@@ -447,7 +455,7 @@ jobs:
       # Checkout the mathlib4 repository with all branches
       - name: Checkout mathlib4 repository
         if: steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true'
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           repository: leanprover-community/mathlib4-nightly-testing
           token: ${{ secrets.MATHLIB4_BOT }}
@@ -488,7 +496,7 @@ jobs:
             sed -i 's,require "leanprover-community" / "batteries" @ git ".\+",require "leanprover-community" / "batteries" @ git "lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}",' lakefile.lean
             lake update batteries
             git add lakefile.lean lake-manifest.json
-            git commit --allow-empty -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           else
             echo "Branch already exists, updating lean-toolchain and bumping Batteries."
             git switch lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
@@ -499,7 +507,7 @@ jobs:
             git add lean-toolchain
             lake update batteries
             git add lake-manifest.json
-            git commit --allow-empty -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 
       - name: Push changes
@@ -507,18 +515,6 @@ jobs:
         run: |
           git push origin lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
 
-      - name: Add mathlib4-nightly-available label
-        if: steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true'
-        uses: actions/github-script@v8
-        with:
-          script: |
-            await github.rest.issues.addLabels({
-              issue_number: ${{ steps.workflow-info.outputs.pullRequestNumber }},
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              labels: ['mathlib4-nightly-available']
-            })
-
       # We next automatically create a reference manual branch using this toolchain.
       # Reference manual CI will be responsible for reporting back success or failure
       # to the PR comments asynchronously (and thus transitively SubVerso/Verso).
@@ -530,7 +526,7 @@ jobs:
       # Checkout the reference manual repository with all branches
       - name: Checkout mathlib4 repository
         if: steps.workflow-info.outputs.pullRequestNumber != '' && steps.reference-manual-ready.outputs.manual_ready == 'true'
-        uses: actions/checkout@v6
+        uses: actions/checkout@v5
         with:
           repository: leanprover/reference-manual
           token: ${{ secrets.MANUAL_PR_BOT }}
@@ -562,7 +558,7 @@ jobs:
             echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
             git add lakefile.lean lake-manifest.json
-            git commit --allow-empty -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           else
             echo "Branch already exists, updating lean-toolchain."
             git switch lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
@@ -572,7 +568,7 @@ jobs:
             echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
             git add lake-manifest.json
-            git commit --allow-empty -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 
       - name: Push changes

.github/workflows/pr-title.yml

@@ -15,6 +15,6 @@ jobs:
           script: |
             const msg = context.payload.pull_request? context.payload.pull_request.title : context.payload.merge_group.head_commit.message;
             console.log(`Message: ${msg}`)
-            if (!/^(feat|fix|doc|style|refactor|test|chore|perf): (?![A-Z][a-z]).*[^.]($|\n\n)/.test(msg)) {
+            if (!/^(feat|fix|doc|style|refactor|test|chore|perf): .*[^.]($|\n\n)/.test(msg)) {
               core.setFailed('PR title does not follow the Commit Convention (https://leanprover.github.io/lean4/doc/dev/commit_convention.html).');
             }

.github/workflows/update-stage0.yml

@@ -27,7 +27,7 @@ jobs:
     # This action should push to an otherwise protected branch, so it
     # uses a deploy key with write permissions, as suggested at
     # https://stackoverflow.com/a/76135647/946226
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v5
       with:
         ssh-key: ${{secrets.STAGE0_SSH_KEY}}
     - run: echo "should_update_stage0=yes" >> "$GITHUB_ENV"

CMakeLists.txt

@@ -44,9 +44,7 @@ if (NOT ${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
     set(CADICAL_CXX c++)
     if (CADICAL_USE_CUSTOM_CXX)
       set(CADICAL_CXX ${CMAKE_CXX_COMPILER})
-      # Use same platform flags as for Lean executables, in particular from `prepare-llvm-linux.sh`,
-      # but not Lean-specific `LEAN_EXTRA_CXX_FLAGS` such as fsanitize.
-      set(CADICAL_CXXFLAGS "${CMAKE_CXX_FLAGS}")
+      set(CADICAL_CXXFLAGS "${LEAN_EXTRA_CXX_FLAGS}")
       set(CADICAL_LDFLAGS "-Wl,-rpath=\\$$ORIGIN/../lib")
     endif()
     find_program(CCACHE ccache)

CMakePresets.json

@@ -41,7 +41,7 @@
         "SMALL_ALLOCATOR": "OFF",
         "USE_MIMALLOC": "OFF",
         "BSYMBOLIC": "OFF",
-        "LEAN_TEST_VARS": "MAIN_STACK_SIZE=16000 LSAN_OPTIONS=max_leaks=10"
+        "LEAN_TEST_VARS": "MAIN_STACK_SIZE=16000"
       },
       "generator": "Unix Makefiles",
       "binaryDir": "${sourceDir}/build/sanitize"

doc/dev/bootstrap.md

@@ -72,9 +72,6 @@ update the archived C source code of the stage 0 compiler in `stage0/src`.
 
 The github repository will automatically update stage0 on `master` once
 `src/stdlib_flags.h` and `stage0/src/stdlib_flags.h` are out of sync.
-To trigger this, modify `stage0/src/stdlib_flags.h` (e.g., by adding or changing
-a comment). When `update-stage0` runs, it will overwrite `stage0/src/stdlib_flags.h`
-with the contents of `src/stdlib_flags.h`, bringing them back in sync.
 
 NOTE: A full rebuild of stage 1 will only be triggered when the *committed* contents of `stage0/` are changed.
 Thus if you change files in it manually instead of through `update-stage0-commit` (see below) or fetching updates from git, you either need to commit those changes first or run `make -C build/release clean-stdlib`.

doc/dev/ffi.md

@@ -1,9 +1,190 @@
 # Foreign Function Interface
 
-The Lean FFI documentation is now part of the [Lean language reference](https://lean-lang.org/doc/reference/latest/).
+NOTE: The current interface was designed for internal use in Lean and should be considered **unstable**.
+It will be refined and extended in the future.
 
- * [General FFI](https://lean-lang.org/doc/reference/latest/find/?domain=Verso.Genre.Manual.section&name=ffi)
- * [Representation of inductive types](https://lean-lang.org/doc/reference/latest/find/?domain=Verso.Genre.Manual.section&name=inductive-types-ffi)
- * [String](https://lean-lang.org/doc/reference/latest/find/?domain=Verso.Genre.Manual.section&name=string-ffi)
- * [Array](https://lean-lang.org/doc/reference/latest/find/?domain=Verso.Genre.Manual.section&name=array-ffi)
+As Lean is written partially in Lean itself and partially in C++, it offers efficient interoperability between the two languages (or rather, between Lean and any language supporting C interfaces).
+This support is however currently limited to transferring Lean data types; in particular, it is not possible yet to pass or return compound data structures such as C `struct`s by value from or to Lean.
 
+There are two primary attributes for interoperating with other languages:
+* `@[extern "sym"] constant leanSym : ...` binds a Lean declaration to the external symbol `sym`.
+  It can also be used with `def` to provide an internal definition, but ensuring consistency of both definitions is up to the user.
+* `@[export sym] def leanSym : ...` exports `leanSym` under the unmangled symbol name `sym`.
+
+For simple examples of how to call foreign code from Lean and vice versa, see <https://github.com/leanprover/lean4/blob/master/src/lake/examples/ffi> and <https://github.com/leanprover/lean4/blob/master/src/lake/examples/reverse-ffi>, respectively.
+
+## The Lean ABI
+
+The Lean Application Binary Interface (ABI) describes how the signature of a Lean declaration is encoded as a native calling convention.
+It is based on the standard C ABI and calling convention of the target platform.
+For a Lean declaration marked with either `@[extern "sym"]` or `@[export sym]` for some symbol name `sym`, let `α₁ → ... → αₙ → β` be the normalized declaration's type.
+If `n` is 0, the corresponding C declaration is
+```c
+extern s sym;
+```
+where `s` is the C translation of `β` as specified in the next section.
+In the case of an `@[extern]` definition, the symbol's value is guaranteed to be initialized only after calling the Lean module's initializer or that of an importing module; see [Initialization](#initialization).
+
+If `n` is greater than 0, the corresponding C declaration is
+```c
+s sym(t₁, ..., tₘ);
+```
+where the parameter types `tᵢ` are the C translation of the `αᵢ` as in the next section.
+In the case of `@[extern]` all *irrelevant* types are removed first; see next section.
+
+### Translating Types from Lean to C
+
+* The integer types `UInt8`, ..., `UInt64`, `USize` are represented by the C types `uint8_t`, ..., `uint64_t`, `size_t`, respectively
+* `Char` is represented by `uint32_t`
+* `Float` is represented by `double`
+* An *enum* inductive type of at least 2 and at most 2^32 constructors, each of which with no parameters, is represented by the first type of `uint8_t`, `uint16_t`, `uint32_t` that is sufficient to represent all constructor indices.
+
+  For example, the type `Bool` is represented as `uint8_t` with values `0` for `false` and `1` for `true`.
+* `Decidable α` is represented the same way as `Bool`
+* An inductive type with a *trivial structure*, that is,
+  * it is none of the types described above
+  * it is not marked `unsafe`
+  * it has a single constructor with a single parameter of *relevant* type
+
+  is represented by the representation of that parameter's type.
+
+  For example, `{ x : α // p }`, the `Subtype` structure of a value of type `α` and an irrelevant proof, is represented by the representation of `α`.
+  Similarly, the signed integer types `Int8`, ..., `Int64`, `ISize` are also represented by the unsigned C types `uint8_t`, ..., `uint64_t`, `size_t`, respectively, because they have a trivial structure.
+* `Nat` and `Int` are represented by `lean_object *`.
+  Their runtime values is either a pointer to an opaque bignum object or, if the lowest bit of the "pointer" is 1 (`lean_is_scalar`), an encoded unboxed natural number or integer (`lean_box`/`lean_unbox`).
+* A universe `Sort u`, type constructor `... → Sort u`, `Void α` or proposition `p : Prop` is *irrelevant* and is either statically erased (see above) or represented as a `lean_object *` with the runtime value `lean_box(0)`
+* Any other type is represented by `lean_object *`.
+  Its runtime value is a pointer to an object of a subtype of `lean_object` (see the "Inductive types" section below) or the unboxed value `lean_box(cidx)` for the `cidx`th constructor of an inductive type if this constructor does not have any relevant parameters.
+
+  Example: the runtime value of `u : Unit` is always `lean_box(0)`.
+
+#### Inductive types
+
+For inductive types which are in the fallback `lean_object *` case above and not trivial constructors, the type is stored as a `lean_ctor_object`, and `lean_is_ctor` will return true. A `lean_ctor_object` stores the constructor index in the header, and the fields are stored in the `m_objs` portion of the object.
+
+The memory order of the fields is derived from the types and order of the fields in the declaration. They are ordered as follows:
+
+* Non-scalar fields stored as `lean_object *`
+* Fields of type `USize`
+* Other scalar fields, in decreasing order by size
+
+Within each group the fields are ordered in declaration order. Trivial wrapper types count as their underlying wrapped type for this purpose.
+
+* To access fields of the first kind, use `lean_ctor_get(val, i)` to get the `i`th non-scalar field.
+* To access `USize` fields, use `lean_ctor_get_usize(val, n+i)` to get the `i`th usize field and `n` is the total number of fields of the first kind.
+* To access other scalar fields, use `lean_ctor_get_uintN(val, off)` or `lean_ctor_get_usize(val, off)` as appropriate. Here `off` is the byte offset of the field in the structure, starting at `n*sizeof(void*)` where `n` is the number of fields of the first two kinds.
+
+For example, a structure such as
+```lean
+structure S where
+  ptr_1 : Array Nat
+  usize_1 : USize
+  sc64_1 : UInt64
+  sc64_2 : { x : UInt64 // x > 0 } -- wrappers of scalars count as scalars
+  sc64_3 : Float -- `Float` is 64 bit
+  sc8_1 : Bool
+  sc16_1 : UInt16
+  sc8_2 : UInt8
+  sc64_4 : UInt64
+  usize_2 : USize
+  sc32_1 : Char -- trivial wrapper around `UInt32`
+  sc32_2 : UInt32
+  sc16_2 : UInt16
+```
+would get re-sorted into the following memory order:
+
+* `S.ptr_1` - `lean_ctor_get(val, 0)`
+* `S.usize_1` - `lean_ctor_get_usize(val, 1)`
+* `S.usize_2` - `lean_ctor_get_usize(val, 2)`
+* `S.sc64_1` - `lean_ctor_get_uint64(val, sizeof(void*)*3)`
+* `S.sc64_2` - `lean_ctor_get_uint64(val, sizeof(void*)*3 + 8)`
+* `S.sc64_3` - `lean_ctor_get_float(val, sizeof(void*)*3 + 16)`
+* `S.sc64_4` - `lean_ctor_get_uint64(val, sizeof(void*)*3 + 24)`
+* `S.sc32_1` - `lean_ctor_get_uint32(val, sizeof(void*)*3 + 32)`
+* `S.sc32_2` - `lean_ctor_get_uint32(val, sizeof(void*)*3 + 36)`
+* `S.sc16_1` - `lean_ctor_get_uint16(val, sizeof(void*)*3 + 40)`
+* `S.sc16_2` - `lean_ctor_get_uint16(val, sizeof(void*)*3 + 42)`
+* `S.sc8_1` - `lean_ctor_get_uint8(val, sizeof(void*)*3 + 44)`
+* `S.sc8_2` - `lean_ctor_get_uint8(val, sizeof(void*)*3 + 45)`
+
+### Borrowing
+
+By default, all `lean_object *` parameters of an `@[extern]` function are considered *owned*, i.e. the external code is passed a "virtual RC token" and is responsible for passing this token along to another consuming function (exactly once) or freeing it via `lean_dec`.
+To reduce reference counting overhead, parameters can be marked as *borrowed* by prefixing their type with `@&`.
+Borrowed objects must only be passed to other non-consuming functions (arbitrarily often) or converted to owned values using `lean_inc`.
+In `lean.h`, the `lean_object *` aliases `lean_obj_arg` and `b_lean_obj_arg` are used to mark this difference on the C side.
+
+Return values and `@[export]` parameters are always owned at the moment.
+
+## Initialization
+
+When including Lean code as part of a larger program, modules must be *initialized* before accessing any of their declarations.
+Module initialization entails
+* initialization of all "constants" (nullary functions), including closed terms lifted out of other functions
+* execution of all `[init]` functions
+* execution of all `[builtin_init]` functions, if the `builtin` parameter of the module initializer has been set
+
+The module initializer is automatically run with the `builtin` flag for executables compiled from Lean code and for "plugins" loaded with `lean --plugin`.
+For all other modules imported by `lean`, the initializer is run without `builtin`.
+Thus `[init]` functions are run iff their module is imported, regardless of whether they have native code available or not, while `[builtin_init]` functions are only run for native executable or plugins, regardless of whether their module is imported or not.
+`lean` uses built-in initializers for e.g. registering basic parsers that should be available even without importing their module (which is necessary for bootstrapping).
+
+The initializer for module `A.B` is called `initialize_A_B` and will automatically initialize any imported modules.
+Module initializers are idempotent (when run with the same `builtin` flag), but not thread-safe.
+
+**Important for process-related functionality**: If your application needs to use process-related functions from libuv, such as `Std.Internal.IO.Process.getProcessTitle` and `Std.Internal.IO.Process.setProcessTitle`, you must call `lean_setup_args(argc, argv)` (which returns a potentially modified `argv` that must be used in place of the original) **before** calling `lean_initialize()` or `lean_initialize_runtime_module()`. This sets up process handling capabilities correctly, which is essential for certain system-level operations that Lean's runtime may depend on.
+
+Together with initialization of the Lean runtime, you should execute code like the following exactly once before accessing any Lean declarations:
+
+```c
+void lean_initialize_runtime_module();
+void lean_initialize();
+char ** lean_setup_args(int argc, char ** argv);
+
+lean_object * initialize_A_B(uint8_t builtin);
+lean_object * initialize_C(uint8_t builtin);
+...
+
+argv = lean_setup_args(argc, argv); // if using process-related functionality
+lean_initialize_runtime_module();
+//lean_initialize();  // necessary (and replaces `lean_initialize_runtime_module`) if you (indirectly) access the `Lean` package
+
+lean_object * res;
+// use same default as for Lean executables
+uint8_t builtin = 1;
+res = initialize_A_B(builtin);
+if (lean_io_result_is_ok(res)) {
+    lean_dec_ref(res);
+} else {
+    lean_io_result_show_error(res);
+    lean_dec(res);
+    return ...;  // do not access Lean declarations if initialization failed
+}
+res = initialize_C(builtin);
+if (lean_io_result_is_ok(res)) {
+...
+
+//lean_init_task_manager();  // necessary if you (indirectly) use `Task`
+lean_io_mark_end_initialization();
+```
+
+In addition, any other thread not spawned by the Lean runtime itself must be initialized for Lean use by calling
+```c
+void lean_initialize_thread();
+```
+and should be finalized in order to free all thread-local resources by calling
+```c
+void lean_finalize_thread();
+```
+
+## `@[extern]` in the Interpreter
+
+The interpreter can run Lean declarations for which symbols are available in loaded shared libraries, which includes `@[extern]` declarations.
+Thus to e.g. run `#eval` on such a declaration, you need to
+1. compile (at least) the module containing the declaration and its dependencies into a shared library, and then
+1. pass this library to `lean --load-dynlib=` to run code `import`ing this module.
+
+Note that it is not sufficient to load the foreign library containing the external symbol because the interpreter depends on code that is emitted for each `@[extern]` declaration.
+Thus it is not possible to interpret an `@[extern]` declaration in the same file.
+
+See [`tests/compiler/foreign`](https://github.com/leanprover/lean4/tree/master/tests/compiler/foreign/) for an example.

doc/dev/release_checklist.md

@@ -69,10 +69,6 @@ We'll use `v4.6.0` as the intended release version as a running example.
     - `repl`:
       There are two copies of `lean-toolchain`/`lakefile.lean`:
       in the root, and in `test/Mathlib/`. Edit both, and run `lake update` in both directories.
-    - `lean-fro.org`:
-      After updating the toolchains and running `lake update`, you must run `scripts/update.sh` to regenerate
-      the site content. This script updates generated files that depend on the Lean version.
-      The `release_steps.py` script handles this automatically.
 - An awkward situation that sometimes occurs (e.g. with Verso) is that the `master`/`main` branch has already been moved
   to a nightly toolchain that comes *after* the stable toolchain we are
   targeting. In this case it is necessary to create a branch `releases/v4.6.0` from the last commit which was on

doc/dev/testing.md

@@ -51,10 +51,6 @@ All these tests are included by [src/shell/CMakeLists.txt](https://github.com/le
   codes and do not check the expected output even though output is
   produced, it is ignored.
 
-  **Note:** Tests in this directory run with `-Dlinter.all=false` to reduce noise.
-  If your test needs to verify linter behavior (e.g., deprecation warnings),
-  explicitly enable the relevant linter with `set_option linter.<name> true`.
-
 - [`tests/lean/interactive`](https://github.com/leanprover/lean4/tree/master/tests/lean/interactive/): are designed to test server requests at a
   given position in the input file. Each .lean file contains comments
   that indicate how to simulate a client request at that position.

doc/examples/palindromes.lean

@@ -94,8 +94,10 @@ theorem List.palindrome_of_eq_reverse (h : as.reverse = as) : Palindrome as := b
   next   => exact Palindrome.nil
   next a => exact Palindrome.single a
   next a b as ih =>
-    obtain ⟨rfl, h, -⟩ := by simpa using h
-    exact Palindrome.sandwich b (ih h)
+    have : a = b := by simp_all
+    subst this
+    have : as.reverse = as := by simp_all
+    exact Palindrome.sandwich a (ih this)
 
 /-!
 We now define a function that returns `true` iff `as` is a palindrome.

doc/std/grove/GroveStdlib/Generated.lean

@@ -4,7 +4,6 @@ import GroveStdlib.Generated.«associative-creation-operations»
 import GroveStdlib.Generated.«associative-modification-operations»
 import GroveStdlib.Generated.«associative-create-then-query»
 import GroveStdlib.Generated.«associative-all-operations-covered»
-import GroveStdlib.Generated.«slice-producing»
 
 /-
 This file is autogenerated by grove. You can manually edit it, for example to resolve merge
@@ -21,4 +20,3 @@ def restoreState : RestoreStateM Unit := do
   «associative-modification-operations».restoreState
   «associative-create-then-query».restoreState
   «associative-all-operations-covered».restoreState
-  «slice-producing».restoreState

doc/std/grove/GroveStdlib/Generated/slice-producing.lean

@@ -1,459 +0,0 @@
-import Grove.Framework
-
-/-
-This file is autogenerated by grove. You can manually edit it, for example to resolve merge
-conflicts, but be careful.
--/
-
-open Grove.Framework Widget
-
-namespace GroveStdlib.Generated.«slice-producing»
-
-def «c8a13d6d-7ed6-4cd1-a386-23e2d55ce6f7» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "c8a13d6d-7ed6-4cd1-a386-23e2d55ce6f7"
-  rowId := "c8a13d6d-7ed6-4cd1-a386-23e2d55ce6f7"
-  rowState := #[⟨"String", "String.slice", Declaration.def {
-    name := `String.slice
-    renderedStatement := "String.slice (s : String) (startInclusive endExclusive : s.Pos)\n  (h : startInclusive ≤ endExclusive) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.slice", Declaration.def {
-    name := `String.Slice.slice
-    renderedStatement := "String.Slice.slice (s : String.Slice) (newStart newEnd : s.Pos) (h : newStart ≤ newEnd) :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-forwards", "String.Pos.slice", Declaration.def {
-    name := `String.Pos.slice
-    renderedStatement := "String.Pos.slice {s : String} (pos p₀ p₁ : s.Pos) (h₁ : p₀ ≤ pos) (h₂ : pos ≤ p₁) :\n  (s.slice p₀ p₁ ⋯).Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-backwards", "String.Pos.ofSlice", Declaration.def {
-    name := `String.Pos.ofSlice
-    renderedStatement := "String.Pos.ofSlice {s : String} {p₀ p₁ : s.Pos} {h : p₀ ≤ p₁} (pos : (s.slice p₀ p₁ h).Pos) : s.Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.slice", Declaration.def {
-    name := `String.Slice.Pos.slice
-    renderedStatement := "String.Slice.Pos.slice {s : String.Slice} (pos p₀ p₁ : s.Pos) (h₁ : p₀ ≤ pos) (h₂ : pos ≤ p₁) :\n  (s.slice p₀ p₁ ⋯).Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofSlice", Declaration.def {
-    name := `String.Slice.Pos.ofSlice
-    renderedStatement := "String.Slice.Pos.ofSlice {s : String.Slice} {p₀ p₁ : s.Pos} {h : p₀ ≤ p₁}\n  (pos : (s.slice p₀ p₁ h).Pos) : s.Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-noproof", "String.Pos.sliceOrPanic", Declaration.def {
-    name := `String.Pos.sliceOrPanic
-    renderedStatement := "String.Pos.sliceOrPanic {s : String} (pos p₀ p₁ : s.Pos) {h : p₀ ≤ p₁} : (s.slice p₀ p₁ h).Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-noproof", "String.Slice.Pos.sliceOrPanic", Declaration.def {
-    name := `String.Slice.Pos.sliceOrPanic
-    renderedStatement := "String.Slice.Pos.sliceOrPanic {s : String.Slice} (pos p₀ p₁ : s.Pos) {h : p₀ ≤ p₁} :\n  (s.slice p₀ p₁ h).Pos"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .done
-    comment := ""
-  }
-def «21b4fdfd-f8b3-44f5-a59e-57f1dc1d6819» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "21b4fdfd-f8b3-44f5-a59e-57f1dc1d6819"
-  rowId := "21b4fdfd-f8b3-44f5-a59e-57f1dc1d6819"
-  rowState := #[⟨"String", "String.slice?", Declaration.def {
-    name := `String.slice?
-    renderedStatement := "String.slice? (s : String) (startInclusive endExclusive : s.Pos) : Option String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.slice?", Declaration.def {
-    name := `String.Slice.slice?
-    renderedStatement := "String.Slice.slice? (s : String.Slice) (newStart newEnd : s.Pos) : Option String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .postponed
-    comment := "Would be good to have better support"
-  }
-def «6f2b6ecb-2f0c-4e45-9da3-eb7f2e15eff0» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "6f2b6ecb-2f0c-4e45-9da3-eb7f2e15eff0"
-  rowId := "6f2b6ecb-2f0c-4e45-9da3-eb7f2e15eff0"
-  rowState := #[⟨"String", "String.slice!", Declaration.def {
-    name := `String.slice!
-    renderedStatement := "String.slice! (s : String) (p₁ p₂ : s.Pos) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.slice!", Declaration.def {
-    name := `String.Slice.slice!
-    renderedStatement := "String.Slice.slice! (s : String.Slice) (newStart newEnd : s.Pos) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-forwards", "String.Pos.slice!", Declaration.def {
-    name := `String.Pos.slice!
-    renderedStatement := "String.Pos.slice! {s : String} (pos p₀ p₁ : s.Pos) : (s.slice! p₀ p₁).Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-backwards", "String.Pos.ofSlice!", Declaration.def {
-    name := `String.Pos.ofSlice!
-    renderedStatement := "String.Pos.ofSlice! {s : String} {p₀ p₁ : s.Pos} (pos : (s.slice! p₀ p₁).Pos) : s.Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.slice!", Declaration.def {
-    name := `String.Slice.Pos.slice!
-    renderedStatement := "String.Slice.Pos.slice! {s : String.Slice} (pos p₀ p₁ : s.Pos) : (s.slice! p₀ p₁).Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofSlice!", Declaration.def {
-    name := `String.Slice.Pos.ofSlice!
-    renderedStatement := "String.Slice.Pos.ofSlice! {s : String.Slice} {p₀ p₁ : s.Pos} (pos : (s.slice! p₀ p₁).Pos) : s.Pos"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .done
-    comment := ""
-  }
-def «a3bdf66d-bc11-4019-aee9-2f1c1701de52» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "a3bdf66d-bc11-4019-aee9-2f1c1701de52"
-  rowId := "a3bdf66d-bc11-4019-aee9-2f1c1701de52"
-  rowState := #[⟨"String", "String.trimAsciiStart", Declaration.def {
-    name := `String.trimAsciiStart
-    renderedStatement := "String.trimAsciiStart (s : String) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.trimAsciiStart", Declaration.def {
-    name := `String.Slice.trimAsciiStart
-    renderedStatement := "String.Slice.trimAsciiStart (s : String.Slice) : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing `of` version at least"
-  }
-def «f12b2730-7a4d-465c-8a6d-9d051c300fd5» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "f12b2730-7a4d-465c-8a6d-9d051c300fd5"
-  rowId := "f12b2730-7a4d-465c-8a6d-9d051c300fd5"
-  rowState := #[⟨"String", "String.trimAsciiEnd", Declaration.def {
-    name := `String.trimAsciiEnd
-    renderedStatement := "String.trimAsciiEnd (s : String) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.trimAsciiEnd", Declaration.def {
-    name := `String.Slice.trimAsciiEnd
-    renderedStatement := "String.Slice.trimAsciiEnd (s : String.Slice) : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing `of` version at least"
-  }
-def «32307b55-d6d1-4756-a947-dbe4dfde573c» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "32307b55-d6d1-4756-a947-dbe4dfde573c"
-  rowId := "32307b55-d6d1-4756-a947-dbe4dfde573c"
-  rowState := #[⟨"String", "String.trimAscii", Declaration.def {
-    name := `String.trimAscii
-    renderedStatement := "String.trimAscii (s : String) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.trimAscii", Declaration.def {
-    name := `String.Slice.trimAscii
-    renderedStatement := "String.Slice.trimAscii (s : String.Slice) : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing `of` version at least\n"
-  }
-def «dce95a38-f55a-4d6a-ae79-078ffe4b5c15» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "dce95a38-f55a-4d6a-ae79-078ffe4b5c15"
-  rowId := "dce95a38-f55a-4d6a-ae79-078ffe4b5c15"
-  rowState := #[⟨"String", "String.toSlice", Declaration.def {
-    name := `String.toSlice
-    renderedStatement := "String.toSlice (s : String) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-forwards", "String.Pos.toSlice", Declaration.def {
-    name := `String.Pos.toSlice
-    renderedStatement := "String.Pos.toSlice {s : String} (pos : s.Pos) : s.toSlice.Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-pos-backwards", "String.Pos.ofToSlice", Declaration.def {
-    name := `String.Pos.ofToSlice
-    renderedStatement := "String.Pos.ofToSlice {s : String} (pos : s.toSlice.Pos) : s.Pos"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .done
-    comment := ""
-  }
-def «005a3f30-5dab-493f-b168-32c36a2bdf7c» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "005a3f30-5dab-493f-b168-32c36a2bdf7c"
-  rowId := "005a3f30-5dab-493f-b168-32c36a2bdf7c"
-  rowState := #[⟨"String.Slice", "String.Slice.str", Declaration.def {
-    name := `String.Slice.str
-    renderedStatement := "String.Slice.str (self : String.Slice) : String"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.str", Declaration.def {
-    name := `String.Slice.Pos.str
-    renderedStatement := "String.Slice.Pos.str {s : String.Slice} (pos : s.Pos) : s.str.Pos"
-    isDeprecated := false
-  }
-⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofStr", Declaration.def {
-    name := `String.Slice.Pos.ofStr
-    renderedStatement := "String.Slice.Pos.ofStr {s : String.Slice} (pos : s.str.Pos) (h₁ : s.startInclusive ≤ pos)\n  (h₂ : pos ≤ s.endExclusive) : s.Pos"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing `no proof` version\n"
-  }
-def «5f1a154c-ae2f-43a1-9409-2ce95b163ef3» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "5f1a154c-ae2f-43a1-9409-2ce95b163ef3"
-  rowId := "5f1a154c-ae2f-43a1-9409-2ce95b163ef3"
-  rowState := #[⟨"String", "String.drop", Declaration.def {
-    name := `String.drop
-    renderedStatement := "String.drop (s : String) (n : Nat) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.drop", Declaration.def {
-    name := `String.Slice.drop
-    renderedStatement := "String.Slice.drop (s : String.Slice) (n : Nat) : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «179518d1-ad07-4b2b-8ffe-3b7616e4c4ab» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "179518d1-ad07-4b2b-8ffe-3b7616e4c4ab"
-  rowId := "179518d1-ad07-4b2b-8ffe-3b7616e4c4ab"
-  rowState := #[⟨"String", "String.take", Declaration.def {
-    name := `String.take
-    renderedStatement := "String.take (s : String) (n : Nat) : String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.take", Declaration.def {
-    name := `String.Slice.take
-    renderedStatement := "String.Slice.take (s : String.Slice) (n : Nat) : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «55c587fd-a7a8-4633-a4ae-e2c4e768ad28» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "55c587fd-a7a8-4633-a4ae-e2c4e768ad28"
-  rowId := "55c587fd-a7a8-4633-a4ae-e2c4e768ad28"
-  rowState := #[⟨"String", "String.dropWhile", Declaration.def {
-    name := `String.dropWhile
-    renderedStatement := "String.dropWhile {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.ForwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropWhile", Declaration.def {
-    name := `String.Slice.dropWhile
-    renderedStatement := "String.Slice.dropWhile {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.ForwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «d4444684-4279-4400-9be2-561a7cdb32c1» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "d4444684-4279-4400-9be2-561a7cdb32c1"
-  rowId := "d4444684-4279-4400-9be2-561a7cdb32c1"
-  rowState := #[⟨"String", "String.takeWhile", Declaration.def {
-    name := `String.takeWhile
-    renderedStatement := "String.takeWhile {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.ForwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.takeWhile", Declaration.def {
-    name := `String.Slice.takeWhile
-    renderedStatement := "String.Slice.takeWhile {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.ForwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «1c9e6689-65a0-4d4b-b001-256e83917d98» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "1c9e6689-65a0-4d4b-b001-256e83917d98"
-  rowId := "1c9e6689-65a0-4d4b-b001-256e83917d98"
-  rowState := #[⟨"String", "String.dropEndWhile", Declaration.def {
-    name := `String.dropEndWhile
-    renderedStatement := "String.dropEndWhile {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.BackwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropEndWhile", Declaration.def {
-    name := `String.Slice.dropEndWhile
-    renderedStatement := "String.Slice.dropEndWhile {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.BackwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «b836052b-3470-4a8e-8989-6951c898de37» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "b836052b-3470-4a8e-8989-6951c898de37"
-  rowId := "b836052b-3470-4a8e-8989-6951c898de37"
-  rowState := #[⟨"String", "String.takeEndWhile", Declaration.def {
-    name := `String.takeEndWhile
-    renderedStatement := "String.takeEndWhile {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.BackwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.takeEndWhile", Declaration.def {
-    name := `String.Slice.takeEndWhile
-    renderedStatement := "String.Slice.takeEndWhile {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.BackwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «5aa777d8-9642-43d8-9e20-30400fb8bb9d» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "5aa777d8-9642-43d8-9e20-30400fb8bb9d"
-  rowId := "5aa777d8-9642-43d8-9e20-30400fb8bb9d"
-  rowState := #[⟨"String", "String.dropPrefix", Declaration.def {
-    name := `String.dropPrefix
-    renderedStatement := "String.dropPrefix {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.ForwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropPrefix", Declaration.def {
-    name := `String.Slice.dropPrefix
-    renderedStatement := "String.Slice.dropPrefix {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.ForwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «80e3869d-fcfe-459d-8433-fe221f7b3c7a» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "80e3869d-fcfe-459d-8433-fe221f7b3c7a"
-  rowId := "80e3869d-fcfe-459d-8433-fe221f7b3c7a"
-  rowState := #[⟨"String", "String.dropSuffix", Declaration.def {
-    name := `String.dropSuffix
-    renderedStatement := "String.dropSuffix {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.BackwardPattern pat] :\n  String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropSuffix", Declaration.def {
-    name := `String.Slice.dropSuffix
-    renderedStatement := "String.Slice.dropSuffix {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.BackwardPattern pat] : String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .bad
-    comment := "Missing position transformations"
-  }
-def «4feda3e0-903b-4d52-b34e-0af70f7866e0» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "4feda3e0-903b-4d52-b34e-0af70f7866e0"
-  rowId := "4feda3e0-903b-4d52-b34e-0af70f7866e0"
-  rowState := #[⟨"String", "String.dropPrefix?", Declaration.def {
-    name := `String.dropPrefix?
-    renderedStatement := "String.dropPrefix? {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.ForwardPattern pat] :\n  Option String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropPrefix?", Declaration.def {
-    name := `String.Slice.dropPrefix?
-    renderedStatement := "String.Slice.dropPrefix? {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.ForwardPattern pat] : Option String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .postponed
-    comment := "Missing position transformations"
-  }
-def «45ca44c8-fbd5-4400-8297-a60778f302b0» : AssociationTable.Fact .declaration where
-  widgetId := "slice-producing"
-  factId := "45ca44c8-fbd5-4400-8297-a60778f302b0"
-  rowId := "45ca44c8-fbd5-4400-8297-a60778f302b0"
-  rowState := #[⟨"String", "String.dropSuffix?", Declaration.def {
-    name := `String.dropSuffix?
-    renderedStatement := "String.dropSuffix? {ρ : Type} (s : String) (pat : ρ) [String.Slice.Pattern.BackwardPattern pat] :\n  Option String.Slice"
-    isDeprecated := false
-  }
-⟩,⟨"String.Slice", "String.Slice.dropSuffix?", Declaration.def {
-    name := `String.Slice.dropSuffix?
-    renderedStatement := "String.Slice.dropSuffix? {ρ : Type} (s : String.Slice) (pat : ρ)\n  [String.Slice.Pattern.BackwardPattern pat] : Option String.Slice"
-    isDeprecated := false
-  }
-⟩,]
-  metadata := {
-    status := .postponed
-    comment := "Missing position transformations"
-  }
-
-def table : AssociationTable.Data .declaration where
-  widgetId := "slice-producing"
-  rows := #[
-    ⟨"c8a13d6d-7ed6-4cd1-a386-23e2d55ce6f7", "slice", #[⟨"String", "String.slice"⟩,⟨"String.Slice", "String.Slice.slice"⟩,⟨"string-pos-forwards", "String.Pos.slice"⟩,⟨"string-pos-backwards", "String.Pos.ofSlice"⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.slice"⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofSlice"⟩,⟨"string-pos-noproof", "String.Pos.sliceOrPanic"⟩,⟨"string-slice-pos-noproof", "String.Slice.Pos.sliceOrPanic"⟩,]⟩,
-    ⟨"21b4fdfd-f8b3-44f5-a59e-57f1dc1d6819", "slice?", #[⟨"String", "String.slice?"⟩,⟨"String.Slice", "String.Slice.slice?"⟩,]⟩,
-    ⟨"6f2b6ecb-2f0c-4e45-9da3-eb7f2e15eff0", "slice!", #[⟨"String", "String.slice!"⟩,⟨"String.Slice", "String.Slice.slice!"⟩,⟨"string-pos-forwards", "String.Pos.slice!"⟩,⟨"string-pos-backwards", "String.Pos.ofSlice!"⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.slice!"⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofSlice!"⟩,]⟩,
-    ⟨"a3bdf66d-bc11-4019-aee9-2f1c1701de52", "trimAsciiStart", #[⟨"String", "String.trimAsciiStart"⟩,⟨"String.Slice", "String.Slice.trimAsciiStart"⟩,]⟩,
-    ⟨"f12b2730-7a4d-465c-8a6d-9d051c300fd5", "trimAsciiEnd", #[⟨"String", "String.trimAsciiEnd"⟩,⟨"String.Slice", "String.Slice.trimAsciiEnd"⟩,]⟩,
-    ⟨"32307b55-d6d1-4756-a947-dbe4dfde573c", "trimAscii", #[⟨"String", "String.trimAscii"⟩,⟨"String.Slice", "String.Slice.trimAscii"⟩,]⟩,
-    ⟨"dce95a38-f55a-4d6a-ae79-078ffe4b5c15", "toSlice", #[⟨"String", "String.toSlice"⟩,⟨"string-pos-forwards", "String.Pos.toSlice"⟩,⟨"string-pos-backwards", "String.Pos.ofToSlice"⟩,]⟩,
-    ⟨"005a3f30-5dab-493f-b168-32c36a2bdf7c", "str", #[⟨"String.Slice", "String.Slice.str"⟩,⟨"string-slice-pos-forwards", "String.Slice.Pos.str"⟩,⟨"string-slice-pos-backwards", "String.Slice.Pos.ofStr"⟩,]⟩,
-    ⟨"5f1a154c-ae2f-43a1-9409-2ce95b163ef3", "drop", #[⟨"String", "String.drop"⟩,⟨"String.Slice", "String.Slice.drop"⟩,]⟩,
-    ⟨"179518d1-ad07-4b2b-8ffe-3b7616e4c4ab", "take", #[⟨"String", "String.take"⟩,⟨"String.Slice", "String.Slice.take"⟩,]⟩,
-    ⟨"55c587fd-a7a8-4633-a4ae-e2c4e768ad28", "dropWhile", #[⟨"String", "String.dropWhile"⟩,⟨"String.Slice", "String.Slice.dropWhile"⟩,]⟩,
-    ⟨"d4444684-4279-4400-9be2-561a7cdb32c1", "takeWhile", #[⟨"String", "String.takeWhile"⟩,⟨"String.Slice", "String.Slice.takeWhile"⟩,]⟩,
-    ⟨"1c9e6689-65a0-4d4b-b001-256e83917d98", "dropEndWhile", #[⟨"String", "String.dropEndWhile"⟩,⟨"String.Slice", "String.Slice.dropEndWhile"⟩,]⟩,
-    ⟨"b836052b-3470-4a8e-8989-6951c898de37", "takeEndWhile", #[⟨"String", "String.takeEndWhile"⟩,⟨"String.Slice", "String.Slice.takeEndWhile"⟩,]⟩,
-    ⟨"5aa777d8-9642-43d8-9e20-30400fb8bb9d", "dropPrefix", #[⟨"String", "String.dropPrefix"⟩,⟨"String.Slice", "String.Slice.dropPrefix"⟩,]⟩,
-    ⟨"80e3869d-fcfe-459d-8433-fe221f7b3c7a", "dropSuffix", #[⟨"String", "String.dropSuffix"⟩,⟨"String.Slice", "String.Slice.dropSuffix"⟩,]⟩,
-    ⟨"4feda3e0-903b-4d52-b34e-0af70f7866e0", "dropPrefix?", #[⟨"String", "String.dropPrefix?"⟩,⟨"String.Slice", "String.Slice.dropPrefix?"⟩,]⟩,
-    ⟨"45ca44c8-fbd5-4400-8297-a60778f302b0", "dropSuffix?", #[⟨"String", "String.dropSuffix?"⟩,⟨"String.Slice", "String.Slice.dropSuffix?"⟩,]⟩,
-  ]
-  facts := #[
-    «c8a13d6d-7ed6-4cd1-a386-23e2d55ce6f7»,
-    «21b4fdfd-f8b3-44f5-a59e-57f1dc1d6819»,
-    «6f2b6ecb-2f0c-4e45-9da3-eb7f2e15eff0»,
-    «a3bdf66d-bc11-4019-aee9-2f1c1701de52»,
-    «f12b2730-7a4d-465c-8a6d-9d051c300fd5»,
-    «32307b55-d6d1-4756-a947-dbe4dfde573c»,
-    «dce95a38-f55a-4d6a-ae79-078ffe4b5c15»,
-    «005a3f30-5dab-493f-b168-32c36a2bdf7c»,
-    «5f1a154c-ae2f-43a1-9409-2ce95b163ef3»,
-    «179518d1-ad07-4b2b-8ffe-3b7616e4c4ab»,
-    «55c587fd-a7a8-4633-a4ae-e2c4e768ad28»,
-    «d4444684-4279-4400-9be2-561a7cdb32c1»,
-    «1c9e6689-65a0-4d4b-b001-256e83917d98»,
-    «b836052b-3470-4a8e-8989-6951c898de37»,
-    «5aa777d8-9642-43d8-9e20-30400fb8bb9d»,
-    «80e3869d-fcfe-459d-8433-fe221f7b3c7a»,
-    «4feda3e0-903b-4d52-b34e-0af70f7866e0»,
-    «45ca44c8-fbd5-4400-8297-a60778f302b0»,
-  ]
-
-def restoreState : RestoreStateM Unit := do
-  addAssociationTable table

doc/std/grove/GroveStdlib/Std.lean

@@ -15,7 +15,7 @@ namespace GroveStdlib
 namespace Std
 
 def introduction : Node :=
-  .text ⟨"introduction", "Welcome to the interactive Lean standard library outline!"⟩
+  .text "Welcome to the interactive Lean standard library outline!"
 
 end Std
 

doc/std/grove/GroveStdlib/Std/CoreTypesAndOperations/StringsAndFormatting.lean

@@ -11,87 +11,9 @@ namespace GroveStdlib.Std.CoreTypesAndOperations
 
 namespace StringsAndFormatting
 
-open Lean Meta
-
-def introduction : Text where
-  id := "string-introduction"
-  content := Grove.Markdown.render [
-    .h1 "The Lean string library",
-    .text "The Lean standard library contains a fully-featured string library, centered around the types `String` and `String.Slice`.",
-    .text "`String` is defined as the subtype of `ByteArray` of valid UTF-8 strings. A `String.Slice` is a `String` together with a start and end position.",
-    .text "`String` is equivalent to `List Char`, but it has a more efficient runtime representation. While the logical model based on `ByteArray` is overwritten in the runtime, the runtime implementation is very similar to the logical model, with the main difference being that the length of a string in Unicode code points is cached in the runtime implementation.",
-    .text "We are considering removing this feature in the future (i.e., deprecating `String.length`), as the number of UTF-8 codepoints in a string is not particularly useful, and if needed it can be computed in linear time using `s.positions.count`."
-  ]
-
-def highLevelStringTypes : List Lean.Name :=
-  [`String, `String.Slice, `String.Pos, `String.Slice.Pos]
-
-def creatingStringsAndSlices : Text where
-  id := "transforming-strings-and-slices"
-  content := Grove.Markdown.render [
-    .h2 "Transforming strings and slices",
-    .text "The Lean standard library contains a number of functions that take one or more strings and slices and return a string or a slice.",
-    .text "If possible, these functions should avoid allocating a new string, and return a slice of their input(s) instead.",
-    .text "Usually, for every operation `f`, there will be functions `String.f` and `String.Slice.f`, where `String.f s` is defined as `String.Slice.f s.toSlice`.",
-    .text "In particular, functions that transform strings and slices should live in the `String` and `String.Slice` namespaces even if they involve a `String.Pos`/`String.Slice.Pos` (like `String.sliceTo`), for reasons that will become clear shortly.",
-
-    .h3 "Transforming positions",
-    .text "Since positions on strings and slices are dependent on the string or slice, whenever users transform a string/slice, they will be interested in interpreting positions on the original string/slice as positions on the result, or vice versa.",
-    .text "Consequently, every operation that transforms a string or slice should come with a corresponding set of transformations between positions, usually in both directions, possibly with one of the directions being conditional.",
-    .text "For example, given a string `s` and a position `p` on `s`, we have the slice `s.sliceFrom p`, which is the slice from `p` to the end of `s`. A position on `s.sliceFrom p` can always be interpreted as a position on `s`. This is the \"backwards\" transformation. Conversely, a position `q` on `s` can be interpreted as a position on `s.sliceFrom p` as long as `p ≤ q`. This is the conditional forwards direction.",
-    .text "The convention for naming these transformations is that the forwards transformation should have the same name as the transformation on strings/slices, but it should be located in the `String.Pos` or `String.Slice.Pos` namespace, depending on the type of the starting position (so that dot notation is possible for the forward direction). The backwards transformation should have the same name as the operation on strings/slices, but with an `of` prefix, and live in the same namespace as the forwards transformation (so in general dot notation will not be available).",
-    .text "So, in the `sliceFrom` example, the forward direction would be called `String.Pos.sliceFrom`, while the backwards direction should be called `String.Pos.ofSliceFrom` (not `String.Slice.Pos.ofSliceFrom`).",
-    .text "If one of the directions is conditional, it should have a corresponding panicking operation that does not require a proof; in our example this would be `String.Pos.sliceFrom!`.",
-    .text "Sometimes there is a name clash for the panicking operations if the operation on strings is already panicking. For example, there are both `String.slice` and `String.slice!`. If the original operation is already panicking, we only provide panicking transformation operations. But now `String.Pos.slice!` could refer both to the panicking forwards transformation associated with `String.slice`, and also to the (only) forwards transformation associated with `String.slice!`. In this situation, we use an `orPanic` suffix to disambiguate. So the panicking forwards operation associated with `String.slice` is called `String.Pos.sliceOrPanic`, and the forwards operation associated with `String.slice!` is called `String.Pos.slice!`."
-  ]
-
--- TODO: also include the `HAppend` instance(s)
-def sliceProducing : AssociationTable (β := Alias Lean.Name) .declaration
-    [`String, `String.Slice,
-     Alias.mk `String.Pos "string-pos-forwards" "String.Pos (forwards)",
-     Alias.mk `String.Pos "string-pos-backwards" "String.Pos (backwards)",
-     Alias.mk `String.Pos "string-pos-noproof" "String.Pos (no proof)",
-     Alias.mk `String.Slice.Pos "string-slice-pos-forwards" "String.Slice.Pos (forwards)",
-     Alias.mk `String.Slice.Pos "string-slice-pos-backwards" "String.Slice.Pos (backwards)",
-     Alias.mk `String.Slice.Pos "string-slice-pos-noproof" "String.Slice.Pos (no proof)"] where
-  id := "slice-producing"
-  title := "String functions returning strings or slices"
-  description := "Operations on strings and string slices that themselves return a new string slice."
-  dataSources n := DataSource.definitionsInNamespace n.inner
-
-def sliceProducingComplete : Assertion where
-  widgetId := "slice-producing-complete"
-  title := "Slice-producing table is complete"
-  description := "All functions in the `String.**` namespace that return a string or a slice are covered in the table"
-  check := do
-    let mut ans := #[]
-    let covered := Std.HashSet.ofArray (← valuesInAssociationTable sliceProducing)
-    let pred : DataSource.DeclarationPredicate :=
-      DataSource.DeclarationPredicate.all [.isDefinition, .not .isDeprecated,
-        .notInNamespace `String.Pos.Raw, .notInNamespace `String.Legacy,
-        .not .isInstance]
-    let env ← getEnv
-    for name in ← declarationsMatching `String pred do
-      let some c := env.find? name | continue
-      if c.type.getForallBody.getUsedConstants.any (fun n => n == ``String || n == ``String.Slice) then
-        let success : Bool := name.toString ∈ covered
-        ans := ans.push {
-          assertionId := name.toString
-          description := s!"`{name}` should appear in the table."
-          passed := success
-          message := s!"`{name}` was{if success then "" else " not"} found in the table."
-        }
-    return ans
-
 end StringsAndFormatting
 
-open StringsAndFormatting
-
 def stringsAndFormatting : Node :=
-  .section "strings-and-formatting" "Strings and formatting"
-    #[.text introduction,
-      .text creatingStringsAndSlices,
-      .associationTable sliceProducing,
-      .assertion sliceProducingComplete]
+  .section "strings-and-formatting" "Strings and formatting" #[]
 
-end GroveStdlib.Std.CoreTypesAndOperations
+end GroveStdlib.Std.CoreTypesAndOperations

doc/std/grove/lake-manifest.json

@@ -5,7 +5,7 @@
    "type": "git",
    "subDir": "backend",
    "scope": "",
-   "rev": "c580a425c9b7fa2aebaec2a1d8de16b2e2283c40",
+   "rev": "3e8aabdea58c11813c5d3b7eeb187ded44ee9a34",
    "name": "grove",
    "manifestFile": "lake-manifest.json",
    "inputRev": "master",
@@ -15,10 +15,10 @@
    "type": "git",
    "subDir": null,
    "scope": "leanprover",
-   "rev": "d9fc8ae23024be37424a189982c92356e37935c8",
+   "rev": "1604206fcd0462da9a241beeac0e2df471647435",
    "name": "Cli",
    "manifestFile": "lake-manifest.json",
-   "inputRev": "nightly-testing",
+   "inputRev": "main",
    "inherited": true,
    "configFile": "lakefile.toml"}],
  "name": "grovestdlib",

doc/style.md

@@ -810,7 +810,7 @@ Docstrings for constants should have the following structure:
 
 The **short summary** should be 1–3 sentences (ideally 1) and provide
 enough information for most readers to quickly decide whether the
-constant is relevant to their task. The first (or only) sentence of
+docstring is relevant to their task. The first (or only) sentence of
 the short summary should be a *sentence fragment* in which the subject
 is implied to be the documented item, written in present tense
 indicative, or a *noun phrase* that characterizes the documented
@@ -1123,110 +1123,6 @@ infix:50 " ⇔ " => Bijection
 recommended_spelling "bij" for "⇔" in [Bijection, «term_⇔_»]
 ```
 
-#### Tactics
-
-Docstrings for tactics should have the following structure:
-
-* Short summary
-* Details
-* Variants
-* Examples
-
-Sometimes more than one declaration is needed to implement what the user
-sees as a single tactic. In that case, only one declaration should have
-the associated docstring, and the others should have the `tactic_alt`
-attribute to mark them as an implementation detail.
-
-The **short summary** should be 1–3 sentences (ideally 1) and provide
-enough information for most readers to quickly decide whether the
-tactic is relevant to their task. The first (or only) sentence of
-the short summary should be a full sentence in which the subject
-is an example invocation of the tactic, written in present tense
-indicative. If the example tactic invocation names parameters, then the
-short summary may refer to them. For the example invocation, prefer the
-simplest or most typical example. Explain more complicated forms in the
-variants section. If needed, abbreviate the invocation by naming part of
-the syntax and expanding it in the next sentence. The summary should be
-written as a single paragraph.
-
-**Details**, if needed, may be 1-3 paragraphs that describe further
-relevant information. They may insert links as needed. This section
-should fully explain the scope of the tactic: its syntax format,
-on which goals it works and what the resulting goal(s) look like. It
-should be clear whether the tactic fails if it does not close the main
-goal and whether it creates any side goals. The details may include
-explanatory examples that can’t necessarily be machine checked and
-don’t fit the format.
-
-If the tactic is extensible using `macro_rules`, mention this in the
-details, with a link to `lean-manual://section/tactic-macro-extension`
-and give a one-line example. If the tactic provides an attribute or a
-command that allows the user to extend its behavior, the documentation
-on how to extend the tactic belongs to that attribute or command. In the
-tactic docstring, use a single sentence to refer the reader to this
-further documentation.
-
-**Variants**, if needed, should be a bulleted list describing different
-options and forms of the same tactic. The reader should be able to parse
-and understand the parts of a tactic invocation they are hovering over,
-using this list. Each list item should describe an individual variant
-and take one of two formats: the **short summary** as above, or a
-**named list item**. A named list item consists of a title in bold
-followed by an indented short paragraph.
-
-Variants should be explained from the perspective of the tactic's users, not
-their implementers. A tactic that is implemented as a single Lean parser may
-have multiple variants from the perspective of users, while a tactic that is
-implemented as multiple parsers may have no variants, but merely an optional
-part of the syntax.
-
-**Examples** should start with the line `Examples:` (or `Example:` if
-there’s exactly one). The section should consist of a sequence of code
-blocks, each showing a Lean declaration (usually with the `example`
-keyword) that invokes the tactic. When the effect of the tactic is not
-clear from the code, you can use code comments to describe this. Do
-not include text between examples, because it can be unclear whether
-the text refers to the code before or after the example.
-
-##### Example
-
-````
-`rw [e]` uses the expression `e` as a rewrite rule on the main goal,
-then tries to close the goal by "cheap" (reducible) `rfl`.
-
-If `e` is a defined constant, then the equational theorems associated with `e`
-are used. This provides a convenient way to unfold `e`. If `e` has parameters,
-the tactic will try to fill these in by unification with the matching part of
-the target. Parameters are only filled in once per rule, restricting which
-later rewrites can be found. Parameters that are not filled in after
-unification will create side goals. If the `rfl` fails to close the main goal,
-no error is raised.
-
-`rw` may fail to rewrite terms "under binders", such as `∀ x, ...` or `∃ x,
-...`. `rw` can also fail with a "motive is type incorrect" error in the context
-of dependent types. In these cases, consider using `simp only`.
-
-* `rw [e₁, ... eₙ]` applies the given rules sequentially.
-* `rw [← e]` or `rw [<- e]` applies the rewrite in the reverse direction.
-* `rw [e] at l` rewrites with `e` at location(s) `l`.
-* `rw (occs := .pos L) [e]`, where `L` is a literal list of natural numbers,
-  only rewrites the given occurrences in the target. Occurrences count from 1.
-* `rw (occs := .neg L) [e]`, where `L` is a literal list of natural numbers,
-  skips rewriting the given occurrences in the target. Occurrences count from 1.
-
-Examples:
-
-```lean
-example {a b : Nat} (h : a + a = b) : (a + a) + (a + a) = b + b := by rw [h]
-```
-
-```lean
-example {f : Nat -> Nat} (h : ∀ x, f x = 1) (a b : Nat) : f a = f b := by
-  rw [h] -- `rw` instantiates `h` only once, so this is equivalent to: `rw [h a]`
-  -- goal: ⊢ 1 = f b
-  rw [h] -- equivalent to: `rw [h b]`
-```
-````
 
 
 ## Dictionary

releases_drafts/module-system.md

@@ -1,54 +0,0 @@
-This release introduces the Lean module system, which allows files to
-control the visibility of their contents for other files. In previous
-releases, this feature was available as a preview when the option
-`experimental.module` was set to `true`; it is now a fully supported
-feature of Lean.
-
-# Benefits
-
-Because modules reduce the amount of information exposed to other
-code, they speed up rebuilds because irrelevant changes can be
-ignored, they make it possible to be deliberate about API evolution by
-hiding details that may change from clients, they help proofs be
-checked faster by avoiding accidentally unfolding definitions, and
-they lead to smaller executable files through improved dead code
-elimination.
-
-# Visibility
-
-A source file is a module if it begins with the `module` keyword.  By
-default, declarations in a module are private; the `public` modifier
-exports them. Proofs of theorems and bodies of definitions are private
-by default even when their signatures are public; the bodies of
-definitions can be made public by adding the `@[expose]`
-attribute. Theorems and opaque constants never expose their bodies.
-
-`public section` and `@[expose] section` change the default visibility
-of declarations in the section.
-
-# Imports
-
-Modules may only import other modules. By default, `import` adds the
-public information of the imported module to the private scope of the
-current module. Adding the `public` modifier to an import places the
-imported modules's public information in the public scope of the
-current module, exposing it in turn to the current module's clients.
-
-Within a package, `import all` can be used to import another module's
-private scope into the current module; this can be used to separate
-lemmas or tests from definition modules without exposing details to
-downstream clients.
-
-# Meta Code
-
-Code used in metaprograms must be marked `meta`. This ensures that the
-code is compiled and available for execution when it is needed during
-elaboration. Meta code may only reference other meta code. A whole
-module can be made available in the meta phase using `meta import`;
-this allows code to be shared across phases by importing the module in
-each phase. Code that is reachable from public metaprograms must be
-imported via `public meta import`, while local metaprograms can use
-plain `meta import` for their dependencies.
-
-
-The module system is described in detail in [the Lean language reference](https://lean-reference-manual-review.netlify.app/find/?domain=Verso.Genre.Manual.section&name=files).

script/AnalyzeGrindAnnotations.lean

@@ -0,0 +1,132 @@
+/-
+Copyright (c) 2025 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+import Lean
+
+namespace Lean.Meta.Grind.Analyzer
+
+
+/-!
+A simple E-matching annotation analyzer.
+For each theorem annotated as an E-matching candidate, it creates an artificial goal, executes `grind` and shows the
+number of instances created.
+For a theorem of the form `params -> type`, the artificial goal is of the form `params -> type -> False`.
+-/
+
+/--
+`grind` configuration for the analyzer. We disable case-splits and lookahead,
+increase the number of generations, and limit the number of instances generated.
+-/
+def config : Grind.Config := {
+  splits       := 0
+  lookahead    := false
+  mbtc         := false
+  ematch       := 20
+  instances    := 100
+  gen          := 10
+}
+
+structure Config where
+  /-- Minimum number of instantiations to trigger summary report -/
+  min : Nat := 10
+  /-- Minimum number of instantiations to trigger detailed report -/
+  detailed : Nat := 50
+
+def mkParams : MetaM Params := do
+  let params ← Grind.mkParams config
+  let ematch ← getEMatchTheorems
+  let casesTypes ← Grind.getCasesTypes
+  return { params with ematch, casesTypes }
+
+/-- Returns the total number of generated instances.  -/
+private def sum (cs : PHashMap Origin Nat) : Nat := Id.run do
+  let mut r := 0
+  for (_, c) in cs do
+    r := r + c
+  return r
+
+private def thmsToMessageData (thms : PHashMap Origin Nat) : MetaM MessageData := do
+  let data := thms.toArray.filterMap fun (origin, c) =>
+    match origin with
+    | .decl declName => some (declName, c)
+    | _ => none
+  let data := data.qsort fun (d₁, c₁) (d₂, c₂) => if c₁ == c₂ then Name.lt d₁ d₂ else c₁ > c₂
+  let data ← data.mapM fun (declName, counter) =>
+    return .trace { cls := `thm } m!"{.ofConst (← mkConstWithLevelParams declName)} ↦ {counter}" #[]
+  return .trace { cls := `thm } "instances" data
+
+/--
+Analyzes theorem `declName`. That is, creates the artificial goal based on `declName` type,
+and invokes `grind` on it.
+-/
+def analyzeEMatchTheorem (declName : Name) (c : Config) : MetaM Unit := do
+  let info ← getConstInfo declName
+  let mvarId ← forallTelescope info.type fun _ type => do
+    withLocalDeclD `h type fun _ => do
+      return (← mkFreshExprMVar (mkConst ``False)).mvarId!
+  let result ← Grind.main mvarId (← mkParams) (pure ())
+  let thms := result.counters.thm
+  let s := sum thms
+  if s > c.min then
+    IO.println s!"{declName} : {s}"
+  if s > c.detailed then
+    logInfo m!"{declName}\n{← thmsToMessageData thms}"
+
+-- Not sure why this is failing: `down_pure` perhaps has an unnecessary universe parameter?
+run_meta analyzeEMatchTheorem ``Std.Do.SPred.down_pure {}
+
+/-- Analyzes all theorems in the standard library marked as E-matching theorems. -/
+def analyzeEMatchTheorems (c : Config := {}) : MetaM Unit := do
+  let origins := (← getEMatchTheorems).getOrigins
+  let decls := origins.filterMap fun | .decl declName => some declName | _ => none
+  for declName in decls.mergeSort Name.lt do
+    try
+      analyzeEMatchTheorem declName c
+    catch e =>
+      logError m!"{declName} failed with {e.toMessageData}"
+  logInfo m!"Finished analyzing {decls.length} theorems"
+
+/-- Macro for analyzing E-match theorems with unlimited heartbeats -/
+macro "#analyzeEMatchTheorems" : command => `(
+  set_option maxHeartbeats 0 in
+  run_meta analyzeEMatchTheorems
+)
+
+#analyzeEMatchTheorems
+
+-- -- We can analyze specific theorems using commands such as
+set_option trace.grind.ematch.instance true
+
+-- 1. grind immediately sees `(#[] : Array α) = ([] : List α).toArray` but probably this should be hidden.
+-- 2. `Vector.toArray_empty` keys on `Array.mk []` rather than `#v[].toArray`
+-- I guess we could add `(#[].extract _ _).extract _ _` as a stop pattern.
+run_meta analyzeEMatchTheorem ``Array.extract_empty {}
+
+-- Neither `Option.bind_some` nor `Option.bind_fun_some` fire, because the terms appear inside
+-- lambdas. So we get crazy things like:
+-- `fun x => ((some x).bind some).bind fun x => (some x).bind fun x => (some x).bind some`
+-- We could consider replacing `filterMap_some` with
+-- `filterMap g (filterMap f xs) = filterMap (f >=> g) xs`
+-- to avoid the lambda that `grind` struggles with, but this would require more API around the fish.
+run_meta analyzeEMatchTheorem ``Array.filterMap_some {}
+
+-- Not entirely certain what is wrong here, but certainly
+-- `eq_empty_of_append_eq_empty` is firing too often.
+-- Ideally we could instantiate this is we fine `xs ++ ys` in the same equivalence class,
+-- note just as soon as we see `xs ++ ys`.
+-- I've tried removing this in https://github.com/leanprover/lean4/pull/10162
+run_meta analyzeEMatchTheorem ``Array.range'_succ {}
+
+-- Perhaps the same story here.
+run_meta analyzeEMatchTheorem ``Array.range_succ {}
+
+-- `zip_map_left` and `zip_map_right` are bad grind lemmas,
+-- checking if they can be removed in https://github.com/leanprover/lean4/pull/10163
+run_meta analyzeEMatchTheorem ``Array.zip_map {}
+
+-- It seems crazy to me that as soon as we have `0 >>> n = 0`, we instantiate based on the
+-- pattern `0 >>> n >>> m` by substituting `0` into `0 >>> n` to produce the `0 >>> n >>> n`.
+-- I don't think any forbidden subterms can help us here. I don't know what to do. :-(
+run_meta analyzeEMatchTheorem ``Int.zero_shiftRight {}

script/Shake.lean

@@ -3,21 +3,16 @@ Copyright (c) 2023 Mario Carneiro. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro, Sebastian Ullrich
 -/
-module
-
-import Lean.Environment
+import Lake.CLI.Main
 import Lean.ExtraModUses
 
-import Lake.CLI.Main
-import Lean.Parser.Module
-import Lake.Load.Workspace
-
-/-! # Shake: A Lean import minimizer
+/-! # `lake exe shake` command
 
 This command will check the current project (or a specified target module) and all dependencies for
 unused imports. This works by looking at generated `.olean` files to deduce required imports and
 ensuring that every import is used to contribute some constant or other elaboration dependency
-recorded by `recordExtraModUse` and friends.
+recorded by `recordExtraModUse`. Because recompilation is not needed this is quite fast (about 8
+seconds to check `Mathlib` and all dependencies).
 -/
 
 /-- help string for the command line interface -/
@@ -33,83 +28,13 @@ Options:
   --force
     Skips the `lake build --no-build` sanity check
 
-  --keep-implied
-    Preserves existing imports that are implied by other imports and thus not technically needed
-    anymore
-
-  --keep-prefix
-    If an import `X` would be replaced in favor of a more specific import `X.Y...` it implies,
-    preserves the original import instead. More generally, prefers inserting `import X` even if it
-    was not part of the original imports as long as it was in the original transitive import closure
-    of the current module.
-
-  --keep-public
-    Preserves all `public` imports to avoid breaking changes for external downstream modules
-
-  --add-public
-    Adds new imports as `public` if they have been in the original public closure of that module.
-    In other words, public imports will not be removed from a module unless they are unused even
-    in the private scope, and those that are removed will be re-added as `public` in downstream
-    modules even if only needed in the private scope there. Unlike `--keep-public`, this may
-    introduce breaking changes but will still limit the number of inserted imports.
-
-  --explain
-    Gives constants explaining why each module is needed
-
   --fix
     Apply the suggested fixes directly. Make sure you have a clean checkout
     before running this, so you can review the changes.
-
-  --gh-style
-    Outputs messages that can be parsed by `gh-problem-matcher-wrap`
-
-Annotations:
-  The following annotations can be added to Lean files in order to configure the behavior of
-  `shake`. Only the substring `shake: ` directly followed by a directive is checked for, so multiple
-  directives can be mixed in one line such as `-- shake: keep-downstream, shake: keep-all`, and they
-  can be surrounded by arbitrary comments such as `-- shake: keep (metaprogram output dependency)`.
-
-  * `module -- shake: keep-downstream`:
-    Preserves this module in all (current) downstream modules, adding new imports of it if needed.
-
-  * `module -- shake: keep-all`:
-    Preserves all existing imports in this module as is. New imports now needed because of upstream
-    changes may still be added.
-
-  * `import X -- shake: keep`:
-    Preserves this specific import in the current module. The most common use case is to preserve a
-    public import that will be needed in downstream modules to make sense of the output of a
-    metaprogram defined in this module. For example, if a tactic is defined that may synthesize a
-    reference to a theorem when run, there is no way for `shake` to detect this by itself and the
-    module of that theorem should be publicly imported and annotated with `keep` in the tactic's
-    module.
-    ```
-    public import X  -- shake: keep (metaprogram output dependency)
-
-    ...
-
-    elab \"my_tactic\" : tactic => do
-      ... mkConst ``f -- `f`, defined in `X`, may appear in the output of this tactic
-    ```
 "
 
 open Lean
 
-/-- The parsed CLI arguments. See `help` for more information -/
-structure Args where
-  help : Bool := false
-  keepImplied : Bool := false
-  keepPrefix : Bool := false
-  keepPublic : Bool := false
-  addPublic : Bool := false
-  force : Bool := false
-  githubStyle : Bool := false
-  explain : Bool := false
-  trace : Bool := false
-  fix : Bool := false
-  /-- `<MODULE>..`: the list of root modules to check -/
-  mods : Array Name := #[]
-
 /-- We use `Nat` as a bitset for doing efficient set operations.
 The bit indexes will usually be a module index. -/
 structure Bitset where
@@ -163,7 +88,7 @@ def ofImport : Lean.Import → NeedsKind
 
 end NeedsKind
 
-/-- Logically, a map `NeedsKind → Set ModuleIdx`, or `Set Import`. -/
+/-- Logically, a map `NeedsKind → Bitset`. -/
 structure Needs where
   pub : Bitset
   priv : Bitset
@@ -199,20 +124,6 @@ def Needs.union (needs : Needs) (k : NeedsKind) (s : Bitset) : Needs :=
 def Needs.sub (needs : Needs) (k : NeedsKind) (s : Bitset) : Needs :=
   needs.modify k (fun s' => s' ^^^ (s' ∩ s))
 
-instance : Union Needs where
-  union a b := {
-    pub := a.pub ∪ b.pub
-    priv := a.priv ∪ b.priv
-    metaPub := a.metaPub ∪ b.metaPub
-    metaPriv := a.metaPriv ∪ b.metaPriv }
-
-/-- The list of edits that will be applied in `--fix`. `edits[i] = (removed, added)` where:
-
-* If `j ∈ removed` then we want to delete module named `j` from the imports of `i`
-* If `j ∈ added` then we want to add module index `j` to the imports of `i`.
--/
-abbrev Edits := Std.HashMap Name (Array Import × Array Import)
-
 /-- The main state of the checker, containing information on all loaded modules. -/
 structure State where
   env  : Environment
@@ -220,11 +131,10 @@ structure State where
   `transDeps[i]` is the (non-reflexive) transitive closure of `mods[i].imports`. More specifically,
   * `j ∈ transDeps[i].pub` if `i -(public import)->+ j`
   * `j ∈ transDeps[i].priv` if `i -(import ...)-> _ -(public import)->* j`
-  * `j ∈ transDeps[i].priv` if `i -(import all)->+ i'` and `j ∈ transDeps[i'].pub/priv`
-  * `j ∈ transDeps[i].metaPub` if `i -(public (meta)? import)->* _ -(public meta import)-> _ -(public (meta)? import)->* j`
-  * `j ∈ transDeps[i].metaPriv` if `i -(meta import ...)-> _ -(public (meta)? import)->* j`
-  * `j ∈ transDeps[i].metaPriv` if `i -(import ...)-> i'` and `j ∈ transDeps[i'].metaPub`
-  * `j ∈ transDeps[i].metaPriv` if `i -(import all)->+ i'` and `j ∈ transDeps[i'].metaPub/metaPriv`
+  * `j ∈ transDeps[i].priv` if `i -(import all)->+ -(public import ...)-> _ -(public import)->* j`
+  * `j ∈ transDeps[i].metaPub` if `i -(public (meta)? import)->* _ -(public meta import)-> _ -(public (meta)? import ...)->* j`
+  * `j ∈ transDeps[i].metaPriv` if `i -(meta import ...)-> _ -(public (meta)? import ...)->* j`
+  * `j ∈ transDeps[i].metaPriv` if `i -(import all)->+ -(public meta import ...)-> _ -(public (meta)? import ...)->* j`
   -/
   transDeps : Array Needs := #[]
   /--
@@ -232,10 +142,6 @@ structure State where
   changes to upstream headers.
   -/
   transDepsOrig : Array Needs := #[]
-  /-- Modules that should always be preserved downstream. -/
-  preserve : Needs := default
-  /-- Edits to be applied to the module imports. -/
-  edits : Edits := {}
 
 def State.mods (s : State) := s.env.header.moduleData
 def State.modNames (s : State) := s.env.header.moduleNames
@@ -256,10 +162,10 @@ def addTransitiveImps (transImps : Needs) (imp : Import) (j : Nat) (impTransImps
     -- `j ∈ transDeps[i].priv` if `i -(import ...)-> _ -(public import)->* j`
     transImps := transImps.union .priv {j} |>.union .priv (impTransImps.get .pub)
     if imp.importAll then
-      -- `j ∈ transDeps[i].priv` if `i -(import all)->+ i'` and `j ∈ transDeps[i'].pub/priv`
-      transImps := transImps.union .priv (impTransImps.get .pub ∪ impTransImps.get .priv)
+      -- `j ∈ transDeps[i].priv` if `i -(import all)->+ -(public import ...)-> _ -(public import)->* j`
+      transImps := transImps.union .priv (impTransImps.get .pub)
 
-  -- `j ∈ transDeps[i].metaPub` if `i -(public (meta)? import)->* _ -(public meta import)-> _ -(public (meta)? import)->* j`
+  -- `j ∈ transDeps[i].metaPub` if `i -(public (meta)? import)->* _ -(public meta import)-> _ -(public (meta)? import ...)->* j`
   if imp.isExported then
     transImps := transImps.union .metaPub (impTransImps.get .metaPub)
     if imp.isMeta then
@@ -267,49 +173,20 @@ def addTransitiveImps (transImps : Needs) (imp : Import) (j : Nat) (impTransImps
 
   if !imp.isExported then
     if imp.isMeta then
-      -- `j ∈ transDeps[i].metaPriv` if `i -(meta import ...)-> _ -(public (meta)? import)->* j`
+      -- `j ∈ transDeps[i].metaPriv` if `i -(meta import ...)-> _ -(public (meta)? import ...)->* j`
       transImps := transImps.union .metaPriv {j} |>.union .metaPriv (impTransImps.get .pub ∪ impTransImps.get .metaPub)
     if imp.importAll then
-      -- `j ∈ transDeps[i].metaPriv` if `i -(import all)->+ i'` and `j ∈ transDeps[i'].metaPub/metaPriv`
-      transImps := transImps.union .metaPriv (impTransImps.get .metaPub ∪ impTransImps.get .metaPriv)
-    else
-      -- `j ∈ transDeps[i].metaPriv` if `i -(import ...)-> i'` and `j ∈ transDeps[i'].metaPub`
+      -- `j ∈ transDeps[i].metaPriv` if `i -(import all)->+ -(public meta import ...)-> _ -(public (meta)? import ...)->* j`
       transImps := transImps.union .metaPriv (impTransImps.get .metaPub)
 
   transImps
 
-def isDeclMeta' (env : Environment) (declName : Name) : Bool :=
-  -- Matchers are not compiled by themselves but inlined by the compiler, so there is no IR decl
-  -- to be tagged as `meta`.
-  -- TODO: It would be better to base the entire `meta` inference on the IR only and consider module
-  -- references from any other context as compatible with both phases.
-  let inferFor :=
-    if declName.isStr && (declName.getString!.startsWith "match_" || declName.getString! == "_unsafe_rec") then declName.getPrefix else declName
-  -- `isMarkedMeta` knows about non-defs such as `meta structure`, isDeclMeta knows about decls
-  -- implicitly marked meta
-  isMarkedMeta env inferFor || isDeclMeta env inferFor
-
-/--
-Given an `Expr` reference, returns the declaration name that should be considered the reference, if
-any.
--/
-def getDepConstName? (env : Environment) (ref : Name) : Option Name := do
-  -- Ignore references to reserved names, they can be re-generated in-place
-  guard <| !isReservedName env ref
-  -- `_simp_...` constants are similar, use base decl instead
-  return if ref.isStr && ref.getString!.startsWith "_simp_" then
-    ref.getPrefix
-  else
-    ref
-
 /-- Calculates the needs for a given module `mod` from constants and recorded extra uses. -/
-def calcNeeds (s : State) (i : ModuleIdx) : Needs := Id.run do
-  let env := s.env
+def calcNeeds (env : Environment) (i : ModuleIdx) : Needs := Id.run do
   let mut needs := default
   for ci in env.header.moduleData[i]!.constants do
-    -- Added guard for cases like `structure` that are still exported even if private
-    let pubCI? := guard (!isPrivateName ci.name) *> (env.setExporting true).find? ci.name
-    let k := { isExported := pubCI?.isSome, isMeta := isDeclMeta' env ci.name }
+    let pubCI? := env.setExporting true |>.find? ci.name
+    let k := { isExported := pubCI?.isSome, isMeta := isMeta env ci.name }
     needs := visitExpr k ci.type needs
     if let some e := ci.value? (allowOpaque := true) then
       -- type and value has identical visibility under `meta`
@@ -324,33 +201,23 @@ def calcNeeds (s : State) (i : ModuleIdx) : Needs := Id.run do
   return needs
 where
   /-- Accumulate the results from expression `e` into `deps`. -/
-  visitExpr (k : NeedsKind) (e : Expr) (deps : Needs) : Needs :=
-    let env := s.env
-    Lean.Expr.foldConsts e deps fun c deps => Id.run do
-      let mut deps := deps
-      if let some c := getDepConstName? env c then
-        if let some j := env.getModuleIdxFor? c then
-          let k := { k with isMeta := k.isMeta && !isDeclMeta' env c }
-          if j != i then
-            deps := deps.union k {j}
-            for indMod in (indirectModUseExt.getState env)[c]?.getD #[] do
-              if s.transDeps[i]!.has k indMod then
-                deps := deps.union k {indMod}
-      return deps
-
-abbrev Explanations := Std.HashMap (ModuleIdx × NeedsKind) (Option (Name × Name))
+  visitExpr (k : NeedsKind) e deps :=
+    Lean.Expr.foldConsts e deps fun c deps => match env.getModuleIdxFor? c with
+      | some j =>
+        let k := { k with isMeta := k.isMeta && !isMeta env c }
+        if j != i then deps.union k {j} else deps
+      | _ => deps
 
 /--
 Calculates the same as `calcNeeds` but tracing each module to a use-def declaration pair or
 `none` if merely a recorded extra use.
 -/
-def getExplanations (s : State) (i : ModuleIdx) : Explanations := Id.run do
-  let env := s.env
+def getExplanations (env : Environment) (i : ModuleIdx) :
+    Std.HashMap (ModuleIdx × NeedsKind) (Option (Name × Name)) := Id.run do
   let mut deps := default
   for ci in env.header.moduleData[i]!.constants do
-    -- Added guard for cases like `structure` that are still exported even if private
-    let pubCI? := guard (!isPrivateName ci.name) *> (env.setExporting true).find? ci.name
-    let k := { isExported := pubCI?.isSome, isMeta := isDeclMeta' env ci.name }
+    let pubCI? := env.setExporting true |>.find? ci.name
+    let k := { isExported := pubCI?.isSome, isMeta := isMeta env ci.name }
     deps := visitExpr k ci.name ci.type deps
     if let some e := ci.value? (allowOpaque := true) then
       let k := if k.isMeta then k else
@@ -366,25 +233,18 @@ def getExplanations (s : State) (i : ModuleIdx) : Explanations := Id.run do
 where
   /-- Accumulate the results from expression `e` into `deps`. -/
   visitExpr (k : NeedsKind) name e deps :=
-    let env := s.env
-    Lean.Expr.foldConsts e deps fun c deps => Id.run do
-      let mut deps := deps
-      if let some c := getDepConstName? env c then
-        if let some j := env.getModuleIdxFor? c then
-          let k := { k with isMeta := k.isMeta && !isDeclMeta' env c }
-          deps := addExplanation j k name c deps
-        for indMod in (indirectModUseExt.getState env)[c]?.getD #[] do
-          if s.transDeps[i]!.has k indMod then
-            deps := addExplanation indMod k name (`_indirect ++ c) deps
-      return deps
-  addExplanation (j : ModuleIdx) (k : NeedsKind) (use def_ : Name) (deps : Explanations) : Explanations :=
-    if
-      if let some (some (name', _)) := deps[(j, k)]? then
-        decide (use.toString.length < name'.toString.length)
-      else true
-    then
-      deps.insert (j, k) (use, def_)
-    else deps
+    Lean.Expr.foldConsts e deps fun c deps => match env.getModuleIdxFor? c with
+      | some i =>
+        let k := { k with isMeta := k.isMeta && !isMeta env c }
+        if
+          if let some (some (name', _)) := deps[(i, k)]? then
+            decide (name.toString.length < name'.toString.length)
+          else true
+        then
+          deps.insert (i, k) (name, c)
+        else
+          deps
+      | _ => deps
 
 partial def initStateFromEnv (env : Environment) : State := Id.run do
   let mut s := { env }
@@ -400,6 +260,13 @@ partial def initStateFromEnv (env : Environment) : State := Id.run do
   s := { s with transDepsOrig := s.transDeps }
   return s
 
+/-- The list of edits that will be applied in `--fix`. `edits[i] = (removed, added)` where:
+
+* If `j ∈ removed` then we want to delete module named `j` from the imports of `i`
+* If `j ∈ added` then we want to add module index `j` to the imports of `i`.
+-/
+abbrev Edits := Std.HashMap Name (Array Import × Array Import)
+
 /-- Register that we want to remove `tgt` from the imports of `src`. -/
 def Edits.remove (ed : Edits) (src : Name) (tgt : Import) : Edits :=
   match ed.get? src with
@@ -418,8 +285,8 @@ Returns `(path, inputCtx, imports, endPos)` where `imports` is the `Lean.Parser.
 and `endPos` is the position of the end of the header.
 -/
 def parseHeaderFromString (text path : String) :
-    IO (System.FilePath × (ictx : Parser.InputContext) ×
-      TSyntax ``Parser.Module.header × String.Pos ictx.fileMap.source) := do
+    IO (System.FilePath × Parser.InputContext ×
+      TSyntaxArray ``Parser.Module.import × String.Pos) := do
   let inputCtx := Parser.mkInputContext text path
   let (header, parserState, msgs) ← Parser.parseHeader inputCtx
   if !msgs.toList.isEmpty then -- skip this file if there are parse errors
@@ -427,8 +294,8 @@ def parseHeaderFromString (text path : String) :
     throw <| .userError "parse errors in file"
   -- the insertion point for `add` is the first newline after the imports
   let insertion := header.raw.getTailPos?.getD parserState.pos
-  let insertion := inputCtx.fileMap.source.pos! insertion |>.find (· == '\n') |>.next!
-  pure ⟨path, inputCtx, header, insertion⟩
+  let insertion := text.findAux (· == '\n') text.endPos insertion + ⟨1⟩
+  pure (path, inputCtx, .mk header.raw[2].getArgs, insertion)
 
 /-- Parse a source file to extract the location of the import lines, for edits and error messages.
 
@@ -436,19 +303,14 @@ Returns `(path, inputCtx, imports, endPos)` where `imports` is the `Lean.Parser.
 and `endPos` is the position of the end of the header.
 -/
 def parseHeader (srcSearchPath : SearchPath) (mod : Name) :
-    IO (System.FilePath × (ictx : Parser.InputContext) ×
-      TSyntax ``Parser.Module.header × String.Pos ictx.fileMap.source) := do
+    IO (System.FilePath × Parser.InputContext ×
+      TSyntaxArray ``Parser.Module.import × String.Pos) := do
   -- Parse the input file
   let some path ← srcSearchPath.findModuleWithExt "lean" mod
     | throw <| .userError s!"error: failed to find source file for {mod}"
   let text ← IO.FS.readFile path
   parseHeaderFromString text path.toString
 
-def decodeHeader : TSyntax ``Parser.Module.header → Option (TSyntax `module) × Option (TSyntax `prelude) × TSyntaxArray ``Parser.Module.import
-  | `(Parser.Module.header| $[module%$moduleTk?]? $[prelude%$preludeTk?]? $imports*) =>
-    (moduleTk?.map .mk, preludeTk?.map .mk, imports)
-  | stx => panic! s!"unexpected header syntax {stx}"
-
 def decodeImport : TSyntax ``Parser.Module.import → Import
   | `(Parser.Module.import| $[public%$pubTk?]? $[meta%$metaTk?]? import $[all%$allTk?]? $id) =>
     { module := id.getId, isExported := pubTk?.isSome, isMeta := metaTk?.isSome, importAll := allTk?.isSome }
@@ -456,174 +318,63 @@ def decodeImport : TSyntax ``Parser.Module.import → Import
 
 /-- Analyze and report issues from module `i`. Arguments:
 
-* `pkg`: the first component of the module name
 * `srcSearchPath`: Used to find the path for error reporting purposes
 * `i`: the module index
 * `needs`: the module's calculated needs
+* `pinned`: dependencies that should be preserved even if unused
+* `edits`: accumulates the list of edits to apply if `--fix` is true
 * `addOnly`: if true, only add missing imports, do not remove unused ones
 -/
-def visitModule (pkg : Name) (srcSearchPath : SearchPath)
-    (i : Nat) (needs : Needs) (headerStx : TSyntax ``Parser.Module.header) (args : Args)
-    (addOnly := false) : StateT State IO Unit := do
-  if isExtraRevModUse (← get).env i then
-    modify fun s => { s with preserve := s.preserve.union (if args.addPublic then .pub else .priv) {i} }
-    if args.trace then
-      IO.eprintln s!"Preserving `{(← get).modNames[i]!}` because of recorded extra rev use"
-
-  -- only process modules in the selected package
-  -- TODO: should be after `keep-downstream` but core headers are not found yet?
-  if !pkg.isPrefixOf (← get).modNames[i]! then
-    return
-
-  let (module?, prelude?, imports) := decodeHeader headerStx
-  if module?.any (·.raw.getTrailing?.any (·.toString.contains "shake: keep-downstream")) then
-    modify fun s => { s with preserve := s.preserve.union (if args.addPublic then .pub else .priv) {i} }
-
+def visitModule (srcSearchPath : SearchPath)
+    (i : Nat) (needs : Needs) (preserve : Needs) (edits : Edits)
+    (addOnly := false) (githubStyle := false) (explain := false) : StateT State IO Edits := do
   let s ← get
-
-  let addOnly := addOnly || module?.any (·.raw.getTrailing?.any (·.toString.contains "shake: keep-all"))
+  -- Do transitive reduction of `needs` in `deps`.
   let mut deps := needs
+  for j in [0:s.mods.size] do
+    let transDeps := s.transDeps[j]!
+    for k in NeedsKind.all do
+      if s.transDepsOrig[i]!.has k j && preserve.has k j then
+        deps := deps.union k {j}
+      if deps.has k j then
+        let transDeps := addTransitiveImps .empty { k with module := .anonymous } j transDeps
+        for k' in NeedsKind.all do
+          deps := deps.sub k' (transDeps.sub k' {j} |>.get k')
 
-  -- Add additional preserved imports
-  for impStx in imports do
-    let imp := decodeImport impStx
+  -- Any import which is not in `transDeps` was unused.
+  -- Also accumulate `newDeps` which is the transitive closure of the remaining imports
+  let mut toRemove : Array Import := #[]
+  let mut newDeps := Needs.empty
+  for imp in s.mods[i]!.imports do
     let j := s.env.getModuleIdx? imp.module |>.get!
-    let k := NeedsKind.ofImport imp
-    if addOnly ||
-        args.keepPublic && imp.isExported ||
-        impStx.raw.getTrailing?.any (·.toString.contains "shake: keep") then
-      deps := deps.union k {j}
-      if args.trace then
-        IO.eprintln s!"Adding `{imp}` as additional dependency"
+    if
+        -- skip folder-nested imports
+        s.modNames[i]!.isPrefixOf imp.module ||
+        imp.importAll then
+      newDeps := addTransitiveImps newDeps imp j s.transDeps[j]!
+    else
+      let k := NeedsKind.ofImport imp
+      if !addOnly && !deps.has k j && !deps.has { k with isExported := false } j then
+        toRemove := toRemove.push imp
+      else
+        newDeps := addTransitiveImps newDeps imp j s.transDeps[j]!
+
+  -- If `newDeps` does not cover `deps`, then we have to add back some imports until it does.
+  -- To minimize new imports we pick only new imports which are not transitively implied by
+  -- another new import
+  let mut toAdd : Array Import := #[]
   for j in [0:s.mods.size] do
     for k in NeedsKind.all do
-      -- Remove `meta` while preserving, no use-case for preserving `meta` so far.
-      -- Downgrade to private unless `--add-public` is used.
-      if s.transDepsOrig[i]!.has k j &&
-          (s.preserve.has { k with isMeta := false, isExported := false } j ||
-           s.preserve.has { k with isMeta := false, isExported := true } j) then
-        deps := deps.union { k with isMeta := false, isExported := k.isExported && args.addPublic } {j}
-
-  -- Do transitive reduction of `needs` in `deps`.
-  if !addOnly then
-    for j in [0:s.mods.size] do
-      let transDeps := s.transDeps[j]!
-      for k in NeedsKind.all do
-        if deps.has k j then
-          let transDeps := addTransitiveImps .empty { k with module := .anonymous } j transDeps
-          for k' in NeedsKind.all do
-            deps := deps.sub k' (transDeps.sub k' {j} |>.get k')
-
-  if prelude?.isNone then
-    deps := deps.union .pub {s.env.getModuleIdx? `Init |>.get!}
-
-  -- Accumulate `transDeps` which is the non-reflexive transitive closure of the still-live imports
-  let mut transDeps := Needs.empty
-  let mut alwaysAdd : Array Import := #[]  -- to be added even if implied by other imports
-  for imp in s.mods[i]!.imports do
-    let j := s.env.getModuleIdx? imp.module |>.get!
-    let k := NeedsKind.ofImport imp
-    if deps.has k j || imp.importAll then
-      transDeps := addTransitiveImps transDeps imp j s.transDeps[j]!
-      deps := deps.union k {j}
-    -- skip folder-nested `public (meta)? import`s but remove `meta`
-    else if s.modNames[i]!.isPrefixOf imp.module then
-      let imp := { imp with isMeta := false }
-      let k := { k with isMeta := false }
-      if args.trace then
-        IO.eprintln s!"`{imp}` is preserved as folder-nested import"
-      transDeps := addTransitiveImps transDeps imp j s.transDeps[j]!
-      deps := deps.union k {j}
-      if !s.mods[i]!.imports.contains imp then
-        alwaysAdd := alwaysAdd.push imp
-
-  -- If `transDeps` does not cover `deps`, then we have to add back some imports until it does.
-  -- To minimize new imports we pick only new imports which are not transitively implied by
-  -- another new import, so we visit module indices in descending order.
-  let mut keptPrefix := false
-  let mut newTransDeps := transDeps
-  let mut toAdd : Array Import := #[]
-  for j in (0...s.mods.size).toArray.reverse do
-    for k in NeedsKind.all do
-      if deps.has k j && !newTransDeps.has k j && !newTransDeps.has { k with isExported := true } j then
-        -- `add-public/keep-prefix` may change the import and even module we're considering
-        let mut k := k
-        let mut imp : Import := { k with module := s.modNames[j]! }
-        let mut j := j
-        if args.trace then
-          IO.eprintln s!"`{imp}` is needed{if needs.has k j then " (calculated)" else ""}"
-        if args.addPublic && !k.isExported &&
-            -- also add as public if previously `public meta`, which could be from automatic porting
-            (s.transDepsOrig[i]!.has { k with isExported := true } j || s.transDepsOrig[i]!.has { k with isExported := true, isMeta := true } j) then
-          k := { k with isExported := true }
-          imp := { imp with isExported := true }
-          if args.trace then
-            IO.eprintln s!"* upgrading to `{imp}` because of `--add-public`"
-        if args.keepPrefix then
-          let rec tryPrefix : Name → Option ModuleIdx
-            | .str p _ => tryPrefix p <|> (do
-              let j' ← s.env.getModuleIdx? p
-              -- `j'` must be reachable from `i` (allow downgrading from `meta`)
-              guard <| s.transDepsOrig[i]!.has k j' || s.transDepsOrig[i]!.has { k with isMeta := true } j'
-              let j'transDeps := addTransitiveImps .empty p j' s.transDeps[j']!
-              -- `j` must be reachable from `j'` (now downgrading must be done in the other direction)
-              guard <| j'transDeps.has k j || j'transDeps.has { k with isMeta := false } j
-              return j')
-            | _ => none
-          if let some j' := tryPrefix imp.module then
-            imp := { imp with module := s.modNames[j']! }
-            j := j'
-            keptPrefix := true
-            if args.trace then
-              IO.eprintln s!"* upgrading to `{imp}` because of `--keep-prefix`"
-        if !s.mods[i]!.imports.contains imp then
-          toAdd := toAdd.push imp
-        deps := deps.union k {j}
-        newTransDeps := addTransitiveImps newTransDeps imp j s.transDeps[j]!
-
-  if keptPrefix then
-    -- if an import was replaced by `--keep-prefix`, we did not necessarily visit the modules in
-    -- dependency order anymore and so we have to redo the transitive closure checking
-    newTransDeps := transDeps
-    for j in (0...s.mods.size).toArray.reverse do
-      for k in NeedsKind.all do
-        if deps.has k j then
-          let mut imp : Import := { k with module := s.modNames[j]! }
-          if toAdd.contains imp && (newTransDeps.has k j || newTransDeps.has { k with isExported := true } j) then
-            if args.trace then
-              IO.eprintln s!"Removing `{imp}` from imports to be added because it is now implied"
-            toAdd := toAdd.erase imp
-            deps := deps.sub k {j}
-          else
-            newTransDeps := addTransitiveImps newTransDeps imp j s.transDeps[j]!
-
-  -- now that `toAdd` filtering is done, add `alwaysAdd`
-  toAdd := alwaysAdd ++ toAdd
-
-  -- Any import which is still not in `deps` was unused
-  let mut toRemove : Array Import := #[]
-  for imp in s.mods[i]!.imports do
-    let j := s.env.getModuleIdx? imp.module |>.get!
-    let k := NeedsKind.ofImport imp
-    if args.keepImplied && newTransDeps.has k j then
-      if args.trace && !deps.has k j then
-        IO.eprintln s!"`{imp}` is implied by other imports"
-    else if !deps.has k j then
-      if args.trace then
-        IO.eprintln s!"`{imp}` is now unused"
-      toRemove := toRemove.push imp
-    -- A private import should also be removed if the public version has been added
-    else if !k.isExported && !imp.importAll && newTransDeps.has { k with isExported := true } j then
-      if args.trace then
-        IO.eprintln s!"`{imp}` is already covered by `{ { imp with isExported := true } }`"
-      toRemove := toRemove.push imp
+      if deps.has k j && !newDeps.has k j && !newDeps.has { k with isExported := true } j then
+        let imp := { k with module := s.modNames[j]! }
+        toAdd := toAdd.push imp
+        newDeps := addTransitiveImps newDeps imp j s.transDeps[j]!
 
   -- mark and report the removals
-  modify fun s => { s with
-    edits := toRemove.foldl (init := s.edits) fun edits imp =>
-      edits.remove s.modNames[i]! imp }
+  let mut edits := toRemove.foldl (init := edits) fun edits imp =>
+    edits.remove s.modNames[i]! imp
 
-  if !toAdd.isEmpty || !toRemove.isEmpty || args.explain then
+  if !toAdd.isEmpty || !toRemove.isEmpty || explain then
     if let some path ← srcSearchPath.findModuleWithExt "lean" s.modNames[i]! then
       println! "{path}:"
     else
@@ -632,10 +383,9 @@ def visitModule (pkg : Name) (srcSearchPath : SearchPath)
   if !toRemove.isEmpty then
     println! "  remove {toRemove}"
 
-  if args.githubStyle then
+  if githubStyle then
     try
-      let ⟨path, inputCtx, stx, endHeader⟩ ← parseHeader srcSearchPath s.modNames[i]!
-      let (_, _, imports) := decodeHeader stx
+      let (path, inputCtx, imports, endHeader) ← parseHeader srcSearchPath s.modNames[i]!
       for stx in imports do
         if toRemove.any fun imp => imp == decodeImport stx then
           let pos := inputCtx.fileMap.toPosition stx.raw.getPos?.get!
@@ -643,15 +393,14 @@ def visitModule (pkg : Name) (srcSearchPath : SearchPath)
             (use `lake exe shake --fix` to fix this, or `lake exe shake --update` to ignore)"
       if !toAdd.isEmpty then
         -- we put the insert message on the beginning of the last import line
-        let pos := inputCtx.fileMap.toPosition endHeader.offset
+        let pos := inputCtx.fileMap.toPosition endHeader
         println! "{path}:{pos.line-1}:1: warning: \
           add {toAdd} instead"
     catch _ => pure ()
 
   -- mark and report the additions
-  modify fun s => { s with
-    edits := toAdd.foldl (init := s.edits) fun edits imp =>
-      edits.add s.modNames[i]! imp }
+  edits := toAdd.foldl (init := edits) fun edits imp =>
+    edits.add s.modNames[i]! imp
 
   if !toAdd.isEmpty then
     println! "  add {toAdd}"
@@ -666,15 +415,14 @@ def visitModule (pkg : Name) (srcSearchPath : SearchPath)
     let j := s.env.getModuleIdx? imp.module |>.get!
     newTransDepsI := addTransitiveImps newTransDepsI imp j s.transDeps[j]!
 
-  modify fun s => { s with transDeps := s.transDeps.set! i newTransDepsI }
+  set { s with transDeps := s.transDeps.set! i newTransDepsI }
 
-  if args.explain then
-    let explanation := getExplanations s i
+  if explain then
+    let explanation := getExplanations s.env i
     let sanitize n := if n.hasMacroScopes then (sanitizeName n).run' { options := {} } else n
     let run (imp : Import) := do
       let j := s.env.getModuleIdx? imp.module |>.get!
-      let mut k := NeedsKind.ofImport imp
-      if let some exp? := explanation[(j, k)]? <|> guard args.addPublic *> explanation[(j, { k with isExported := false})]? then
+      if let some exp? := explanation[(j, NeedsKind.ofImport imp)]? then
         println! "  note: `{imp}` required"
         if let some (n, c) := exp? then
           println! "    because `{sanitize n}` refers to `{sanitize c}`"
@@ -685,6 +433,8 @@ def visitModule (pkg : Name) (srcSearchPath : SearchPath)
         run j
     for i in toAdd do run i
 
+  return edits
+
 /-- Convert a list of module names to a bitset of module indexes -/
 def toBitset (s : State) (ns : List Name) : Bitset :=
   ns.foldl (init := ∅) fun c name =>
@@ -692,26 +442,40 @@ def toBitset (s : State) (ns : List Name) : Bitset :=
     | some i => c ∪ {i}
     | none => c
 
+/-- The parsed CLI arguments. See `help` for more information -/
+structure Args where
+  /-- `--help`: shows the help -/
+  help : Bool := false
+  /-- `--force`: skips the `lake build --no-build` sanity check -/
+  force : Bool := false
+  /-- `--gh-style`: output messages that can be parsed by `gh-problem-matcher-wrap` -/
+  githubStyle : Bool := false
+  /-- `--explain`: give constants explaining why each module is needed -/
+  explain : Bool := false
+  /-- `--fix`: apply the fixes directly -/
+  fix : Bool := false
+  /-- `<MODULE>..`: the list of root modules to check -/
+  mods : Array Name := #[]
+
 local instance : Ord Import where
-  compare :=
-    let _ := @lexOrd
-    compareOn fun imp => (!imp.isExported, imp.module.toString)
+  compare a b :=
+    if a.isExported && !b.isExported then
+      Ordering.lt
+    else if !a.isExported && b.isExported then
+      Ordering.gt
+    else
+      a.module.cmp b.module
 
 /-- The main entry point. See `help` for more information on arguments. -/
-public def main (args : List String) : IO UInt32 := do
+def main (args : List String) : IO UInt32 := do
   initSearchPath (← findSysroot)
   -- Parse the arguments
   let rec parseArgs (args : Args) : List String → Args
     | [] => args
     | "--help" :: rest => parseArgs { args with help := true } rest
-    | "--keep-implied" :: rest => parseArgs { args with keepImplied := true } rest
-    | "--keep-prefix" :: rest => parseArgs { args with keepPrefix := true } rest
-    | "--keep-public" :: rest => parseArgs { args with keepPublic := true } rest
-    | "--add-public" :: rest => parseArgs { args with addPublic := true } rest
     | "--force" :: rest => parseArgs { args with force := true } rest
     | "--fix" :: rest => parseArgs { args with fix := true } rest
     | "--explain" :: rest => parseArgs { args with explain := true } rest
-    | "--trace" :: rest => parseArgs { args with trace := true } rest
     | "--gh-style" :: rest => parseArgs { args with githubStyle := true } rest
     | "--" :: rest => { args with mods := args.mods ++ rest.map (·.toName) }
     | other :: rest => parseArgs { args with mods := args.mods.push other.toName } rest
@@ -754,72 +518,62 @@ public def main (args : List String) : IO UInt32 := do
   let imps := mods.map ({ module := · })
   let (_, s) ← importModulesCore imps (isExported := true) |>.run
   let s := s.markAllExported
-  let mut env ← finalizeImport s (isModule := true) imps {} (leakEnv := false) (loadExts := false)
-  -- the one env ext we want to initialize
-  let is := indirectModUseExt.toEnvExtension.getState env
-  let newState ← indirectModUseExt.addImportedFn is.importedEntries { env := env, opts := {} }
-  env := indirectModUseExt.toEnvExtension.setState (asyncMode := .sync) env { is with state := newState }
+  let env ← finalizeImport s (isModule := true) imps {} (leakEnv := false) (loadExts := false)
 
   StateT.run' (s := initStateFromEnv env) do
 
   let s ← get
+  -- Parse the config file
+
   -- Run the calculation of the `needs` array in parallel
   let needs := s.mods.mapIdx fun i _ =>
-    Task.spawn fun _ => calcNeeds s i
-
-  -- Parse headers in parallel
-  let headers ← s.mods.mapIdxM fun i _ =>
-    if !pkg.isPrefixOf s.modNames[i]! then
-      pure <| Task.pure <| .ok ⟨default, default, default, default⟩
-    else
-      BaseIO.asTask (parseHeader srcSearchPath s.modNames[i]! |>.toBaseIO)
+    Task.spawn fun _ => calcNeeds s.env i
 
   if args.fix then
     println! "The following changes will be made automatically:"
 
   -- Check all selected modules
-  for i in [0:s.mods.size], t in needs, header in headers do
-    match header.get with
-    | .ok ⟨_, _, stx, _⟩ =>
-      visitModule pkg srcSearchPath i t.get stx args
-    | .error e =>
-      println! e.toString
+  let mut edits : Edits := ∅
+  let mut revNeeds : Needs := default
+  for i in [0:s.mods.size], t in needs do
+    edits ← visitModule (addOnly := !pkg.isPrefixOf s.modNames[i]!) srcSearchPath i t.get revNeeds edits args.githubStyle args.explain
+    if isExtraRevModUse s.env i then
+      revNeeds := revNeeds.union .priv {i}
 
   if !args.fix then
     -- return error if any issues were found
-    return if (← get).edits.isEmpty then 0 else 1
+    return if edits.isEmpty then 0 else 1
 
   -- Apply the edits to existing files
-  let mut count := 0
-  for mod in s.modNames, header? in headers do
-    let some (remove, add) := (← get).edits[mod]? | continue
+  let count ← edits.foldM (init := 0) fun count mod (remove, add) => do
     let add : Array Import := add.qsortOrd
 
     -- Parse the input file
-    let .ok ⟨path, inputCtx, stx, insertion⟩ := header?.get | continue
-    let (_, _, imports) := decodeHeader stx
+    let (path, inputCtx, imports, insertion) ←
+      try parseHeader srcSearchPath mod
+      catch e => println! e.toString; return count
     let text := inputCtx.fileMap.source
 
     -- Calculate the edit result
-    let mut pos : String.Pos text := text.startPos
+    let mut pos : String.Pos := 0
     let mut out : String := ""
     let mut seen : Std.HashSet Import := {}
     for stx in imports do
       let mod := decodeImport stx
       if remove.contains mod || seen.contains mod then
-        out := out ++ text.extract pos (text.pos! stx.raw.getPos?.get!)
+        out := out ++ text.extract pos stx.raw.getPos?.get!
         -- We use the end position of the syntax, but include whitespace up to the first newline
-        pos := text.pos! stx.raw.getTailPos?.get! |>.find '\n' |>.next!
+        pos := text.findAux (· == '\n') text.rawEndPos stx.raw.getTailPos?.get! + ⟨1⟩
       seen := seen.insert mod
     out := out ++ text.extract pos insertion
     for mod in add do
       if !seen.contains mod then
         seen := seen.insert mod
         out := out ++ s!"{mod}\n"
-    out := out ++ text.extract insertion text.endPos
+    out := out ++ text.extract insertion text.rawEndPos
 
     IO.FS.writeFile path out
-    count := count + 1
+    return count + 1
 
   -- Since we throw an error upon encountering issues, we can be sure that everything worked
   -- if we reach this point of the script.

script/apply.lean

@@ -60,7 +60,7 @@ if (arity == fixed + {n}) \{
   for j in [n:max + 1] do
     let fs := mkFsArgs (j - n)
     let sep := if j = n then "" else ", "
-    emit s!"    case {j}: \{ obj* r = FN{j}(f)({fs}{sep}{args}); lean_free_object(f); return r; }\n"
+    emit s!"    case {j}: \{ obj* r = FN{j}(f)({fs}{sep}{args}); lean_free_small_object(f); return r; }\n"
   emit "    }
   }
   switch (arity) {\n"
@@ -162,7 +162,7 @@ static obj* fix_args(obj* f, unsigned n, obj*const* as) {
       for (unsigned i = 0; i < fixed; i++, source++, target++) {
           *target = *source;
       }
-      lean_free_object(f);
+      lean_free_small_object(f);
     }
     for (unsigned i = 0; i < n; i++, as++, target++) {
         *target = *as;

script/bench.sh

@@ -0,0 +1,96 @@
+#!/usr/bin/env bash
+set -euxo pipefail
+
+cmake --preset release 1>&2
+
+# We benchmark against stage2/bin to test new optimizations.
+timeout -s KILL 1h time make -C build/release -j$(nproc) stage3 1>&2
+export PATH=$PWD/build/release/stage2/bin:$PATH
+
+# The extra opts used to be passed to the Makefile during benchmarking only but with Lake it is
+# easier to configure them statically.
+cmake -B build/release/stage3 -S src -DLEAN_EXTRA_LAKEFILE_TOML='weakLeanArgs=["-Dprofiler=true", "-Dprofiler.threshold=9999999", "--stats"]' 1>&2
+
+(
+cd tests/bench
+timeout -s KILL 1h time temci exec --config speedcenter.yaml --in speedcenter.exec.velcom.yaml 1>&2
+temci report run_output.yaml --reporter codespeed2
+)
+
+if [ -d .git ]; then
+    DIR="$(git rev-parse @)"
+    BASE_URL="https://speed.lean-lang.org/lean4-out/$DIR"
+    {
+        cat <<'EOF'
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="UTF-8">
+  <title>Lakeprof Report</title>
+</head>
+<h1>Lakeprof Report</h1>
+<button type="button" id="btn_fetch">View build trace in Perfetto</button>
+<script type="text/javascript">
+const ORIGIN = 'https://ui.perfetto.dev';
+
+const btnFetch = document.getElementById('btn_fetch');
+
+async function fetchAndOpen(traceUrl) {
+  const resp = await fetch(traceUrl);
+  // Error checking is left as an exercise to the reader.
+  const blob = await resp.blob();
+  const arrayBuffer = await blob.arrayBuffer();
+  openTrace(arrayBuffer, traceUrl);
+}
+
+function openTrace(arrayBuffer, traceUrl) {
+  const win = window.open(ORIGIN);
+  if (!win) {
+    btnFetch.style.background = '#f3ca63';
+  	btnFetch.onclick = () => openTrace(arrayBuffer);
+    btnFetch.innerText = 'Popups blocked, click here to open the trace file';
+    return;
+  }
+
+  const timer = setInterval(() => win.postMessage('PING', ORIGIN), 50);
+
+  const onMessageHandler = (evt) => {
+    if (evt.data !== 'PONG') return;
+
+    // We got a PONG, the UI is ready.
+    window.clearInterval(timer);
+    window.removeEventListener('message', onMessageHandler);
+
+    const reopenUrl = new URL(location.href);
+    reopenUrl.hash = `#reopen=${traceUrl}`;
+    win.postMessage({
+      perfetto: {
+        buffer: arrayBuffer,
+        title: 'Lake Build Trace',
+        url: reopenUrl.toString(),
+    }}, ORIGIN);
+  };
+
+  window.addEventListener('message', onMessageHandler);
+}
+
+// This is triggered when following the link from the Perfetto UI's sidebar.
+if (location.hash.startsWith('#reopen=')) {
+ const traceUrl = location.hash.substr(8);
+ fetchAndOpen(traceUrl);
+}
+EOF
+        cat <<EOF
+btnFetch.onclick = () => fetchAndOpen("$BASE_URL/lakeprof.trace_event");
+</script>
+EOF
+        echo "<pre><code>"
+        (cd src; lakeprof report -prc)
+        echo "</code></pre>"
+        echo "</body></html>"
+    } | tee index.html
+
+    curl -T index.html $BASE_URL/index.html
+    curl -T src/lakeprof.log $BASE_URL/lakeprof.log
+    curl -T src/lakeprof.trace_event $BASE_URL/lakeprof.trace_event
+fi

script/benchReelabRss.lean

@@ -10,16 +10,6 @@ Tests language server memory use by repeatedly re-elaborate a given file.
 NOTE: only works on Linux for now.
 -/
 
-def determineRSS (pid : UInt32) : IO Nat := do
-  let status ← IO.FS.readFile s!"/proc/{pid}/smaps_rollup"
-  let some rssLine := status.splitOn "\n" |>.find? (·.startsWith "Rss:")
-    | throw <| IO.userError "No RSS in proc status"
-  let rssLine := rssLine.dropPrefix "Rss:"
-  let rssLine := rssLine.dropWhile Char.isWhitespace
-  let some rssInKB := rssLine.takeWhile Char.isDigit |>.toNat?
-    | throw <| IO.userError "Cannot parse RSS"
-  return rssInKB
-
 def main (args : List String) : IO Unit := do
   let leanCmd :: file :: iters :: args := args | panic! "usage: script <lean> <file> <#iterations> <server-args>..."
   let file ← IO.FS.realPath file
@@ -44,14 +34,11 @@ def main (args : List String) : IO Unit := do
     let text ← IO.FS.readFile file
     let (_, headerEndPos, _) ← Elab.parseImports text
     let headerEndPos := FileMap.ofString text |>.leanPosToLspPos headerEndPos
-    let n := iters.toNat!
-    let mut lastRSS? : Option Nat := none
-    let mut totalRSSDelta : Int := 0
     let mut requestNo : Nat := 1
     let mut versionNo : Nat := 1
     Ipc.writeNotification ⟨"textDocument/didOpen", {
       textDocument := { uri := uri, languageId := "lean", version := 1, text := text } : DidOpenTextDocumentParams }⟩
-    for i in [0:n] do
+    for i in [0:iters.toNat!] do
       if i > 0 then
         versionNo := versionNo + 1
         let params : DidChangeTextDocumentParams := {
@@ -74,16 +61,9 @@ def main (args : List String) : IO Unit := do
           IO.eprintln diag.message
       requestNo := requestNo + 1
 
-      let rss ← determineRSS (← read).pid
-      -- The first `didChange` usually results in a significantly higher RSS increase than
-      -- the others, so we ignore it.
-      if i > 1 then
-        if let some lastRSS := lastRSS? then
-          totalRSSDelta := totalRSSDelta + ((rss : Int) - (lastRSS : Int))
-      lastRSS? := some rss
-
-    let avgRSSDelta := totalRSSDelta / (n - 2)
-    IO.println s!"avg-reelab-rss-delta: {avgRSSDelta}"
+      let status ← IO.FS.readFile s!"/proc/{(← read).pid}/status"
+      for line in status.splitOn "\n" |>.filter (·.startsWith "RssAnon") do
+        IO.eprintln line
 
     let _ ← Ipc.collectDiagnostics requestNo uri versionNo
     (← Ipc.stdin).writeLspMessage (Message.notification "exit" none)

script/benchReelabWatchdogRss.lean

@@ -1,89 +0,0 @@
-import Lean.Data.Lsp
-import Lean.Elab.Import
-open Lean
-open Lean.Lsp
-open Lean.JsonRpc
-
-/-!
-Tests watchdog memory use by repeatedly re-elaborate a given file.
-
-NOTE: only works on Linux for now.
--/
-
-def determineRSS (pid : UInt32) : IO Nat := do
-  let status ← IO.FS.readFile s!"/proc/{pid}/smaps_rollup"
-  let some rssLine := status.splitOn "\n" |>.find? (·.startsWith "Rss:")
-    | throw <| IO.userError "No RSS in proc status"
-  let rssLine := rssLine.dropPrefix "Rss:"
-  let rssLine := rssLine.dropWhile Char.isWhitespace
-  let some rssInKB := rssLine.takeWhile Char.isDigit |>.toNat?
-    | throw <| IO.userError "Cannot parse RSS"
-  return rssInKB
-
-def main (args : List String) : IO Unit := do
-  let leanCmd :: file :: iters :: args := args | panic! "usage: script <lean> <file> <#iterations> <server-args>..."
-  let file ← IO.FS.realPath file
-  let uri := s!"file://{file}"
-  Ipc.runWith leanCmd (#["--server", "-DstderrAsMessages=false"] ++ args ++ #[uri]) do
-    let capabilities := {
-      textDocument? := some {
-        completion? := some {
-          completionItem? := some {
-            insertReplaceSupport? := true
-          }
-        }
-      }
-    }
-    Ipc.writeRequest ⟨0, "initialize", { capabilities : InitializeParams }⟩
-    discard <| Ipc.readResponseAs 0 InitializeResult
-    Ipc.writeNotification ⟨"initialized", InitializedParams.mk⟩
-
-    let text ← IO.FS.readFile file
-    let (_, headerEndPos, _) ← Elab.parseImports text
-    let headerEndPos := FileMap.ofString text |>.leanPosToLspPos headerEndPos
-    let n := iters.toNat!
-    let mut lastRSS? : Option Nat := none
-    let mut totalRSSDelta : Int := 0
-    let mut requestNo : Nat := 1
-    let mut versionNo : Nat := 1
-    Ipc.writeNotification ⟨"textDocument/didOpen", {
-      textDocument := { uri := uri, languageId := "lean", version := 1, text := text } : DidOpenTextDocumentParams }⟩
-    for i in [0:iters.toNat!] do
-      if i > 0 then
-        versionNo := versionNo + 1
-        let params : DidChangeTextDocumentParams := {
-          textDocument := {
-            uri      := uri
-            version? := versionNo
-          }
-          contentChanges := #[TextDocumentContentChangeEvent.rangeChange {
-            start := headerEndPos
-            «end» := headerEndPos
-          } " "]
-        }
-        let params := toJson params
-        Ipc.writeNotification ⟨"textDocument/didChange", params⟩
-        requestNo := requestNo + 1
-
-      let diags ← Ipc.collectDiagnostics requestNo uri versionNo
-      if let some diags := diags then
-        for diag in diags.param.diagnostics do
-          IO.eprintln diag.message
-      requestNo := requestNo + 1
-
-      Ipc.waitForILeans requestNo uri versionNo
-
-      let rss ← determineRSS (← read).pid
-      -- The first `didChange` usually results in a significantly higher RSS increase than
-      -- the others, so we ignore it.
-      if i > 1 then
-        if let some lastRSS := lastRSS? then
-          totalRSSDelta := totalRSSDelta + ((rss : Int) - (lastRSS : Int))
-      lastRSS? := some rss
-
-    let avgRSSDelta := totalRSSDelta / (n - 2)
-    IO.println s!"avg-reelab-rss-delta: {avgRSSDelta}"
-
-    let _ ← Ipc.collectDiagnostics requestNo uri versionNo
-    Ipc.shutdown requestNo
-    discard <| Ipc.waitForExit

script/build_artifact.py

@@ -1,441 +0,0 @@
-#!/usr/bin/env python3
-"""
-build_artifact.py: Download pre-built CI artifacts for a Lean commit.
-
-Usage:
-    build_artifact.py                     # Download artifact for current HEAD
-    build_artifact.py --sha abc1234       # Download artifact for specific commit
-    build_artifact.py --clear-cache       # Clear artifact cache
-
-This script downloads pre-built binaries from GitHub Actions CI runs,
-which is much faster than building from source (~30s vs 2-5min).
-
-Artifacts are cached in ~/.cache/lean_build_artifact/ for reuse.
-"""
-
-import argparse
-import json
-import os
-import platform
-import shutil
-import subprocess
-import sys
-import urllib.request
-import urllib.error
-from pathlib import Path
-from typing import Optional
-
-# Constants
-GITHUB_API_BASE = "https://api.github.com"
-LEAN4_REPO = "leanprover/lean4"
-
-# CI artifact cache
-CACHE_DIR = Path.home() / '.cache' / 'lean_build_artifact'
-ARTIFACT_CACHE = CACHE_DIR
-
-# Sentinel value indicating CI failed (don't bother building locally)
-CI_FAILED = object()
-
-# ANSI colors for terminal output
-class Colors:
-    RED = '\033[91m'
-    GREEN = '\033[92m'
-    YELLOW = '\033[93m'
-    BLUE = '\033[94m'
-    BOLD = '\033[1m'
-    RESET = '\033[0m'
-
-def color(text: str, c: str) -> str:
-    """Apply color to text if stdout is a tty."""
-    if sys.stdout.isatty():
-        return f"{c}{text}{Colors.RESET}"
-    return text
-
-def error(msg: str) -> None:
-    """Print error message and exit."""
-    print(color(f"Error: {msg}", Colors.RED), file=sys.stderr)
-    sys.exit(1)
-
-def warn(msg: str) -> None:
-    """Print warning message."""
-    print(color(f"Warning: {msg}", Colors.YELLOW), file=sys.stderr)
-
-def info(msg: str) -> None:
-    """Print info message."""
-    print(color(msg, Colors.BLUE), file=sys.stderr)
-
-def success(msg: str) -> None:
-    """Print success message."""
-    print(color(msg, Colors.GREEN), file=sys.stderr)
-
-# -----------------------------------------------------------------------------
-# Platform detection
-# -----------------------------------------------------------------------------
-
-def get_artifact_name() -> Optional[str]:
-    """Get CI artifact name for current platform."""
-    system = platform.system()
-    machine = platform.machine()
-
-    if system == 'Darwin':
-        if machine == 'arm64':
-            return 'build-macOS aarch64'
-        return 'build-macOS'  # Intel
-    elif system == 'Linux':
-        if machine == 'aarch64':
-            return 'build-Linux aarch64'
-        return 'build-Linux release'
-    # Windows not supported for CI artifact download
-    return None
-
-# -----------------------------------------------------------------------------
-# GitHub API helpers
-# -----------------------------------------------------------------------------
-
-_github_token_warning_shown = False
-
-def get_github_token() -> Optional[str]:
-    """Get GitHub token from environment or gh CLI."""
-    global _github_token_warning_shown
-
-    # Check environment variable first
-    token = os.environ.get('GITHUB_TOKEN')
-    if token:
-        return token
-
-    # Try to get token from gh CLI
-    try:
-        result = subprocess.run(
-            ['gh', 'auth', 'token'],
-            capture_output=True,
-            text=True,
-            timeout=5
-        )
-        if result.returncode == 0 and result.stdout.strip():
-            return result.stdout.strip()
-    except (FileNotFoundError, subprocess.TimeoutExpired):
-        pass
-
-    # Warn once if no token available
-    if not _github_token_warning_shown:
-        _github_token_warning_shown = True
-        warn("No GitHub authentication found. API rate limits may apply.")
-        warn("Run 'gh auth login' or set GITHUB_TOKEN to avoid rate limiting.")
-
-    return None
-
-def github_api_request(url: str) -> dict:
-    """Make a GitHub API request and return JSON response."""
-    headers = {
-        'Accept': 'application/vnd.github.v3+json',
-        'User-Agent': 'build-artifact'
-    }
-
-    token = get_github_token()
-    if token:
-        headers['Authorization'] = f'token {token}'
-
-    req = urllib.request.Request(url, headers=headers)
-    try:
-        with urllib.request.urlopen(req, timeout=30) as response:
-            return json.loads(response.read().decode())
-    except urllib.error.HTTPError as e:
-        if e.code == 403:
-            error(f"GitHub API rate limit exceeded. Set GITHUB_TOKEN environment variable to increase limit.")
-        elif e.code == 404:
-            error(f"GitHub resource not found: {url}")
-        else:
-            error(f"GitHub API error: {e.code} {e.reason}")
-    except urllib.error.URLError as e:
-        error(f"Network error accessing GitHub API: {e.reason}")
-
-# -----------------------------------------------------------------------------
-# CI artifact cache functions
-# -----------------------------------------------------------------------------
-
-def get_cache_path(sha: str) -> Path:
-    """Get cache directory for a commit's artifact."""
-    return ARTIFACT_CACHE / sha[:12]
-
-def is_cached(sha: str) -> bool:
-    """Check if artifact for this commit is already cached and valid."""
-    cache_path = get_cache_path(sha)
-    return cache_path.exists() and (cache_path / 'bin' / 'lean').exists()
-
-def check_zstd_support() -> bool:
-    """Check if tar supports zstd compression."""
-    try:
-        result = subprocess.run(
-            ['tar', '--zstd', '--version'],
-            capture_output=True,
-            timeout=5
-        )
-        return result.returncode == 0
-    except (subprocess.TimeoutExpired, FileNotFoundError):
-        return False
-
-def check_gh_available() -> bool:
-    """Check if gh CLI is available and authenticated."""
-    try:
-        result = subprocess.run(
-            ['gh', 'auth', 'status'],
-            capture_output=True,
-            timeout=10
-        )
-        return result.returncode == 0
-    except (subprocess.TimeoutExpired, FileNotFoundError):
-        return False
-
-def download_ci_artifact(sha: str, quiet: bool = False):
-    """
-    Try to download CI artifact for a commit.
-    Returns:
-      - Path to extracted toolchain directory if available
-      - CI_FAILED sentinel if CI run failed (don't bother building locally)
-      - None if no artifact available but local build might work
-    """
-    # Check cache first
-    if is_cached(sha):
-        return get_cache_path(sha)
-
-    artifact_name = get_artifact_name()
-    if artifact_name is None:
-        return None  # Unsupported platform
-
-    cache_path = get_cache_path(sha)
-
-    try:
-        # Query for CI workflow run for this commit, including status
-        # Note: Query parameters must be in the URL for GET requests
-        result = subprocess.run(
-            ['gh', 'api', f'repos/{LEAN4_REPO}/actions/runs?head_sha={sha}&per_page=100',
-             '--jq', r'.workflow_runs[] | select(.name == "CI") | "\(.id) \(.conclusion // "null")"'],
-            capture_output=True,
-            text=True,
-            timeout=30
-        )
-        if result.returncode != 0 or not result.stdout.strip():
-            return None  # No CI run found (old commit?)
-
-        # Parse "run_id conclusion" format
-        line = result.stdout.strip().split('\n')[0]
-        parts = line.split(' ', 1)
-        run_id = parts[0]
-        conclusion = parts[1] if len(parts) > 1 else "null"
-
-        # Check if the desired artifact exists for this run
-        result = subprocess.run(
-            ['gh', 'api', f'repos/{LEAN4_REPO}/actions/runs/{run_id}/artifacts',
-             '--jq', f'.artifacts[] | select(.name == "{artifact_name}") | .id'],
-            capture_output=True,
-            text=True,
-            timeout=30
-        )
-        if result.returncode != 0 or not result.stdout.strip():
-            # No artifact available
-            # If CI failed and no artifact, the build itself likely failed - skip
-            if conclusion == "failure":
-                return CI_FAILED
-            # Otherwise (in progress, expired, etc.) - fall back to local build
-            return None
-
-        # Download artifact
-        cache_path.mkdir(parents=True, exist_ok=True)
-        if not quiet:
-            print("downloading CI artifact... ", end='', flush=True)
-
-        result = subprocess.run(
-            ['gh', 'run', 'download', run_id,
-             '-n', artifact_name,
-             '-R', LEAN4_REPO,
-             '-D', str(cache_path)],
-            capture_output=True,
-            text=True,
-            timeout=600  # 10 minutes for large downloads
-        )
-
-        if result.returncode != 0:
-            shutil.rmtree(cache_path, ignore_errors=True)
-            return None
-
-        # Extract tar.zst - find the file (name varies by platform/version)
-        tar_files = list(cache_path.glob('*.tar.zst'))
-        if not tar_files:
-            shutil.rmtree(cache_path, ignore_errors=True)
-            return None
-
-        tar_file = tar_files[0]
-        if not quiet:
-            print("extracting... ", end='', flush=True)
-
-        result = subprocess.run(
-            ['tar', '--zstd', '-xf', tar_file.name],
-            cwd=cache_path,
-            capture_output=True,
-            timeout=300
-        )
-
-        if result.returncode != 0:
-            shutil.rmtree(cache_path, ignore_errors=True)
-            return None
-
-        # Move contents up from lean-VERSION-PLATFORM/ to cache_path/
-        # The extracted directory name varies (e.g., lean-4.15.0-linux, lean-4.15.0-darwin_aarch64)
-        extracted_dirs = [d for d in cache_path.iterdir() if d.is_dir() and d.name.startswith('lean-')]
-        if extracted_dirs:
-            extracted = extracted_dirs[0]
-            for item in extracted.iterdir():
-                dest = cache_path / item.name
-                if dest.exists():
-                    if dest.is_dir():
-                        shutil.rmtree(dest)
-                    else:
-                        dest.unlink()
-                shutil.move(str(item), str(cache_path / item.name))
-            extracted.rmdir()
-
-        # Clean up tar file
-        tar_file.unlink()
-
-        # Verify the extraction worked
-        if not (cache_path / 'bin' / 'lean').exists():
-            shutil.rmtree(cache_path, ignore_errors=True)
-            return None
-
-        return cache_path
-
-    except (subprocess.TimeoutExpired, FileNotFoundError):
-        shutil.rmtree(cache_path, ignore_errors=True)
-        return None
-
-# -----------------------------------------------------------------------------
-# Git helpers
-# -----------------------------------------------------------------------------
-
-def get_current_commit() -> str:
-    """Get the current git HEAD commit SHA."""
-    try:
-        result = subprocess.run(
-            ['git', 'rev-parse', 'HEAD'],
-            capture_output=True,
-            text=True,
-            timeout=5
-        )
-        if result.returncode == 0:
-            return result.stdout.strip()
-        error(f"Failed to get current commit: {result.stderr.strip()}")
-    except subprocess.TimeoutExpired:
-        error("Timeout getting current commit")
-    except FileNotFoundError:
-        error("git not found")
-
-def resolve_sha(short_sha: str) -> str:
-    """Resolve a (possibly short) SHA to full 40-character SHA using git rev-parse."""
-    if len(short_sha) == 40:
-        return short_sha
-    try:
-        result = subprocess.run(
-            ['git', 'rev-parse', short_sha],
-            capture_output=True,
-            text=True,
-            timeout=5
-        )
-        if result.returncode == 0:
-            full_sha = result.stdout.strip()
-            if len(full_sha) == 40:
-                return full_sha
-        error(f"Cannot resolve SHA '{short_sha}': {result.stderr.strip() or 'not found in repository'}")
-    except subprocess.TimeoutExpired:
-        error(f"Timeout resolving SHA '{short_sha}'")
-    except FileNotFoundError:
-        error("git not found - required for SHA resolution")
-
-# -----------------------------------------------------------------------------
-# Main
-# -----------------------------------------------------------------------------
-
-def main():
-    parser = argparse.ArgumentParser(
-        description='Download pre-built CI artifacts for a Lean commit.',
-        formatter_class=argparse.RawDescriptionHelpFormatter,
-        epilog="""
-This script downloads pre-built binaries from GitHub Actions CI runs,
-which is much faster than building from source (~30s vs 2-5min).
-
-Artifacts are cached in ~/.cache/lean_build_artifact/ for reuse.
-
-Examples:
-  build_artifact.py                   # Download for current HEAD
-  build_artifact.py --sha abc1234     # Download for specific commit
-  build_artifact.py --clear-cache     # Clear cache to free disk space
-"""
-    )
-
-    parser.add_argument('--sha', metavar='SHA',
-                        help='Commit SHA to download artifact for (default: current HEAD)')
-    parser.add_argument('--clear-cache', action='store_true',
-                        help='Clear artifact cache and exit')
-    parser.add_argument('--quiet', '-q', action='store_true',
-                        help='Suppress progress messages (still prints result path)')
-
-    args = parser.parse_args()
-
-    # Handle cache clearing
-    if args.clear_cache:
-        if ARTIFACT_CACHE.exists():
-            size = sum(f.stat().st_size for f in ARTIFACT_CACHE.rglob('*') if f.is_file())
-            shutil.rmtree(ARTIFACT_CACHE)
-            info(f"Cleared cache at {ARTIFACT_CACHE} ({size / 1024 / 1024:.1f} MB)")
-        else:
-            info(f"Cache directory does not exist: {ARTIFACT_CACHE}")
-        return
-
-    # Get commit SHA
-    if args.sha:
-        sha = resolve_sha(args.sha)
-    else:
-        sha = get_current_commit()
-
-    if not args.quiet:
-        info(f"Commit: {sha[:12]}")
-
-    # Check prerequisites
-    if not check_gh_available():
-        error("gh CLI not available or not authenticated. Run 'gh auth login' first.")
-
-    if not check_zstd_support():
-        error("tar does not support zstd compression. Install zstd or a newer tar.")
-
-    artifact_name = get_artifact_name()
-    if artifact_name is None:
-        error(f"No CI artifacts available for this platform ({platform.system()} {platform.machine()})")
-
-    if not args.quiet:
-        info(f"Platform: {artifact_name}")
-
-    # Check cache
-    if is_cached(sha):
-        path = get_cache_path(sha)
-        if not args.quiet:
-            success("Using cached artifact")
-        print(path)
-        return
-
-    # Download artifact
-    result = download_ci_artifact(sha, quiet=args.quiet)
-
-    if result is CI_FAILED:
-        if not args.quiet:
-            print()  # End the "downloading..." line
-        error(f"CI build failed for commit {sha[:12]}")
-    elif result is None:
-        if not args.quiet:
-            print()  # End the "downloading..." line
-        error(f"No CI artifact available for commit {sha[:12]}")
-    else:
-        if not args.quiet:
-            print(color("done", Colors.GREEN))
-        print(result)
-
-if __name__ == '__main__':
-    main()

script/lakefile.toml

@@ -7,5 +7,3 @@ root = "Modulize"
 [[lean_exe]]
 name = "shake"
 root = "Shake"
-# needed by `Lake.loadWorkspace`
-supportInterpreter = true

script/lean-bisect-test.lean

@@ -1,307 +0,0 @@
-/-
-  Copyright Strata Contributors
-
-  SPDX-License-Identifier: Apache-2.0 OR MIT
--/
-
-namespace Strata
-namespace Python
-
-/-
-Parser and translator for some basic regular expression patterns supported by
-Python's `re` library
-Ref.: https://docs.python.org/3/library/re.html
-
-Also see
-https://github.com/python/cpython/blob/759a048d4bea522fda2fe929be0fba1650c62b0e/Lib/re/_parser.py
-for a reference implementation.
--/
-
--------------------------------------------------------------------------------
-
-inductive ParseError where
-  /--
-    `patternError` is raised when Python's `re.patternError` exception is
-    raised.
-    [Reference: Python's re exceptions](https://docs.python.org/3/library/re.html#exceptions):
-
-    "Exception raised when a string passed to one of the functions here is not a
-    valid regular expression (for example, it might contain unmatched
-    parentheses) or when some other error occurs during compilation or matching.
-    It is never an error if a string contains no match for a pattern."
-  -/
-  | patternError  (message : String) (pattern : String) (pos : String.Pos.Raw)
-  /--
-  `unimplemented` is raised whenever we don't support some regex operations
-  (e.g., lookahead assertions).
-  -/
-  | unimplemented (message : String) (pattern : String) (pos : String.Pos.Raw)
-  deriving Repr
-
-def ParseError.toString : ParseError → String
-  | .patternError msg pat pos => s!"Pattern error at position {pos.byteIdx}: {msg} in pattern '{pat}'"
-  | .unimplemented msg pat pos => s!"Unimplemented at position {pos.byteIdx}: {msg} in pattern '{pat}'"
-
-instance : ToString ParseError where
-  toString := ParseError.toString
-
--------------------------------------------------------------------------------
-
-/--
-Regular Expression Nodes
--/
-inductive RegexAST where
-  /-- Single literal character: `a` -/
-  | char : Char → RegexAST
-  /-- Character range: `[a-z]` -/
-  | range : Char → Char → RegexAST
-  /-- Alternation: `a|b` -/
-  | union : RegexAST → RegexAST → RegexAST
-  /-- Concatenation: `ab` -/
-  | concat : RegexAST → RegexAST → RegexAST
-  /-- Any character: `.` -/
-  | anychar : RegexAST
-  /-- Zero or more: `a*` -/
-  | star : RegexAST → RegexAST
-  /-- One or more: `a+` -/
-  | plus : RegexAST → RegexAST
-  /-- Zero or one: `a?` -/
-  | optional : RegexAST → RegexAST
-  /-- Bounded repetition: `a{n,m}` -/
-  | loop : RegexAST → Nat → Nat → RegexAST
-  /-- Start of string: `^` -/
-  | anchor_start : RegexAST
-  /-- End of string: `$` -/
-  | anchor_end : RegexAST
-  /-- Grouping: `(abc)` -/
-  | group : RegexAST → RegexAST
-  /-- Empty string: `()` or `""` -/
-  | empty : RegexAST
-  /-- Complement: `[^a-z]` -/
-  | complement : RegexAST → RegexAST
-  deriving Inhabited, Repr
-
--------------------------------------------------------------------------------
-
-/-- Parse character class like [a-z], [0-9], etc. into union of ranges and
-  chars. Note that this parses `|` as a character. -/
-def parseCharClass (s : String) (pos : String.Pos.Raw) : Except ParseError (RegexAST × String.Pos.Raw) := do
-  if pos.get? s != some '[' then throw (.patternError "Expected '[' at start of character class" s pos)
-  let mut i := pos.next s
-
-  -- Check for complement (negation) with leading ^
-  let isComplement := !i.atEnd s && i.get? s == some '^'
-  if isComplement then
-    i := i.next s
-
-  let mut result : Option RegexAST := none
-
-  -- Process each element in the character class.
-  while !i.atEnd s && i.get? s != some ']' do
-    -- Uncommenting this makes the code stop
-    --dbg_trace "Working" (pure ())
-    let some c1 := i.get? s | throw (.patternError "Invalid character in class" s i)
-    let i1 := i.next s
-    -- Check for range pattern: c1-c2.
-    if !i1.atEnd s && i1.get? s == some '-' then
-      let i2 := i1.next s
-      if !i2.atEnd s && i2.get? s != some ']' then
-        let some c2 := i2.get? s | throw (.patternError "Invalid character in range" s i2)
-        if c1 > c2 then
-          throw (.patternError s!"Invalid character range [{c1}-{c2}]: \
-                                  start character '{c1}' is greater than end character '{c2}'" s i)
-        let r := RegexAST.range c1 c2
-        -- Union with previous elements.
-        result := some (match result with | none => r | some prev => RegexAST.union prev r)
-        i := i2.next s
-        continue
-    -- Single character.
-    let r := RegexAST.char c1
-    result := some (match result with | none => r | some prev => RegexAST.union prev r)
-    i := i.next s
-
-  let some ast := result | throw (.patternError "Unterminated character set" s pos)
-  let finalAst := if isComplement then RegexAST.complement ast else ast
-  pure (finalAst, i.next s)
-
--------------------------------------------------------------------------------
-
-/-- Parse numeric repeats like `{10}` or `{1,10}` into min and max bounds. -/
-def parseBounds (s : String) (pos : String.Pos.Raw) : Except ParseError (Nat × Nat × String.Pos.Raw) := do
-  if pos.get? s != some '{' then throw (.patternError "Expected '{' at start of bounds" s pos)
-  let mut i := pos.next s
-  let mut numStr := ""
-
-  -- Parse first number.
-  while !i.atEnd s && (i.get? s).any Char.isDigit do
-    numStr := numStr.push ((i.get? s).get!)
-    i := i.next s
-
-  let some n := numStr.toNat? | throw (.patternError "Invalid minimum bound" s pos)
-
-  -- Check for comma (range) or closing brace (exact count).
-  match i.get? s with
-  | some '}' => pure (n, n, i.next s)  -- {n} means exactly n times.
-  | some ',' =>
-    i := i.next s
-    -- Parse maximum bound
-    numStr := ""
-    while !i.atEnd s && (i.get? s).any Char.isDigit do
-      numStr := numStr.push ((i.get? s).get!)
-      i := i.next s
-    let some max := numStr.toNat? | throw (.patternError "Invalid maximum bound" s i)
-    if i.get? s != some '}' then throw (.patternError "Expected '}' at end of bounds" s i)
-    -- Validate bounds order
-    if max < n then
-      throw (.patternError s!"Invalid repeat bounds \{{n},{max}}: \
-                              maximum {max} is less than minimum {n}" s pos)
-    pure (n, max, i.next s)
-  | _ => throw (.patternError "Invalid bounds syntax" s i)
-
--------------------------------------------------------------------------------
-
-mutual
-/--
-Parse atom: single element (char, class, anchor, group) with optional
-quantifier. Stops at the first `|`.
--/
-partial def parseAtom (s : String) (pos : String.Pos.Raw) : Except ParseError (RegexAST × String.Pos.Raw) := do
-  if pos.atEnd s then throw (.patternError "Unexpected end of regex" s pos)
-
-  let some c := pos.get? s | throw (.patternError "Invalid position" s pos)
-
-  -- Detect invalid quantifier at start
-  if c == '*' || c == '+' || c == '{' || c == '?' then
-    throw (.patternError s!"Quantifier '{c}' at position {pos} has nothing to quantify" s pos)
-
-  -- Detect unbalanced closing parenthesis
-  if c == ')' then
-    throw (.patternError "Unbalanced parenthesis" s pos)
-
-  -- Parse base element (anchor, char class, group, anychar, escape, or single char).
-  let (base, nextPos) ← match c with
-    | '^' => pure (RegexAST.anchor_start, pos.next s)
-    | '$' => pure (RegexAST.anchor_end, pos.next s)
-    | '[' => parseCharClass s pos
-    | '(' => parseExplicitGroup s pos
-    | '.' => pure (RegexAST.anychar, pos.next s)
-    | '\\' =>
-      -- Handle escape sequence.
-      -- Note: Python uses a single backslash as an escape character, but Lean
-      -- strings need to escape that. After DDMification, we will see two
-      -- backslashes in Strata for every Python backslash.
-      let nextPos := pos.next s
-      if nextPos.atEnd s then throw (.patternError "Incomplete escape sequence at end of regex" s pos)
-      let some escapedChar := nextPos.get? s | throw (.patternError "Invalid escape position" s nextPos)
-      -- Check for special sequences (unsupported right now).
-      match escapedChar with
-      | 'A' | 'b' | 'B' | 'd' | 'D' | 's' | 'S' | 'w' | 'W' | 'z' | 'Z' =>
-        throw (.unimplemented s!"Special sequence \\{escapedChar} is not supported" s pos)
-      | 'a' | 'f' | 'n' | 'N' | 'r' | 't' | 'u' | 'U' | 'v' | 'x' =>
-        throw (.unimplemented s!"Escape sequence \\{escapedChar} is not supported" s pos)
-      | c =>
-        if c.isDigit then
-          throw (.unimplemented s!"Backreference \\{c} is not supported" s pos)
-        else
-          pure (RegexAST.char escapedChar, nextPos.next s)
-    | _ => pure (RegexAST.char c, pos.next s)
-
-  -- Check for numeric repeat suffix on base element (but not on anchors)
-  match base with
-  | .anchor_start | .anchor_end => pure (base, nextPos)
-  | _ =>
-    if !nextPos.atEnd s then
-      match nextPos.get? s with
-      | some '{' =>
-        let (min, max, finalPos) ← parseBounds s nextPos
-        pure (RegexAST.loop base min max, finalPos)
-      | some '*' =>
-        let afterStar := nextPos.next s
-        if !afterStar.atEnd s then
-          match afterStar.get? s with
-          | some '?' => throw (.unimplemented "Non-greedy quantifier *? is not supported" s nextPos)
-          | some '+' => throw (.unimplemented "Possessive quantifier *+ is not supported" s nextPos)
-          | _ => pure (RegexAST.star base, afterStar)
-        else pure (RegexAST.star base, afterStar)
-      | some '+' =>
-        let afterPlus := nextPos.next s
-        if !afterPlus.atEnd s then
-          match afterPlus.get? s with
-          | some '?' => throw (.unimplemented "Non-greedy quantifier +? is not supported" s nextPos)
-          | some '+' => throw (.unimplemented "Possessive quantifier ++ is not supported" s nextPos)
-          | _ => pure (RegexAST.plus base, afterPlus)
-        else pure (RegexAST.plus base, afterPlus)
-      | some '?' =>
-        let afterQuestion := nextPos.next s
-        if !afterQuestion.atEnd s then
-          match afterQuestion.get? s with
-          | some '?' => throw (.unimplemented "Non-greedy quantifier ?? is not supported" s nextPos)
-          | some '+' => throw (.unimplemented "Possessive quantifier ?+ is not supported" s nextPos)
-          | _ => pure (RegexAST.optional base, afterQuestion)
-        else pure (RegexAST.optional base, afterQuestion)
-      | _ => pure (base, nextPos)
-    else
-      pure (base, nextPos)
-
-/-- Parse explicit group with parentheses. -/
-partial def parseExplicitGroup (s : String) (pos : String.Pos.Raw) : Except ParseError (RegexAST × String.Pos.Raw) := do
-  if pos.get? s != some '(' then throw (.patternError "Expected '(' at start of group" s pos)
-  let mut i := pos.next s
-
-  -- Check for extension notation (?...
-  if !i.atEnd s && i.get? s == some '?' then
-    let i1 := i.next s
-    if !i1.atEnd s then
-      match i1.get? s with
-      | some '=' => throw (.unimplemented "Positive lookahead (?=...) is not supported" s pos)
-      | some '!' => throw (.unimplemented "Negative lookahead (?!...) is not supported" s pos)
-      | _ => throw (.unimplemented "Extension notation (?...) is not supported" s pos)
-
-  let (inner, finalPos) ← parseGroup s i (some ')')
-  pure (.group inner, finalPos)
-
-/-- Parse group: handles alternation and concatenation at current scope. -/
-partial def parseGroup (s : String) (pos : String.Pos.Raw) (endChar : Option Char) :
-    Except ParseError (RegexAST × String.Pos.Raw) := do
-  let mut alternatives : List (List RegexAST) := [[]]
-  let mut i := pos
-
-  -- Parse until end of string or `endChar`.
-  while !i.atEnd s && (endChar.isNone || i.get? s != endChar) do
-    if i.get? s == some '|' then
-      -- Push a new scope to `alternatives`.
-      alternatives := [] :: alternatives
-      i := i.next s
-    else
-      let (ast, nextPos) ← parseAtom s i
-      alternatives := match alternatives with
-        | [] => [[ast]]
-        | head :: tail => (ast :: head) :: tail
-      i := nextPos
-
-  -- Check for expected end character.
-  if let some ec := endChar then
-    if i.get? s != some ec then
-      throw (.patternError s!"Expected '{ec}'" s i)
-    i := i.next s
-
-  -- Build result: concatenate each alternative, then union them.
-  let concatAlts := alternatives.reverse.filterMap fun alt =>
-    match alt.reverse with
-    | [] => -- Empty regex.
-      some (.empty)
-    | [single] => some single
-    | head :: tail => some (tail.foldl RegexAST.concat head)
-
-  match concatAlts with
-  | [] => pure (.empty, i)
-  | [single] => pure (single, i)
-  | head :: tail => pure (tail.foldl RegexAST.union head, i)
-end
-
-/-- info: Except.ok (Strata.Python.RegexAST.range 'A' 'z', { byteIdx := 5 }) -/
-#guard_msgs in
-#eval parseCharClass "[A-z]" ⟨0⟩
-
--- Test code: Print done
-#print "Done!"

script/prepare-llvm-linux.sh

@@ -58,11 +58,7 @@ OPTIONS=()
 # We build cadical using the custom toolchain on Linux to avoid glibc versioning issues
 echo -n " -DLEAN_STANDALONE=ON -DCADICAL_USE_CUSTOM_CXX=ON"
 echo -n " -DCMAKE_CXX_COMPILER=$PWD/llvm-host/bin/clang++ -DLEAN_CXX_STDLIB='-Wl,-Bstatic -lc++ -lc++abi -Wl,-Bdynamic'"
-# these should also be used for cadical, so do not use `LEAN_EXTRA_CXX_FLAGS` here
-echo -n " -DCMAKE_CXX_FLAGS='--sysroot $PWD/llvm -idirafter $GLIBC_DEV/include ${EXTRA_FLAGS:-}'"
-# the above does not include linker flags which will be added below based on context, so skip the
-# generic check by cmake
-echo -n " -DCMAKE_C_COMPILER_WORKS=1 -DCMAKE_CXX_COMPILER_WORKS=1"
+echo -n " -DLEAN_EXTRA_CXX_FLAGS='--sysroot $PWD/llvm -idirafter $GLIBC_DEV/include ${EXTRA_FLAGS:-}'"
 # use target compiler directly when not cross-compiling
 if [[ -L llvm-host ]]; then
   echo -n " -DCMAKE_C_COMPILER=$PWD/stage1/bin/clang"

script/release_checklist.py

@@ -31,8 +31,6 @@ What this script does:
    - Ensures tags are merged into stable branches (for non-RC releases)
    - Verifies bump branches exist and are configured correctly
    - Special handling for ProofWidgets4 release tags
-   - For mathlib4: runs verify_version_tags.py to validate the release tag
-     (checks git/GitHub consistency, toolchain, elan, cache, and build)
 
 3. Optionally automates missing steps (when not in --dry-run mode):
    - Creates missing release tags using push_repo_release_tag.py
@@ -501,57 +499,6 @@ def check_proofwidgets4_release(repo_url, target_toolchain, github_token):
     print(f"     You will need to create and push a tag v0.0.{next_version}")
     return False
 
-def run_mathlib_verify_version_tags(toolchain, verbose=False):
-    """Run mathlib4's verify_version_tags.py script to validate the release tag.
-
-    This clones mathlib4 to a temp directory and runs the verification script.
-    Returns True if verification passes, False otherwise.
-    """
-    import tempfile
-
-    print(f"  ... Running mathlib4 verify_version_tags.py {toolchain}")
-
-    with tempfile.TemporaryDirectory() as tmpdir:
-        # Clone mathlib4 (shallow clone is sufficient for running the script)
-        clone_result = subprocess.run(
-            ['git', 'clone', '--depth', '1', 'https://github.com/leanprover-community/mathlib4.git', tmpdir],
-            capture_output=True,
-            text=True
-        )
-        if clone_result.returncode != 0:
-            print(f"  ❌ Failed to clone mathlib4: {clone_result.stderr.strip()[:200]}")
-            return False
-
-        # Run the verification script
-        script_path = os.path.join(tmpdir, 'scripts', 'verify_version_tags.py')
-        if not os.path.exists(script_path):
-            print(f"  ❌ verify_version_tags.py not found in mathlib4 (expected at scripts/verify_version_tags.py)")
-            return False
-
-        # Run from the mathlib4 directory so git operations work
-        result = subprocess.run(
-            ['python3', script_path, toolchain],
-            cwd=tmpdir,
-            capture_output=True,
-            text=True,
-            timeout=900  # 15 minutes timeout for cache download etc.
-        )
-
-        # Print output with indentation
-        if result.stdout:
-            for line in result.stdout.strip().split('\n'):
-                print(f"     {line}")
-        if result.stderr:
-            for line in result.stderr.strip().split('\n'):
-                print(f"     {line}")
-
-        if result.returncode != 0:
-            print(f"  ❌ mathlib4 verify_version_tags.py failed")
-            return False
-
-        print(f"  ✅ mathlib4 verify_version_tags.py passed")
-        return True
-
 def main():
     parser = argparse.ArgumentParser(description="Check release status of Lean4 repositories")
     parser.add_argument("toolchain", help="The toolchain version to check (e.g., v4.6.0)")
@@ -816,12 +763,6 @@ def main():
                 repo_status[name] = False
                 continue
 
-        # For mathlib4, run verify_version_tags.py to validate the release tag
-        if name == "mathlib4":
-            if not run_mathlib_verify_version_tags(toolchain, verbose):
-                repo_status[name] = False
-                continue
-
         repo_status[name] = success
 
     # Final check for lean4 master branch

script/release_repos.yml

@@ -50,26 +50,12 @@ repositories:
     dependencies:
       - lean4-cli
 
-  - name: lean4-unicode-basic
-    url: https://github.com/fgdorais/lean4-unicode-basic
-    toolchain-tag: true
-    stable-branch: false
-    branch: main
-    dependencies: []
-
-  - name: BibtexQuery
-    url: https://github.com/dupuisf/BibtexQuery
-    toolchain-tag: true
-    stable-branch: false
-    branch: master
-    dependencies: [lean4-unicode-basic]
-
   - name: doc-gen4
     url: https://github.com/leanprover/doc-gen4
     toolchain-tag: true
     stable-branch: false
     branch: main
-    dependencies: [lean4-cli, BibtexQuery]
+    dependencies: [lean4-cli]
 
   - name: reference-manual
     url: https://github.com/leanprover/reference-manual
@@ -127,30 +113,10 @@ repositories:
     dependencies:
       - mathlib4
 
-  - name: verso-web-components
-    url: https://github.com/leanprover/verso-web-components
-    toolchain-tag: true
-    stable-branch: false
-    branch: main
-    dependencies:
-      - verso
-
   - name: lean-fro.org
     url: https://github.com/leanprover/lean-fro.org
     toolchain-tag: false
     stable-branch: false
     branch: master
     dependencies:
-      - verso-web-components
-
-  - name: comparator
-    url: https://github.com/leanprover/comparator
-    toolchain-tag: true
-    stable-branch: false
-    branch: master
-
-  - name: lean4export
-    url: https://github.com/leanprover/lean4export
-    toolchain-tag: true
-    stable-branch: false
-    branch: master
+      - verso

script/release_steps.py

@@ -23,7 +23,6 @@ What this script does:
    - Special merging strategies for repositories with nightly-testing branches
    - Safety checks for repositories using bump branches
    - Custom build and test procedures
-   - lean-fro.org: runs scripts/update.sh to regenerate site content
 
 6. Commits the changes with message "chore: bump toolchain to {version}"
 
@@ -413,14 +412,20 @@ def execute_release_steps(repo, version, config):
         run_command("lake update", cwd=repo_path, stream_output=True)
         print(blue("Running `lake update` in examples/hero..."))
         run_command("lake update", cwd=repo_path / "examples" / "hero", stream_output=True)
-
-        # Run scripts/update.sh to regenerate content
-        print(blue("Running `scripts/update.sh` to regenerate content..."))
-        run_command("scripts/update.sh", cwd=repo_path, stream_output=True)
-        print(green("Content regenerated successfully"))
     elif repo_name == "cslib":
         print(blue("Updating lakefile.toml..."))
         run_command(f'perl -pi -e \'s/"v4\\.[0-9]+(\\.[0-9]+)?(-rc[0-9]+)?"/"' + version + '"/g\' lakefile.*', cwd=repo_path)
+        
+        print(blue("Updating docs/lakefile.toml..."))
+        run_command(f'perl -pi -e \'s/"v4\\.[0-9]+(\\.[0-9]+)?(-rc[0-9]+)?"/"' + version + '"/g\' lakefile.*', cwd=repo_path / "docs")
+
+        # Update lean-toolchain in docs
+        print(blue("Updating docs/lean-toolchain..."))
+        docs_toolchain = repo_path / "docs" / "lean-toolchain"
+        with open(docs_toolchain, "w") as f:
+            f.write(f"leanprover/lean4:{version}\n")
+        print(green(f"Updated docs/lean-toolchain to leanprover/lean4:{version}"))
+
         run_command("lake update", cwd=repo_path, stream_output=True)
     elif dependencies:
         run_command(f'perl -pi -e \'s/"v4\\.[0-9]+(\\.[0-9]+)?(-rc[0-9]+)?"/"' + version + '"/g\' lakefile.*', cwd=repo_path)

src/CMakeLists.txt

@@ -10,7 +10,7 @@ endif()
 include(ExternalProject)
 project(LEAN CXX C)
 set(LEAN_VERSION_MAJOR 4)
-set(LEAN_VERSION_MINOR 28)
+set(LEAN_VERSION_MINOR 26)
 set(LEAN_VERSION_PATCH 0)
 set(LEAN_VERSION_IS_RELEASE 0)  # This number is 1 in the release revision, and 0 otherwise.
 set(LEAN_SPECIAL_VERSION_DESC "" CACHE STRING "Additional version description like 'nightly-2018-03-11'")
@@ -42,7 +42,7 @@ if(LLD_PATH)
 endif()
 
 set(LEAN_EXTRA_LINKER_FLAGS ${LEAN_EXTRA_LINKER_FLAGS_DEFAULT} CACHE STRING "Additional flags used by the linker")
-set(LEAN_EXTRA_CXX_FLAGS "" CACHE STRING "Additional flags used by the C++ compiler. Unlike `CMAKE_CXX_FLAGS`, these will not be used to build e.g. cadical.")
+set(LEAN_EXTRA_CXX_FLAGS "" CACHE STRING "Additional flags used by the C++ compiler")
 set(LEAN_TEST_VARS "LEAN_CC=${CMAKE_C_COMPILER}" CACHE STRING "Additional environment variables used when running tests")
 
 if (NOT CMAKE_BUILD_TYPE)
@@ -191,7 +191,7 @@ endif()
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules")
 
 # Initialize CXXFLAGS.
-set(CMAKE_CXX_FLAGS                "${CMAKE_CXX_FLAGS} ${LEAN_EXTRA_CXX_FLAGS} -DLEAN_BUILD_TYPE=\"${CMAKE_BUILD_TYPE}\" -DLEAN_EXPORTING")
+set(CMAKE_CXX_FLAGS                "${LEAN_EXTRA_CXX_FLAGS} -DLEAN_BUILD_TYPE=\"${CMAKE_BUILD_TYPE}\" -DLEAN_EXPORTING")
 set(CMAKE_CXX_FLAGS_DEBUG          "-DLEAN_DEBUG")
 set(CMAKE_CXX_FLAGS_MINSIZEREL     "-DNDEBUG")
 set(CMAKE_CXX_FLAGS_RELEASE        "-DNDEBUG")
@@ -448,8 +448,8 @@ if(LLVM AND ${STAGE} GREATER 0)
     # - In particular, `host/bin/llvm-config` produces flags like `-Lllvm-host/lib/libLLVM`, while
     #   we need the path to be `-Lllvm/lib/libLLVM`. Thus, we perform this replacement here.
     string(REPLACE "llvm-host" "llvm" LEANSHARED_LINKER_FLAGS ${LEANSHARED_LINKER_FLAGS})
-    string(REPLACE "llvm-host" "llvm" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
-    message(VERBOSE "leanshared linker flags: '${LEANSHARED_LINKER_FLAGS}' | lean extra cxx flags '${CMAKE_CXX_FLAGS}'")
+    string(REPLACE "llvm-host" "llvm" LEAN_EXTRA_CXX_FLAGS ${LEAN_EXTRA_CXX_FLAGS})
+    message(VERBOSE "leanshared linker flags: '${LEANSHARED_LINKER_FLAGS}' | lean extra cxx flags '${LEAN_EXTR_CXX_FLAGS}'")
 endif()
 
 # get rid of unused parts of C++ stdlib
@@ -695,7 +695,7 @@ endif()
 
 set(STDLIBS Init Std Lean Leanc)
 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
-  list(APPEND STDLIBS Lake LeanChecker)
+  list(APPEND STDLIBS Lake)
 endif()
 
 add_custom_target(make_stdlib ALL
@@ -758,12 +758,6 @@ if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
     DEPENDS lake_shared
     COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make lake
     VERBATIM)
-
-  add_custom_target(leanchecker ALL
-    WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
-    DEPENDS lake_shared
-    COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make leanchecker
-    VERBATIM)
 endif()
 
 if(PREV_STAGE)

src/Init.lean

@@ -14,8 +14,8 @@ public import Init.ByCases
 public import Init.RCases
 public import Init.Core
 public import Init.Control
+public import Init.Data.Basic
 public import Init.WF
-public import Init.WFComputable
 public import Init.WFTactics
 public import Init.Data
 public import Init.System

src/Init/ByCases.lean

@@ -44,10 +44,3 @@ theorem apply_ite (f : α → β) (P : Prop) [Decidable P] (x y : α) :
 /-- A `dite` whose results do not actually depend on the condition may be reduced to an `ite`. -/
 @[simp] theorem dite_eq_ite [Decidable P] :
   (dite P (fun _ => a) (fun _ => b)) = ite P a b := rfl
-
--- Remark: dite and ite are "defally equal" when we ignore the proofs.
-@[deprecated dite_eq_ite (since := "2025-10-29")]
-theorem dif_eq_if (c : Prop) {h : Decidable c} {α : Sort u} (t : α) (e : α) : dite c (fun _ => t) (fun _ => e) = ite c t e :=
-  match h with
-  | isTrue _    => rfl
-  | isFalse _   => rfl

src/Init/Classical.lean

@@ -102,7 +102,7 @@ noncomputable def strongIndefiniteDescription {α : Sort u} (p : α → Prop) (h
       ⟨xp.val, fun _ => xp.property⟩)
     (fun hp => ⟨choice h, fun h => absurd h hp⟩)
 
-/-- The Hilbert epsilon function. -/
+/-- the Hilbert epsilon Function -/
 noncomputable def epsilon {α : Sort u} [h : Nonempty α] (p : α → Prop) : α :=
   (strongIndefiniteDescription p h).val
 
@@ -181,6 +181,9 @@ theorem not_imp_iff_and_not : ¬(a → b) ↔ a ∧ ¬b := Decidable.not_imp_iff
 
 theorem not_and_iff_not_or_not : ¬(a ∧ b) ↔ ¬a ∨ ¬b := Decidable.not_and_iff_not_or_not
 
+@[deprecated not_and_iff_not_or_not (since := "2025-03-18")]
+abbrev not_and_iff_or_not_not := @not_and_iff_not_or_not
+
 theorem not_iff : ¬(a ↔ b) ↔ (¬a ↔ b) := Decidable.not_iff
 
 @[simp] theorem imp_iff_left_iff  : (b ↔ a → b) ↔ a ∨ b := Decidable.imp_iff_left_iff
@@ -205,5 +208,3 @@ export Classical (imp_iff_right_iff imp_and_neg_imp_iff and_or_imp not_imp)
 
 /-- Show that an element extracted from `P : ∃ a, p a` using `P.choose` satisfies `p`. -/
 theorem Exists.choose_spec {p : α → Prop} (P : ∃ a, p a) : p P.choose := Classical.choose_spec P
-
-grind_pattern Exists.choose_spec => P.choose

src/Init/Coe.lean

@@ -116,7 +116,7 @@ On top of these instances this file defines several auxiliary type classes:
   * `CoeOTC := CoeOut* Coe*`
   * `CoeHTC := CoeHead? CoeOut* Coe*`
   * `CoeHTCT := CoeHead? CoeOut* Coe* CoeTail?`
-  * `CoeT := CoeHead? CoeOut* Coe* CoeTail? | CoeDep`
+  * `CoeDep := CoeHead? CoeOut* Coe* CoeTail? | CoeDep`
 
 -/
 

src/Init/Control.lean

@@ -16,4 +16,3 @@ public import Init.Control.Option
 public import Init.Control.Lawful
 public import Init.Control.StateCps
 public import Init.Control.ExceptCps
-public import Init.Control.MonadAttach

src/Init/Control/Basic.lean

@@ -25,7 +25,7 @@ instances are provided for the same type.
 instance (priority := 500) instForInOfForIn' [ForIn' m ρ α d] : ForIn m ρ α where
   forIn x b f := forIn' x b fun a _ => f a
 
-@[simp] theorem forIn'_eq_forIn [d : Membership α ρ] [ForIn' m ρ α d] {β} (x : ρ) (b : β)
+@[simp] theorem forIn'_eq_forIn [d : Membership α ρ] [ForIn' m ρ α d] {β} [Monad m] (x : ρ) (b : β)
     (f : (a : α) → a ∈ x → β → m (ForInStep β)) (g : (a : α) → β → m (ForInStep β))
     (h : ∀ a m b, f a m b = g a b) :
     forIn' x b f = forIn x b g := by
@@ -40,11 +40,14 @@ instance (priority := 500) instForInOfForIn' [ForIn' m ρ α d] : ForIn m ρ α
   simp [h]
   rfl
 
-@[wf_preprocess] theorem forIn_eq_forIn' [d : Membership α ρ] [ForIn' m ρ α d] {β}
+@[wf_preprocess] theorem forIn_eq_forIn' [d : Membership α ρ] [ForIn' m ρ α d] {β} [Monad m]
     (x : ρ) (b : β) (f : (a : α) → β → m (ForInStep β)) :
     forIn x b f = forIn' x b (fun x h => binderNameHint x f <| binderNameHint h () <| f x) := by
   rfl
 
+@[deprecated forIn_eq_forIn' (since := "2025-04-04")]
+abbrev forIn_eq_forin' := @forIn_eq_forIn'
+
 /--
 Extracts the value from a `ForInStep`, ignoring whether it is `ForInStep.done` or `ForInStep.yield`.
 -/
@@ -144,7 +147,7 @@ instance : ToBool Bool where
 Converts the result of the monadic action `x` to a `Bool`. If it is `true`, returns it and ignores
 `y`; otherwise, runs `y` and returns its result.
 
-This is a monadic counterpart to the short-circuiting `||` operator, usually accessed via the `<||>`
+This a monadic counterpart to the short-circuiting `||` operator, usually accessed via the `<||>`
 operator.
 -/
 @[macro_inline] def orM {m : Type u → Type v} {β : Type u} [Monad m] [ToBool β] (x y : m β) : m β := do
@@ -161,7 +164,7 @@ recommended_spelling "orM" for "<||>" in [orM, «term_<||>_»]
 Converts the result of the monadic action `x` to a `Bool`. If it is `true`, returns `y`; otherwise,
 returns the original result of `x`.
 
-This is a monadic counterpart to the short-circuiting `&&` operator, usually accessed via the `<&&>`
+This a monadic counterpart to the short-circuiting `&&` operator, usually accessed via the `<&&>`
 operator.
 -/
 @[macro_inline] def andM {m : Type u → Type v} {β : Type u} [Monad m] [ToBool β] (x y : m β) : m β := do
@@ -403,7 +406,7 @@ class ForM (m : Type u → Type v) (γ : Type w₁) (α : outParam (Type w₂))
   /--
   Runs the monadic action `f` on each element of the collection `coll`.
   -/
-  forM (coll : γ) (f : α → m PUnit) : m PUnit
+  forM [Monad m] (coll : γ) (f : α → m PUnit) : m PUnit
 
 export ForM (forM)
 

src/Init/Control/EState.lean

@@ -25,12 +25,6 @@ instance [Repr ε] [Repr α] : Repr (Result ε σ α) where
     | Result.error e _, prec => Repr.addAppParen ("EStateM.Result.error " ++ reprArg e) prec
     | Result.ok a _, prec    => Repr.addAppParen ("EStateM.Result.ok " ++ reprArg a) prec
 
-instance : MonadAttach (EStateM ε σ) where
-  CanReturn x a := Exists fun s => Exists fun s' => x.run s = .ok a s'
-  attach x s := match h : x s with
-    | .ok a s' => .ok ⟨a, s, s', h⟩ s'
-    | .error e s' => .error e s'
-
 end EStateM
 
 namespace EStateM

src/Init/Control/Except.lean

@@ -148,23 +148,6 @@ This is the inverse of `ExceptT.mk`.
 @[always_inline, inline, expose]
 def ExceptT.run {ε : Type u} {m : Type u → Type v} {α : Type u} (x : ExceptT ε m α) : m (Except ε α) := x
 
-/--
-Use a monadic action that may throw an exception by providing explicit success and failure
-continuations.
--/
-@[always_inline, inline, expose]
-def ExceptT.runK [Monad m] (x : ExceptT ε m α) (ok : α → m β) (error : ε → m β) : m β :=
-  x.run >>= (·.casesOn error ok)
-
-/--
-Returns the value of a computation, forgetting whether it was an exception or a success.
-
-This corresponds to early return.
--/
-@[always_inline, inline, expose]
-def ExceptT.runCatch [Monad m] (x : ExceptT α m α) : m α :=
-  x.runK pure pure
-
 namespace ExceptT
 
 variable {ε : Type u} {m : Type u → Type v} [Monad m]
@@ -329,8 +312,3 @@ instance ExceptT.finally {m : Type u → Type v} {ε : Type u} [MonadFinally m]
     | (.ok a,    .ok b)    => pure (.ok (a, b))
     | (_,        .error e) => pure (.error e)  -- second error has precedence
     | (.error e, _)        => pure (.error e)
-
-instance [Monad m] [MonadAttach m] : MonadAttach (ExceptT ε m) where
-  CanReturn x a := MonadAttach.CanReturn (m := m) x (.ok a)
-  attach x := show m (Except ε _) from
-      (fun ⟨a, h⟩ => match a with | .ok a => .ok ⟨a, h⟩ | .error e => .error e) <$> MonadAttach.attach (m := m) x

src/Init/Control/ExceptCps.lean

@@ -75,13 +75,6 @@ instance [Monad m] : MonadLift m (ExceptCpsT σ m) where
 instance [Inhabited ε] : Inhabited (ExceptCpsT ε m α) where
   default := fun _ _ k₂ => k₂ default
 
-/--
-For continuation monads, it is not possible to provide a computable `MonadAttach` instance that
-actually adds information about the return value. Therefore, this instance always attaches a proof
-of `True`.
--/
-instance : MonadAttach (ExceptCpsT ε m) := .trivial
-
 @[simp] theorem run_pure [Monad m] : run (pure x : ExceptCpsT ε m α) = pure (Except.ok x) := rfl
 
 @[simp] theorem run_lift {α ε : Type u} [Monad m] (x : m α) : run (ExceptCpsT.lift x : ExceptCpsT ε m α) = (x >>= fun a => pure (Except.ok a) : m (Except ε α)) := rfl

src/Init/Control/Id.lean

@@ -9,7 +9,6 @@ module
 
 prelude
 public import Init.Core
-public import Init.Control.MonadAttach
 
 public section
 
@@ -68,15 +67,4 @@ instance [OfNat α n] : OfNat (Id α) n :=
 instance {m : Type u → Type v} [Pure m] : MonadLiftT Id m where
   monadLift x := pure x.run
 
-instance : MonadAttach Id where
-  CanReturn x a := x.run = a
-  attach x := pure ⟨x.run, rfl⟩
-
-instance : LawfulMonadAttach Id where
-  map_attach := rfl
-  canReturn_map_imp := by
-    intro _ _ x _ h
-    cases h
-    exact x.run.2
-
 end Id

src/Init/Control/Lawful.lean

@@ -10,4 +10,3 @@ public import Init.Control.Lawful.Basic
 public import Init.Control.Lawful.Instances
 public import Init.Control.Lawful.Lemmas
 public import Init.Control.Lawful.MonadLift
-public import Init.Control.Lawful.MonadAttach

src/Init/Control/Lawful/Basic.lean

@@ -170,7 +170,6 @@ theorem bind_pure_unit [Monad m] [LawfulMonad m] {x : m PUnit} : (x >>= fun _ =>
 theorem map_congr [Functor m] {x : m α} {f g : α → β} (h : ∀ a, f a = g a) : (f <$> x : m β) = g <$> x := by
   simp [funext h]
 
-@[deprecated seq_eq_bind_map (since := "2025-10-26")]
 theorem seq_eq_bind {α β : Type u} [Monad m] [LawfulMonad m] (mf : m (α → β)) (x : m α) : mf <*> x = mf >>= fun f => f <$> x := by
   rw [bind_map]
 
@@ -248,12 +247,28 @@ namespace Id
 instance : LawfulMonad Id := by
   refine LawfulMonad.mk' _ ?_ ?_ ?_ <;> intros <;> rfl
 
-@[simp, grind =] theorem run_map (x : Id α) (f : α → β) : (f <$> x).run = f x.run := rfl
-@[simp, grind =] theorem run_bind (x : Id α) (f : α → Id β) : (x >>= f).run = (f x.run).run := rfl
-@[simp, grind =] theorem run_pure (a : α) : (pure a : Id α).run = a := rfl
-@[simp, grind =] theorem pure_run (a : Id α) : pure a.run = a := rfl
+@[simp] theorem run_map (x : Id α) (f : α → β) : (f <$> x).run = f x.run := rfl
+@[simp] theorem run_bind (x : Id α) (f : α → Id β) : (x >>= f).run = (f x.run).run := rfl
+@[simp] theorem run_pure (a : α) : (pure a : Id α).run = a := rfl
+@[simp] theorem pure_run (a : Id α) : pure a.run = a := rfl
 @[simp] theorem run_seqRight (x y : Id α) : (x *> y).run = y.run := rfl
 @[simp] theorem run_seqLeft (x y : Id α) : (x <* y).run = x.run := rfl
 @[simp] theorem run_seq (f : Id (α → β)) (x : Id α) : (f <*> x).run = f.run x.run := rfl
 
+-- These lemmas are bad as they abuse the defeq of `Id α` and `α`
+@[deprecated run_map (since := "2025-03-05")] theorem map_eq (x : Id α) (f : α → β) : f <$> x = f x := rfl
+@[deprecated run_bind (since := "2025-03-05")] theorem bind_eq (x : Id α) (f : α → id β) : x >>= f = f x := rfl
+@[deprecated run_pure (since := "2025-03-05")] theorem pure_eq (a : α) : (pure a : Id α) = a := rfl
+
 end Id
+
+/-! # Option -/
+
+instance : LawfulMonad Option := LawfulMonad.mk'
+  (id_map := fun x => by cases x <;> rfl)
+  (pure_bind := fun _ _ => rfl)
+  (bind_assoc := fun x _ _ => by cases x <;> rfl)
+  (bind_pure_comp := fun _ x => by cases x <;> rfl)
+
+instance : LawfulApplicative Option := inferInstance
+instance : LawfulFunctor Option := inferInstance

src/Init/Control/Lawful/Instances.lean

@@ -17,9 +17,6 @@ public section
 
 open Function
 
-@[simp, grind =] theorem monadMap_refl {m : Type _ → Type _} {α} (f : ∀ {α}, m α → m α) :
-    monadMap @f = @f α := rfl
-
 /-! # ExceptT -/
 
 namespace ExceptT
@@ -28,8 +25,6 @@ namespace ExceptT
   simp [run] at h
   assumption
 
-@[simp, grind =] theorem run_mk (x : m (Except ε α)) : run (mk x : ExceptT ε m α) = x := rfl
-
 @[simp, grind =] theorem run_pure [Monad m] (x : α) : run (pure x : ExceptT ε m α) = pure (Except.ok x) := rfl
 
 @[simp, grind =] theorem run_lift  [Monad.{u, v} m] (x : m α) : run (ExceptT.lift x : ExceptT ε m α) = (Except.ok <$> x : m (Except ε α)) := rfl
@@ -60,9 +55,6 @@ theorem run_bind [Monad m] (x : ExceptT ε m α) (f : α → ExceptT ε m β)
   apply bind_congr
   intro a; cases a <;> simp [Except.map]
 
-@[simp, grind =] theorem run_monadMap [MonadFunctorT n m] (f : {β : Type u} → n β → n β) (x : ExceptT ε m α)
-    : (monadMap @f x : ExceptT ε m α).run = monadMap @f (x.run) := rfl
-
 protected theorem seq_eq {α β ε : Type u} [Monad m] (mf : ExceptT ε m (α → β)) (x : ExceptT ε m α) : mf <*> x = mf >>= fun f => f <$> x :=
   rfl
 
@@ -105,22 +97,6 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (ExceptT ε m) where
   simp only [ExceptT.instMonad, ExceptT.map, ExceptT.mk, throw, throwThe, MonadExceptOf.throw,
     pure_bind]
 
-/-! Note that the `MonadControl` instance for `ExceptT` is not monad-generic. -/
-
-@[simp] theorem run_restoreM [Monad m] (x : stM m (ExceptT ε m) α) :
-    ExceptT.run (restoreM x) = pure x := rfl
-
-@[simp] theorem run_liftWith [Monad m] (f : ({β : Type u} → ExceptT ε m β → m (stM m (ExceptT ε m) β)) → m α) :
-    ExceptT.run (liftWith f) = Except.ok <$> (f fun x => x.run) :=
-  rfl
-
-@[simp] theorem run_controlAt [Monad m] [LawfulMonad m] (f : ({β : Type u} → ExceptT ε m β → m (stM m (ExceptT ε m) β)) → m (stM m (ExceptT ε m) α)) :
-    ExceptT.run (controlAt m f) = f fun x => x.run := by
-  simp [controlAt, run_bind, bind_map_left]
-
-@[simp] theorem run_control [Monad m] [LawfulMonad m] (f : ({β : Type u} → ExceptT ε m β → m (stM m (ExceptT ε m) β)) → m (stM m (ExceptT ε m) α)) :
-    ExceptT.run (control f) = f fun x => x.run := run_controlAt f
-
 end ExceptT
 
 /-! # Except -/
@@ -174,9 +150,6 @@ namespace OptionT
   apply bind_congr
   intro a; cases a <;> simp [OptionT.pure, OptionT.mk]
 
-@[simp, grind =] theorem run_monadMap [MonadFunctorT n m] (f : {β : Type u} → n β → n β) (x : OptionT m α)
-    : (monadMap @f x : OptionT m α).run = monadMap @f (x.run) := rfl
-
 protected theorem seq_eq {α β : Type u} [Monad m] (mf : OptionT m (α → β)) (x : OptionT m α) : mf <*> x = mf >>= fun f => f <$> x :=
   rfl
 
@@ -216,12 +189,12 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (OptionT m) where
 
 @[simp] theorem run_seq [Monad m] [LawfulMonad m] (f : OptionT m (α → β)) (x : OptionT m α) :
     (f <*> x).run = Option.elimM f.run (pure none) (fun f => Option.map f <$> x.run) := by
-  simp [seq_eq_bind_map, Option.elimM, Option.elim]
+  simp [seq_eq_bind, Option.elimM, Option.elim]
 
 @[simp] theorem run_seqLeft [Monad m] [LawfulMonad m] (x : OptionT m α) (y : OptionT m β) :
     (x <* y).run = Option.elimM x.run (pure none)
       (fun x => Option.map (Function.const β x) <$> y.run) := by
-  simp [seqLeft_eq, seq_eq_bind_map, Option.elimM, OptionT.run_bind]
+  simp [seqLeft_eq, seq_eq_bind, Option.elimM, OptionT.run_bind]
 
 @[simp] theorem run_seqRight [Monad m] [LawfulMonad m] (x : OptionT m α) (y : OptionT m β) :
     (x *> y).run = Option.elimM x.run (pure none) (Function.const α y.run) := by
@@ -238,24 +211,6 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (OptionT m) where
     (x <|> y).run = Option.elimM x.run y.run (fun x => pure (some x)) :=
   bind_congr fun | some _ => by rfl | none => by rfl
 
-/-! Note that the `MonadControl` instance for `OptionT` is not monad-generic. -/
-
-@[simp] theorem run_restoreM [Monad m] (x : stM m (OptionT m) α) :
-    OptionT.run (restoreM x) = pure x := rfl
-
-@[simp] theorem run_liftWith [Monad m] [LawfulMonad m] (f : ({β : Type u} → OptionT m β → m (stM m (OptionT m) β)) → m α) :
-    OptionT.run (liftWith f) = Option.some <$> (f fun x => x.run) := by
-  dsimp [liftWith]
-  rw [← bind_pure_comp]
-  rfl
-
-@[simp] theorem run_controlAt [Monad m] [LawfulMonad m] (f : ({β : Type u} → OptionT m β → m (stM m (OptionT m) β)) → m (stM m (OptionT m) α)) :
-    OptionT.run (controlAt m f) = f fun x => x.run := by
-  simp [controlAt, Option.elimM, Option.elim]
-
-@[simp] theorem run_control [Monad m] [LawfulMonad m] (f : ({β : Type u} → OptionT m β → m (stM m (OptionT m) β)) → m (stM m (OptionT m) α)) :
-    OptionT.run (control f) = f fun x => x.run := run_controlAt f
-
 end OptionT
 
 /-! # Option -/
@@ -264,7 +219,7 @@ instance : LawfulMonad Option := LawfulMonad.mk'
   (id_map := fun x => by cases x <;> rfl)
   (pure_bind := fun _ _ => by rfl)
   (bind_assoc := fun a _ _ => by cases a <;> rfl)
-  (bind_pure_comp := fun _ x => by cases x <;> rfl)
+  (bind_pure_comp := bind_pure_comp)
 
 instance : LawfulApplicative Option := inferInstance
 instance : LawfulFunctor Option := inferInstance
@@ -277,9 +232,6 @@ namespace ReaderT
   simp [run] at h
   exact funext h
 
-@[simp, grind =] theorem run_mk (x : ρ → m α) (ctx : ρ) : run (.mk x : ReaderT ρ m α) ctx = x ctx :=
-  rfl
-
 @[simp, grind =] theorem run_pure [Monad m] (a : α) (ctx : ρ) : (pure a : ReaderT ρ m α).run ctx = pure a := rfl
 
 @[simp, grind =] theorem run_bind [Monad m] (x : ReaderT ρ m α) (f : α → ReaderT ρ m β) (ctx : ρ)
@@ -327,22 +279,6 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (ReaderT ρ m) where
   pure_bind      := by intros; apply ext; intros; simp
   bind_assoc     := by intros; apply ext; intros; simp
 
-/-! Note that the `MonadControl` instance for `ReaderT` is not monad-generic. -/
-
-@[simp] theorem run_restoreM [Monad m] (x : stM m (ReaderT ρ m) α) (ctx : ρ) :
-    ReaderT.run (restoreM x) ctx = pure x := rfl
-
-@[simp] theorem run_liftWith [Monad m] (f : ({β : Type u} → ReaderT ρ m β → m (stM m (ReaderT ρ m) β)) → m α) (ctx : ρ) :
-    ReaderT.run (liftWith f) ctx = (f fun x => x.run ctx) :=
-  rfl
-
-@[simp] theorem run_controlAt [Monad m] [LawfulMonad m] (f : ({β : Type u} → ReaderT ρ m β → m (stM m (ReaderT ρ m) β)) → m (stM m (ReaderT ρ m) α)) (ctx : ρ) :
-    ReaderT.run (controlAt m f) ctx = f fun x => x.run ctx := by
-  simp [controlAt]
-
-@[simp] theorem run_control [Monad m] [LawfulMonad m] (f : ({β : Type u} → ReaderT ρ m β → m (stM m (ReaderT ρ m) β)) → m (stM m (ReaderT ρ m) α)) (ctx : ρ) :
-    ReaderT.run (control f) ctx = f fun x => x.run ctx := run_controlAt f ctx
-
 end ReaderT
 
 /-! # StateRefT -/
@@ -357,20 +293,17 @@ namespace StateT
 @[ext, grind ext] theorem ext {x y : StateT σ m α} (h : ∀ s, x.run s = y.run s) : x = y :=
   funext h
 
-@[simp, grind =] theorem run_mk [Monad m] (x : σ → m (α × σ)) (s : σ) : run (.mk x) s = x s :=
-  rfl
-
 @[simp, grind =] theorem run'_eq [Monad m] (x : StateT σ m α) (s : σ) : run' x s = (·.1) <$> run x s :=
   rfl
 
 @[simp, grind =] theorem run_pure [Monad m] (a : α) (s : σ) : (pure a : StateT σ m α).run s = pure (a, s) := rfl
 
 @[simp, grind =] theorem run_bind [Monad m] (x : StateT σ m α) (f : α → StateT σ m β) (s : σ)
-    : (x >>= f).run s = x.run s >>= λ p => (f p.1).run p.2 := rfl
+    : (x >>= f).run s = x.run s >>= λ p => (f p.1).run p.2 := by
+  simp [bind, StateT.bind, run]
 
 @[simp, grind =] theorem run_map {α β σ : Type u} [Monad m] [LawfulMonad m] (f : α → β) (x : StateT σ m α) (s : σ) : (f <$> x).run s = (fun (p : α × σ) => (f p.1, p.2)) <$> x.run s := by
-  rw [← bind_pure_comp (m := m)]
-  rfl
+  simp [Functor.map, StateT.map, run, ←bind_pure_comp]
 
 @[simp, grind =] theorem run_get [Monad m] (s : σ)    : (get : StateT σ m σ).run s = pure (s, s) := rfl
 
@@ -379,13 +312,13 @@ namespace StateT
 @[simp, grind =] theorem run_modify [Monad m] (f : σ → σ) (s : σ) : (modify f : StateT σ m PUnit).run s = pure (⟨⟩, f s) := rfl
 
 @[simp, grind =] theorem run_modifyGet [Monad m] (f : σ → α × σ) (s : σ) : (modifyGet f : StateT σ m α).run s = pure ((f s).1, (f s).2) := by
-  rfl
+  simp [modifyGet, MonadStateOf.modifyGet, StateT.modifyGet, run]
 
 @[simp, grind =] theorem run_lift {α σ : Type u} [Monad m] (x : m α) (s : σ) : (StateT.lift x : StateT σ m α).run s = x >>= fun a => pure (a, s) := rfl
 
 @[grind =]
 theorem run_bind_lift {α σ : Type u} [Monad m] [LawfulMonad m] (x : m α) (f : α → StateT σ m β) (s : σ) : (StateT.lift x >>= f).run s = x >>= fun a => (f a).run s := by
-  simp
+  simp [StateT.lift, StateT.run, bind, StateT.bind]
 
 @[simp, grind =] theorem run_monadLift {α σ : Type u} [Monad m] [MonadLiftT n m] (x : n α) (s : σ) : (monadLift x : StateT σ m α).run s = (monadLift x : m α) >>= fun a => pure (a, s) := rfl
 
@@ -425,48 +358,10 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (StateT σ m) where
   pure_bind      := by intros; apply ext; intros; simp
   bind_assoc     := by intros; apply ext; intros; simp
 
-/-! Note that the `MonadControl` instance for `StateT` is not monad-generic. -/
-
-@[simp] theorem run_restoreM [Monad m] [LawfulMonad m] (x : stM m (StateT σ m) α) (s : σ) :
-    StateT.run (restoreM x) s = pure x := by
-  simp [restoreM, MonadControl.restoreM]
-  rfl
-
-@[simp] theorem run_liftWith [Monad m] [LawfulMonad m] (f : ({β : Type u} → StateT σ m β → m (stM m (StateT σ m) β)) → m α) (s : σ) :
-    StateT.run (liftWith f) s = ((·, s) <$> f fun x => x.run s) := by
-  simp [liftWith, MonadControl.liftWith, Function.comp_def]
-
-@[simp] theorem run_controlAt [Monad m] [LawfulMonad m] (f : ({β : Type u} → StateT σ m β → m (stM m (StateT σ m) β)) → m (stM m (StateT σ m) α)) (s : σ) :
-    StateT.run (controlAt m f) s = f fun x => x.run s := by
-  simp [controlAt]
-
-@[simp] theorem run_control [Monad m] [LawfulMonad m] (f : ({β : Type u} → StateT σ m β → m (stM m (StateT σ m) β)) → m (stM m (StateT σ m) α)) (s : σ) :
-    StateT.run (control f) s = f fun x => x.run s := run_controlAt f s
-
 end StateT
 
 /-! # EStateM -/
 
-namespace EStateM
-
-@[simp, grind =] theorem run_pure (a : α) (s : σ) :
-    EStateM.run (pure a : EStateM ε σ α) s = .ok a s := rfl
-
-@[simp, grind =] theorem run_get (s : σ) :
-    EStateM.run (get : EStateM ε σ σ) s = .ok s s := rfl
-
-@[simp, grind =] theorem run_set (s₁ s₂ : σ) :
-    EStateM.run (set s₁ : EStateM ε σ PUnit) s₂ = .ok .unit s₁ := rfl
-
-@[simp, grind =] theorem run_modify (f : σ → σ) (s : σ) :
-    EStateM.run (modify f : EStateM ε σ PUnit) s = .ok .unit (f s) := rfl
-
-@[simp, grind =] theorem run_modifyGet (f : σ → α × σ) (s : σ) :
-    EStateM.run (modifyGet f : EStateM ε σ α) s = .ok (f s).1 (f s).2 := rfl
-
-@[simp, grind =] theorem run_throw (e : ε) (s : σ):
-    EStateM.run (throw e : EStateM ε σ PUnit) s = .error e s := rfl
-
 instance : LawfulMonad (EStateM ε σ) := .mk'
   (id_map := fun x => funext <| fun s => by
     dsimp only [EStateM.instMonad, EStateM.map]
@@ -480,5 +375,3 @@ instance : LawfulMonad (EStateM ε σ) := .mk'
     | .ok _ _ => rfl
     | .error _ _ => rfl)
   (map_const := fun _ _ => rfl)
-
-end EStateM

src/Init/Control/Lawful/MonadAttach.lean

@@ -1,10 +0,0 @@
-/-
-Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Paul Reichert
--/
-module
-
-prelude
-public import Init.Control.Lawful.MonadAttach.Lemmas
-public import Init.Control.Lawful.MonadAttach.Instances

src/Init/Control/Lawful/MonadAttach/Instances.lean

@@ -1,86 +0,0 @@
-/-
-Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Paul Reichert
--/
-module
-
-prelude
-public import Init.Control.Reader
-public import Init.Control.Lawful.Instances
-import Init.Control.Lawful.MonadAttach.Lemmas
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [WeaklyLawfulMonadAttach m] :
-    WeaklyLawfulMonadAttach (ReaderT ρ m) where
-  map_attach := by
-    simp only [Functor.map, MonadAttach.attach, Functor.map_map, WeaklyLawfulMonadAttach.map_attach]
-    intros; rfl
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [LawfulMonadAttach m] :
-    LawfulMonadAttach (ReaderT ρ m) where
-  canReturn_map_imp := by
-    simp only [Functor.map, MonadAttach.CanReturn, ReaderT.run]
-    rintro _ _ x a ⟨r, h⟩
-    apply LawfulMonadAttach.canReturn_map_imp h
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [WeaklyLawfulMonadAttach m] :
-    WeaklyLawfulMonadAttach (StateT σ m) where
-  map_attach := by
-    intro α x
-    simp only [Functor.map, StateT, funext_iff, StateT.map, bind_pure_comp, MonadAttach.attach,
-      Functor.map_map]
-    exact fun s => WeaklyLawfulMonadAttach.map_attach
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [LawfulMonadAttach m] :
-    LawfulMonadAttach (StateT σ m) where
-  canReturn_map_imp := by
-    simp only [Functor.map, MonadAttach.CanReturn, StateT.run, StateT.map, bind_pure_comp]
-    rintro _ _ x a ⟨s, s', h⟩
-    obtain ⟨a, h, h'⟩ := LawfulMonadAttach.canReturn_map_imp' h
-    cases h'
-    exact a.1.2
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [WeaklyLawfulMonadAttach m] :
-    WeaklyLawfulMonadAttach (ExceptT ε m) where
-  map_attach {α} x := by
-    simp only [Functor.map, MonadAttach.attach, ExceptT.map]
-    simp
-    conv => rhs; rw [← WeaklyLawfulMonadAttach.map_attach (m := m) (x := x)]
-    simp only [map_eq_pure_bind]
-    apply bind_congr; intro a
-    match a with
-    | ⟨.ok _, _⟩ => simp
-    | ⟨.error _, _⟩ => simp
-
-public instance [Monad m] [LawfulMonad m] [MonadAttach m] [LawfulMonadAttach m] :
-    LawfulMonadAttach (ExceptT ε m) where
-  canReturn_map_imp {α P x a} := by
-    simp only [Functor.map, MonadAttach.CanReturn, ExceptT.map, ExceptT.mk]
-    let x' := (fun a => show Subtype (fun a : Except _ _ => match a with | .ok a => P a | .error e => True) from ⟨match a with | .ok a => .ok a.1 | .error e => .error e, by cases a <;> simp [Subtype.property]⟩) <$> show m _ from x
-    have := LawfulMonadAttach.canReturn_map_imp (m := m) (x := x') (a := .ok a)
-    simp only at this
-    intro h
-    apply this
-    simp only [x', map_eq_pure_bind, bind_assoc]
-    refine cast ?_ h
-    congr 1
-    apply bind_congr; intro a
-    split <;> simp
-
-public instance [Monad m] [MonadAttach m] [LawfulMonad m] [WeaklyLawfulMonadAttach m] :
-    WeaklyLawfulMonadAttach (StateRefT' ω σ m) :=
-  inferInstanceAs (WeaklyLawfulMonadAttach (ReaderT _ _))
-
-public instance [Monad m] [MonadAttach m] [LawfulMonad m] [LawfulMonadAttach m] :
-    LawfulMonadAttach (StateRefT' ω σ m) :=
-  inferInstanceAs (LawfulMonadAttach (ReaderT _ _))
-
-section
-
-attribute [local instance] MonadAttach.trivial
-
-public instance [Monad m] [LawfulMonad m] :
-    WeaklyLawfulMonadAttach m where
-  map_attach := by simp [MonadAttach.attach]
-
-end

src/Init/Control/Lawful/MonadAttach/Lemmas.lean

@@ -1,90 +0,0 @@
-/-
-Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Paul Reichert
--/
-module
-
-prelude
-public import Init.Control.MonadAttach
-import all Init.Control.MonadAttach
-public import Init.Control.Lawful.Lemmas
-public import Init.Control.Lawful.MonadLift.Lemmas
-
-public theorem LawfulMonadAttach.canReturn_bind_imp' [Monad m] [LawfulMonad m]
-    [MonadAttach m] [LawfulMonadAttach m]
-    {x : m α} {f : α → m β} :
-    MonadAttach.CanReturn (x >>= f) b → Exists fun a => MonadAttach.CanReturn x a ∧ MonadAttach.CanReturn (f a) b := by
-  intro h
-  let P (b : β) := Exists fun a => MonadAttach.CanReturn x a ∧ MonadAttach.CanReturn (f a) b
-  have h' : (x >>= f) = Subtype.val <$> (MonadAttach.attach x >>= (fun a => (do
-      let b ← MonadAttach.attach (f a)
-      return ⟨b.1, a.1, a.2, b.2⟩ : m (Subtype P)))) := by
-    simp only [map_bind, map_pure]
-    simp only [bind_pure_comp, WeaklyLawfulMonadAttach.map_attach]
-    rw (occs := [1]) [← WeaklyLawfulMonadAttach.map_attach (x := x)]
-    simp
-  rw [h'] at h
-  have := LawfulMonadAttach.canReturn_map_imp h
-  exact this
-
-public theorem LawfulMonadAttach.eq_of_canReturn_pure [Monad m] [MonadAttach m]
-    [LawfulMonad m] [LawfulMonadAttach m] {a b : α}
-    (h : MonadAttach.CanReturn (m := m) (pure a) b) :
-    a = b := by
-  let x : m (Subtype (a = ·)) := pure ⟨a, rfl⟩
-  have : pure a = Subtype.val <$> x := by simp [x]
-  rw [this] at h
-  exact LawfulMonadAttach.canReturn_map_imp h
-
-public theorem LawfulMonadAttach.canReturn_map_imp' [Monad m] [LawfulMonad m]
-    [MonadAttach m] [LawfulMonadAttach m]
-    {x : m α} {f : α → β} :
-    MonadAttach.CanReturn (f <$> x) b → Exists fun a => MonadAttach.CanReturn x a ∧ f a = b := by
-  rw [map_eq_pure_bind]
-  intro h
-  obtain ⟨a, h, h'⟩ := canReturn_bind_imp' h
-  exact ⟨a, h, eq_of_canReturn_pure h'⟩
-
-public theorem LawfulMonadAttach.canReturn_liftM_imp'
-    [Monad m] [MonadAttach m] [LawfulMonad m] [LawfulMonadAttach m]
-    [Monad n] [MonadAttach n] [LawfulMonad n] [LawfulMonadAttach n]
-    [MonadLiftT m n] [LawfulMonadLiftT m n] {x : m α} {a : α} :
-    MonadAttach.CanReturn (liftM (n := n) x) a → MonadAttach.CanReturn x a := by
-  intro h
-  simp only [← WeaklyLawfulMonadAttach.map_attach (x := x), liftM_map] at h
-  exact canReturn_map_imp h
-
-public theorem WeaklyLawfulMonadAttach.attach_bind_val
-    [Monad m] [MonadAttach m] [LawfulMonad m] [WeaklyLawfulMonadAttach m]
-    {x : m α} {f : α → m β} :
-    MonadAttach.attach x >>= (fun a => f a.val) = x >>= f := by
-  conv => rhs; simp only [← map_attach (x := x), bind_map_left]
-
-public theorem WeaklyLawfulMonadAttach.bind_attach_of_nonempty
-    [Monad m] [MonadAttach m] [LawfulMonad m] [WeaklyLawfulMonadAttach m] [Nonempty (m β)]
-    {x : m α} {f : Subtype (MonadAttach.CanReturn x) → m β} :
-    open scoped Classical in
-    MonadAttach.attach x >>= f = x >>= (fun a => if ha : MonadAttach.CanReturn x a then f ⟨a, ha⟩ else Classical.ofNonempty) := by
-  conv => rhs; simp +singlePass only [← map_attach (x := x)]
-  simp [Subtype.property]
-
-public theorem MonadAttach.attach_bind_eq_pbind
-    [Monad m] [MonadAttach m]
-    {x : m α} {f : Subtype (MonadAttach.CanReturn x) → m β} :
-    MonadAttach.attach x >>= f = MonadAttach.pbind x (fun a ha => f ⟨a, ha⟩) := by
-  simp [MonadAttach.pbind]
-
-public theorem WeaklyLawfulMonadAttach.pbind_eq_bind
-    [Monad m] [MonadAttach m] [LawfulMonad m] [WeaklyLawfulMonadAttach m]
-    {x : m α} {f : α → m β} :
-    MonadAttach.pbind x (fun a _ => f a) = x >>= f := by
-  conv => rhs; rw [← map_attach (x := x)]
-  simp [MonadAttach.pbind]
-
-public theorem WeaklyLawfulMonadAttach.pbind_eq_bind'
-    [Monad m] [MonadAttach m] [LawfulMonad m] [WeaklyLawfulMonadAttach m]
-    {x : m α} {f : α → m β} :
-    MonadAttach.pbind x (fun a _ => f a) = x >>= f := by
-  conv => rhs; rw [← map_attach (x := x)]
-  simp [MonadAttach.pbind]

src/Init/Control/Lawful/MonadLift/Lemmas.lean

@@ -6,7 +6,6 @@ Authors: Quang Dao
 module
 
 prelude
-public import Init.Control.Id
 public import Init.Control.Lawful.Basic
 public import Init.Control.Lawful.MonadLift.Basic
 
@@ -14,14 +13,6 @@ public section
 
 universe u v w
 
-theorem instMonadLiftTOfMonadLift_instMonadLiftTOfPure [Monad m] [Monad n] {_ : MonadLift m n}
-    [LawfulMonadLift m n] : instMonadLiftTOfMonadLift Id m n = Id.instMonadLiftTOfPure := by
-  have hext {a b : MonadLiftT Id n} (h : @a.monadLift = @b.monadLift) : a = b := by
-    cases a <;> cases b <;> simp_all
-  apply hext
-  ext α x
-  simp [monadLift, LawfulMonadLift.monadLift_pure]
-
 variable {m : Type u → Type v} {n : Type u → Type w} [Monad m] [Monad n] [MonadLiftT m n]
   [LawfulMonadLiftT m n] {α β : Type u}
 
@@ -32,7 +23,7 @@ theorem monadLift_map [LawfulMonad m] [LawfulMonad n] (f : α → β) (ma : m α
 
 theorem monadLift_seq [LawfulMonad m] [LawfulMonad n] (mf : m (α → β)) (ma : m α) :
     monadLift (mf <*> ma) = monadLift mf <*> (monadLift ma : n α) := by
-  simp only [seq_eq_bind_map, monadLift_map, monadLift_bind]
+  simp only [seq_eq_bind, monadLift_map, monadLift_bind]
 
 theorem monadLift_seqLeft [LawfulMonad m] [LawfulMonad n] (x : m α) (y : m β) :
     monadLift (x <* y) = (monadLift x : n α) <* (monadLift y : n β) := by

src/Init/Control/MonadAttach.lean

@@ -1,126 +0,0 @@
-/-
-Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Paul Reichert
--/
-module
-
-prelude
-public import Init.Control.Basic
-
-set_option linter.all true
-
-set_option doc.verso true
-
-/-!
-# {name (scope := "Init.Control.MonadAttach")}`MonadAttach`
-
-This module provides a mechanism for attaching proofs to the return values of monadic computations,
-producing a new monadic computation returning a {name}`Subtype`.
-
-This function is primarily used to allow definitions by [well-founded
-recursion](lean-manual://section/well-founded-recursion) that sequence computations using
-{name}`Bind.bind` (`>>=`) to prove properties about the return values of prior computations when
-a recursive call happens.
-This allows the well-founded recursion mechanism to prove that the function terminates.
--/
-
--- verso docstring is added below
-set_option linter.missingDocs false in
-public class MonadAttach (m : Type u → Type v) where
-  /--
-  A predicate that can be assumed to be true for all return values {name}`a` of actions {name}`x`
-  in {name}`m`, in all situations.
-  -/
-  CanReturn {α : Type u} : (x : m α) → (a : α) → Prop
-  /--
-  Attaches a proof of {name}`MonadAttach.CanReturn` to the return value of {name}`x`. This proof
-  can be used to prove the termination of well-founded recursive functions.
-  -/
-  attach {α : Type u} (x : m α) : m (Subtype (CanReturn x))
-
--- verso docstring is added below
-set_option linter.missingDocs false in
-public class WeaklyLawfulMonadAttach (m : Type u → Type v) [Monad m] [MonadAttach m] where
-  map_attach {α : Type u} {x : m α} : Subtype.val <$> MonadAttach.attach x = x
-
-/--
-This type class ensures that {name}`MonadAttach.CanReturn` is the unique strongest possible
-postcondition.
--/
-public class LawfulMonadAttach (m : Type u → Type v) [Monad m] [MonadAttach m] extends
-    WeaklyLawfulMonadAttach m where
-  canReturn_map_imp {α : Type u} {P : α → Prop} {x : m (Subtype P)} {a : α} :
-      MonadAttach.CanReturn (Subtype.val <$> x) a → P a
-
-/--
-Like {name}`Bind.bind`, {name}`pbind` sequences two computations {lean}`x : m α` and {lean}`f`,
-allowing the second to depend on the value computed by the first.
-But other than with {name}`Bind.bind`, the second computation can also depend on a proof that
-the return value {given}`a` of {name}`x` satisfies {lean}`MonadAttach.CanReturn x a`.
--/
-public def MonadAttach.pbind [Monad m] [MonadAttach m]
-    (x : m α) (f : (a : α) → MonadAttach.CanReturn x a → m β) : m β :=
-  MonadAttach.attach x >>= (fun ⟨a, ha⟩ => f a ha)
-
-/--
-A {lean}`MonadAttach` instance where all return values are possible and {name}`attach` adds no
-information to the return value, except a trivial proof of {name}`True`.
-
-This instance is used whenever no more useful {name}`MonadAttach` instance can be implemented.
-It always has a {name}`WeaklyLawfulMonadAttach`, but usually no {name}`LawfulMonadAttach` instance.
--/
-@[expose]
-public protected def MonadAttach.trivial {m : Type u → Type v} [Monad m] : MonadAttach m where
-  CanReturn _ _ := True
-  attach x := (⟨·, .intro⟩) <$> x
-
-section
-
-variable (α : Type u) [∀ m, Monad m] [∀ m, MonadAttach m]
-
-set_option doc.verso true
-
-/--
-For every {given}`x : m α`, this type class provides a predicate {lean}`MonadAttach.CanReturn x`
-and a way to attach a proof of this predicate to the return values of {name}`x` by providing
-an element {lean}`MonadAttach.attach x` of {lean}`m { a : α // MonadAttach.CanReturn x a }`.
-
-Instances should abide the law {lean}`Subtype.val <$> MonadAttach.attach x = x`, which is encoded by
-the {name}`WeaklyLawfulMonadAttach` type class. The stronger type class {name}`LawfulMonadAttach`
-ensures that {lean}`MonadAttach.CanReturn x` is the _unique_ strongest possible predicate.
-
-Similarly to {name (scope := "Init.Data.List.Attach")}`List.attach`, the purpose of
-{name}`MonadAttach` is to attach proof terms necessary for well-founded termination proofs.
-The iterator library relies on {name}`MonadAttach` for combinators such as
-{name (scope := "Init.Data.Iterators")}`Std.Iter.filterM` in order to automatically attach
-information about the monadic predicate's behavior that could be relevant for the termination
-behavior of the iterator.
-
-*Limitations*:
-
-For many monads, there is a strongly lawful {lean}`MonadAttach` instance, but there are exceptions.
-For example, there is no way to provide a computable {lean}`MonadAttach` instance for the CPS monad
-transformers
-{name (scope := "Init.Control.StateCps")}`StateCpsT` and
-{name (scope := "Init.Control.StateCps")}`ExceptCpsT` with a predicate that is not always
-{name}`True`. Therefore, such CPS monads only provide the trivial {lean}`MonadAttach` instance
-{lean}`MonadAttach.trivial` together with {name}`WeaklyLawfulMonadAttach`, but without
-{name}`LawfulMonadAttach`.
-
-For most monads with side effects, {lean}`MonadAttach` is too weak to fully capture the behavior of
-computations because the postcondition represented by {name}`MonadAttach.CanReturn` neither depends
-on the prior internal state of the monad, nor does it contain information about how the state of the
-monad changes with the computation.
--/
-add_decl_doc MonadAttach
-
-/--
-This type class ensures that every monadic action {given}`x : m α` can be recovered by stripping the
-proof component from the subtypes returned by
-{lean}`(MonadAttach.attach x) : m { a : α // MonadAttach.CanReturn x a }` . In other words,
-the type class ensures that {lean}`Subtype.val <$> MonadAttach.attach x = x`.
--/
-add_decl_doc WeaklyLawfulMonadAttach
-
-end

src/Init/Control/Option.lean

@@ -112,12 +112,6 @@ instance (ε : Type u) [MonadExceptOf ε m] : MonadExceptOf ε (OptionT m) where
   throw e           := OptionT.mk <| throwThe ε e
   tryCatch x handle := OptionT.mk <| tryCatchThe ε x handle
 
-instance [MonadAttach m] : MonadAttach (OptionT m) where
-  CanReturn x a := MonadAttach.CanReturn x.run (some a)
-  attach x := .mk ((fun
-      | ⟨some a, h⟩ => some ⟨a, h⟩
-      | ⟨none, _⟩ => none) <$> MonadAttach.attach x.run)
-
 end OptionT
 
 instance [Monad m] : MonadControl m (OptionT m) where

src/Init/Control/Reader.lean

@@ -51,7 +51,3 @@ A monad with access to a read-only value of type `ρ`. The value can be locally
 `withReader`, but it cannot be mutated.
 -/
 abbrev ReaderM (ρ : Type u) := ReaderT ρ Id
-
-instance [Monad m] [MonadAttach m] : MonadAttach (ReaderT ρ m) where
-  CanReturn x a := Exists (fun r => MonadAttach.CanReturn (x.run r) a)
-  attach x := fun r => (fun ⟨a, h⟩ => ⟨a, r, h⟩) <$> MonadAttach.attach (x.run r)

src/Init/Control/State.lean

@@ -25,12 +25,6 @@ of a value and a state.
 @[expose] def StateT (σ : Type u) (m : Type u → Type v) (α : Type u) : Type (max u v) :=
   σ → m (α × σ)
 
-/--
-Interpret `σ → m (α × σ)` as an element of `StateT σ m α`.
--/
-@[always_inline, inline, expose]
-def StateT.mk {σ : Type u} {m : Type u → Type v} {α : Type u} (x : σ → m (α × σ)) : StateT σ m α := x
-
 /--
 Executes an action from a monad with added state in the underlying monad `m`. Given an initial
 state, it returns a value paired with the final state.
@@ -204,7 +198,3 @@ instance StateT.tryFinally {m : Type u → Type v} {σ : Type u} [MonadFinally m
       | some (a, s') => h (some a) s'
       | none         => h none s
     pure ((a, b), s'')
-
-instance [Monad m] [MonadAttach m] : MonadAttach (StateT σ m) where
-  CanReturn x a := Exists fun s => Exists fun s' => MonadAttach.CanReturn (x.run s) (a, s')
-  attach x := fun s => (fun ⟨⟨a, s'⟩, h⟩ => ⟨⟨a, s, s', h⟩, s'⟩) <$> MonadAttach.attach (x.run s)

src/Init/Control/StateCps.lean

@@ -68,13 +68,6 @@ instance : MonadStateOf σ (StateCpsT σ m) where
   set s := fun _ _ k => k ⟨⟩ s
   modifyGet f := fun _ s k => let (a, s) := f s; k a s
 
-/--
-For continuation monads, it is not possible to provide a computable `MonadAttach` instance that
-actually adds information about the return value. Therefore, this instance always attaches a proof
-of `True`.
--/
-instance : MonadAttach (StateCpsT ε m) := .trivial
-
 /--
 Runs an action from the underlying monad in the monad with state. The state is not modified.
 

src/Init/Control/StateRef.lean

@@ -64,7 +64,6 @@ instance [Monad m] : Monad (StateRefT' ω σ m) := inferInstanceAs (Monad (Reade
 instance : MonadLift m (StateRefT' ω σ m) := ⟨StateRefT'.lift⟩
 instance (σ m) : MonadFunctor m (StateRefT' ω σ m) := inferInstanceAs (MonadFunctor m (ReaderT _ _))
 instance [Alternative m] [Monad m] : Alternative (StateRefT' ω σ m) := inferInstanceAs (Alternative (ReaderT _ _))
-instance [Monad m] [MonadAttach m] : MonadAttach (StateRefT' ω σ m) := inferInstanceAs (MonadAttach (ReaderT _ _))
 
 /--
 Retrieves the current value of the monad's mutable state.

src/Init/Core.lean

@@ -201,7 +201,6 @@ An element of `α ⊕ β` is either an `a : α` wrapped in `Sum.inl` or a `b :
 indication of which of the two types was chosen. The union of a singleton set with itself contains
 one element, while `Unit ⊕ Unit` contains distinct values `inl ()` and `inr ()`.
 -/
-@[suggest_for Either]
 inductive Sum (α : Type u) (β : Type v) where
   /-- Left injection into the sum type `α ⊕ β`. -/
   | inl (val : α) : Sum α β
@@ -337,7 +336,7 @@ inductive Exists {α : Sort u} (p : α → Prop) : Prop where
 An indication of whether a loop's body terminated early that's used to compile the `for x in xs`
 notation.
 
-A collection's `ForIn` or `ForIn'` instance describes how to iterate over its elements. The monadic
+A collection's `ForIn` or `ForIn'` instance describe's how to iterate over its elements. The monadic
 action that represents the body of the loop returns a `ForInStep α`, where `α` is the local state
 used to implement features such as `let mut`.
 -/
@@ -378,7 +377,7 @@ class ForIn (m : Type u₁ → Type u₂) (ρ : Type u) (α : outParam (Type v))
   More information about the translation of `for` loops into `ForIn.forIn` is available in [the Lean
   reference manual](lean-manual://section/monad-iteration-syntax).
   -/
-  forIn {β} (xs : ρ) (b : β) (f : α → β → m (ForInStep β)) : m β
+  forIn {β} [Monad m] (xs : ρ) (b : β) (f : α → β → m (ForInStep β)) : m β
 
 export ForIn (forIn)
 
@@ -406,7 +405,7 @@ class ForIn' (m : Type u₁ → Type u₂) (ρ : Type u) (α : outParam (Type v)
   More information about the translation of `for` loops into `ForIn'.forIn'` is available in [the
   Lean reference manual](lean-manual://section/monad-iteration-syntax).
   -/
-  forIn' {β} (x : ρ) (b : β) (f : (a : α) → a ∈ x → β → m (ForInStep β)) : m β
+  forIn' {β} [Monad m] (x : ρ) (b : β) (f : (a : α) → a ∈ x → β → m (ForInStep β)) : m β
 
 export ForIn' (forIn')
 
@@ -510,12 +509,12 @@ abbrev SSuperset [HasSSubset α] (a b : α) := SSubset b a
 
 /-- Notation type class for the union operation `∪`. -/
 class Union (α : Type u) where
-  /-- `a ∪ b` is the union of `a` and `b`. -/
+  /-- `a ∪ b` is the union of`a` and `b`. -/
   union : α → α → α
 
 /-- Notation type class for the intersection operation `∩`. -/
 class Inter (α : Type u) where
-  /-- `a ∩ b` is the intersection of `a` and `b`. -/
+  /-- `a ∩ b` is the intersection of`a` and `b`. -/
   inter : α → α → α
 
 /-- Notation type class for the set difference `\`. -/
@@ -538,10 +537,10 @@ infix:50 " ⊇ " => Superset
 /-- Strict superset relation: `a ⊃ b`  -/
 infix:50 " ⊃ " => SSuperset
 
-/-- `a ∪ b` is the union of `a` and `b`. -/
+/-- `a ∪ b` is the union of`a` and `b`. -/
 infixl:65 " ∪ " => Union.union
 
-/-- `a ∩ b` is the intersection of `a` and `b`. -/
+/-- `a ∩ b` is the intersection of`a` and `b`. -/
 infixl:70 " ∩ " => Inter.inter
 
 /--
@@ -601,6 +600,17 @@ export LawfulSingleton (insert_empty_eq)
 
 attribute [simp] insert_empty_eq
 
+@[deprecated insert_empty_eq (since := "2025-03-12")]
+theorem insert_emptyc_eq [EmptyCollection β] [Insert α β] [Singleton α β]
+    [LawfulSingleton α β] (x : α) : (insert x ∅ : β) = singleton x :=
+  insert_empty_eq _
+
+@[deprecated insert_empty_eq (since := "2025-03-12")]
+theorem LawfulSingleton.insert_emptyc_eq [EmptyCollection β] [Insert α β] [Singleton α β]
+    [LawfulSingleton α β] (x : α) : (insert x ∅ : β) = singleton x :=
+  insert_empty_eq _
+
+
 /-- Type class used to implement the notation `{ a ∈ c | p a }` -/
 class Sep (α : outParam <| Type u) (γ : Type v) where
   /-- Computes `{ a ∈ c | p a }`. -/
@@ -940,7 +950,9 @@ theorem HEq.subst {p : (T : Sort u) → T → Prop} (h₁ : a ≍ b) (h₂ : p
 @[symm] theorem HEq.symm (h : a ≍ b) : b ≍ a :=
   h.rec (HEq.refl a)
 
-
+/-- Propositionally equal terms are also heterogeneously equal. -/
+theorem heq_of_eq (h : a = a') : a ≍ a' :=
+  Eq.subst h (HEq.refl a)
 
 /-- Heterogeneous equality is transitive. -/
 theorem HEq.trans (h₁ : a ≍ b) (h₂ : b ≍ c) : a ≍ c :=
@@ -1083,6 +1095,14 @@ theorem of_toBoolUsing_eq_true {p : Prop} {d : Decidable p} (h : toBoolUsing d =
 theorem of_toBoolUsing_eq_false {p : Prop} {d : Decidable p} (h : toBoolUsing d = false) : ¬p :=
   of_decide_eq_false h
 
+set_option linter.missingDocs false in
+@[deprecated of_toBoolUsing_eq_true (since := "2025-04-04")]
+abbrev ofBoolUsing_eq_true := @of_toBoolUsing_eq_true
+
+set_option linter.missingDocs false in
+@[deprecated of_toBoolUsing_eq_false (since := "2025-04-04")]
+abbrev ofBoolUsing_eq_false := @of_toBoolUsing_eq_false
+
 instance : Decidable True :=
   isTrue trivial
 
@@ -1145,7 +1165,6 @@ end
     else isFalse (fun h => absurd (h hp) hq)
   else isTrue (fun h => absurd h hp)
 
-@[inline]
 instance {p q} [Decidable p] [Decidable q] : Decidable (p ↔ q) :=
   if hp : p then
     if hq : q then
@@ -1187,13 +1206,17 @@ theorem dif_neg {c : Prop} {h : Decidable c} (hnc : ¬c) {α : Sort u} {t : c
   | isTrue hc   => absurd hc hnc
   | isFalse _   => rfl
 
-@[macro_inline]
+-- Remark: dite and ite are "defally equal" when we ignore the proofs.
+theorem dif_eq_if (c : Prop) {h : Decidable c} {α : Sort u} (t : α) (e : α) : dite c (fun _ => t) (fun _ => e) = ite c t e :=
+  match h with
+  | isTrue _    => rfl
+  | isFalse _   => rfl
+
 instance {c t e : Prop} [dC : Decidable c] [dT : Decidable t] [dE : Decidable e] : Decidable (if c then t else e) :=
   match dC with
   | isTrue _   => dT
   | isFalse _  => dE
 
-@[inline]
 instance {c : Prop} {t : c → Prop} {e : ¬c → Prop} [dC : Decidable c] [dT : ∀ h, Decidable (t h)] [dE : ∀ h, Decidable (e h)] : Decidable (if h : c then t h else e h) :=
   match dC with
   | isTrue hc  => dT hc
@@ -1344,12 +1367,12 @@ namespace Subtype
 theorem exists_of_subtype {α : Type u} {p : α → Prop} : { x // p x } → Exists (fun x => p x)
   | ⟨a, h⟩ => ⟨a, h⟩
 
-variable {α : Sort u} {p : α → Prop}
+set_option linter.missingDocs false in
+@[deprecated exists_of_subtype (since := "2025-04-04")]
+abbrev existsOfSubtype := @exists_of_subtype
 
-protected theorem ext : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2
-  | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
+variable {α : Type u} {p : α → Prop}
 
-@[deprecated Subtype.ext (since := "2025-10-26")]
 protected theorem eq : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2
   | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
 
@@ -1364,12 +1387,12 @@ instance {α : Type u} {p : α → Prop} [BEq α] [ReflBEq α] : ReflBEq {x : α
   rfl {x} := BEq.refl x.1
 
 instance {α : Type u} {p : α → Prop} [BEq α] [LawfulBEq α] : LawfulBEq {x : α // p x} where
-  eq_of_beq h := Subtype.ext (eq_of_beq h)
+  eq_of_beq h := Subtype.eq (eq_of_beq h)
 
-instance {α : Sort u} {p : α → Prop} [DecidableEq α] : DecidableEq {x : α // p x} :=
+instance {α : Type u} {p : α → Prop} [DecidableEq α] : DecidableEq {x : α // p x} :=
   fun ⟨a, h₁⟩ ⟨b, h₂⟩ =>
     if h : a = b then isTrue (by subst h; exact rfl)
-    else isFalse (fun h' => Subtype.noConfusion rfl .rfl (heq_of_eq h') (fun h' => absurd (eq_of_heq h') h))
+    else isFalse (fun h' => Subtype.noConfusion h' (fun h' => absurd h' h))
 
 end Subtype
 
@@ -1428,8 +1451,8 @@ instance [DecidableEq α] [DecidableEq β] : DecidableEq (α × β) :=
     | isTrue e₁ =>
       match decEq b b' with
       | isTrue e₂  => isTrue (e₁ ▸ e₂ ▸ rfl)
-      | isFalse n₂ => isFalse fun h => Prod.noConfusion rfl rfl (heq_of_eq h) fun _   e₂' => absurd (eq_of_heq e₂') n₂
-    | isFalse n₁ => isFalse fun h => Prod.noConfusion rfl rfl (heq_of_eq h) fun e₁' _   => absurd (eq_of_heq e₁') n₁
+      | isFalse n₂ => isFalse fun h => Prod.noConfusion h fun _   e₂' => absurd e₂' n₂
+    | isFalse n₁ => isFalse fun h => Prod.noConfusion h fun e₁' _   => absurd e₁' n₁
 
 instance [BEq α] [BEq β] : BEq (α × β) where
   beq := fun (a₁, b₁) (a₂, b₂) => a₁ == a₂ && b₁ == b₂
@@ -1467,8 +1490,6 @@ def Prod.map {α₁ : Type u₁} {α₂ : Type u₂} {β₁ : Type v₁} {β₂
 
 @[simp] theorem Prod.map_apply (f : α → β) (g : γ → δ) (x) (y) :
     Prod.map f g (x, y) = (f x, g y) := rfl
-
--- We add `@[grind =]` to these in `Init.Data.Prod`.
 @[simp] theorem Prod.map_fst (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).1 = f x.1 := rfl
 @[simp] theorem Prod.map_snd (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).2 = g x.2 := rfl
 
@@ -1485,24 +1506,20 @@ protected theorem PSigma.eta {α : Sort u} {β : α → Sort v} {a₁ a₂ : α}
 
 /-! # Universe polymorphic unit -/
 
-theorem PUnit.ext (a b : PUnit) : a = b := by
-  cases a; cases b; exact rfl
-
-@[deprecated PUnit.ext (since := "2025-10-26")]
 theorem PUnit.subsingleton (a b : PUnit) : a = b := by
   cases a; cases b; exact rfl
 
 theorem PUnit.eq_punit (a : PUnit) : a = ⟨⟩ :=
-  PUnit.ext a ⟨⟩
+  PUnit.subsingleton a ⟨⟩
 
 instance : Subsingleton PUnit :=
-  Subsingleton.intro PUnit.ext
+  Subsingleton.intro PUnit.subsingleton
 
 instance : Inhabited PUnit where
   default := ⟨⟩
 
 instance : DecidableEq PUnit :=
-  fun a b => isTrue (PUnit.ext a b)
+  fun a b => isTrue (PUnit.subsingleton a b)
 
 /-! # Setoid -/
 
@@ -1589,7 +1606,7 @@ gen_injective_theorems% PSum
 gen_injective_theorems% Sigma
 gen_injective_theorems% String
 gen_injective_theorems% String.Pos.Raw
-gen_injective_theorems% Substring.Raw
+gen_injective_theorems% Substring
 gen_injective_theorems% Subtype
 gen_injective_theorems% Sum
 gen_injective_theorems% Task
@@ -2506,7 +2523,8 @@ class Antisymm (r : α → α → Prop) : Prop where
   /-- An antisymmetric relation `r` satisfies `r a b → r b a → a = b`. -/
   antisymm (a b : α) : r a b → r b a → a = b
 
-/-- `Asymm r` means that the binary relation `r` is asymmetric, that is, `r a b → ¬ r b a`. -/
+/-- `Asymm r` means that the binary relation `r` is asymmetric, that is,
+`r a b → ¬ r b a`. -/
 class Asymm (r : α → α → Prop) : Prop where
   /-- An asymmetric relation satisfies `r a b → ¬ r b a`. -/
   asymm : ∀ a b, r a b → ¬r b a
@@ -2516,19 +2534,16 @@ class Symm (r : α → α → Prop) : Prop where
   /-- A symmetric relation satisfies `r a b → r b a`. -/
   symm : ∀ a b, r a b → r b a
 
-/-- `Total X r` means that the binary relation `r` on `X` is total, that is, `r a b` or `r b a`. -/
+/-- `Total X r` means that the binary relation `r` on `X` is total, that is, that for any
+`x y : X` we have `r x y` or `r y x`. -/
 class Total (r : α → α → Prop) : Prop where
-  /-- A total relation satisfies `r a b` or `r b a`. -/
+  /-- A total relation satisfies `r a b ∨ r b a`. -/
   total : ∀ a b, r a b ∨ r b a
 
-/-- `Irrefl r` means the binary relation `r` is irreflexive, that is, `r x x` never holds. -/
+/-- `Irrefl r` means the binary relation `r` is irreflexive, that is, `r x x` never
+holds. -/
 class Irrefl (r : α → α → Prop) : Prop where
   /-- An irreflexive relation satisfies `¬ r a a`. -/
   irrefl : ∀ a, ¬r a a
 
-/-- `Trichotomous r` says that `r` is trichotomous, that is, `¬ r a b → ¬ r b a → a = b`. -/
-class Trichotomous (r : α → α → Prop) : Prop where
-  /-- An trichotomous relation `r` satisfies `¬ r a b → ¬ r b a → a = b`. -/
-  trichotomous (a b : α) : ¬ r a b → ¬ r b a → a = b
-
 end Std

src/Init/Data.lean

@@ -6,6 +6,7 @@ Authors: Leonardo de Moura
 module
 
 prelude
+public import Init.Data.Basic
 public import Init.Data.Nat
 public import Init.Data.Bool
 public import Init.Data.BitVec

src/Init/Data/Array/Attach.lean

@@ -572,6 +572,9 @@ def unattach {α : Type _} {p : α → Prop} (xs : Array { x // p x }) : Array
 @[simp] theorem unattach_empty {p : α → Prop} : (#[] : Array { x // p x }).unattach = #[] := by
   simp [unattach]
 
+@[deprecated unattach_empty (since := "2025-05-26")]
+abbrev unattach_nil := @unattach_empty
+
 @[simp] theorem unattach_push {p : α → Prop} {a : { x // p x }} {xs : Array { x // p x }} :
     (xs.push a).unattach = xs.unattach.push a.1 := by
   simp only [unattach, Array.map_push]
@@ -746,6 +749,9 @@ and simplifies these to the function directly taking the value.
     (Array.replicate n x).unattach = Array.replicate n x.1 := by
   simp [unattach]
 
+@[deprecated unattach_replicate (since := "2025-03-18")]
+abbrev unattach_mkArray := @unattach_replicate
+
 /-! ### Well-founded recursion preprocessing setup -/
 
 @[wf_preprocess] theorem map_wfParam {xs : Array α} {f : α → β} :

src/Init/Data/Array/Basic.lean

@@ -209,6 +209,20 @@ Examples:
 def replicate {α : Type u} (n : Nat) (v : α) : Array α where
   toList := List.replicate n v
 
+/--
+Creates an array that contains `n` repetitions of `v`.
+
+The corresponding `List` function is `List.replicate`.
+
+Examples:
+ * `Array.mkArray 2 true = #[true, true]`
+ * `Array.mkArray 3 () = #[(), (), ()]`
+ * `Array.mkArray 0 "anything" = #[]`
+-/
+@[extern "lean_mk_array", deprecated replicate (since := "2025-03-18")]
+def mkArray {α : Type u} (n : Nat) (v : α) : Array α where
+  toList := List.replicate n v
+
 /--
 Swaps two elements of an array. The modification is performed in-place when the reference to the
 array is unique.
@@ -226,7 +240,7 @@ def swap (xs : Array α) (i j : @& Nat) (hi : i < xs.size := by get_elem_tactic)
   let xs'  := xs.set i v₂
   xs'.set j v₁ (Nat.lt_of_lt_of_eq hj (size_set _).symm)
 
-@[simp, grind =] theorem size_swap {xs : Array α} {i j : Nat} {hi hj} : (xs.swap i j hi hj).size = xs.size := by
+@[simp] theorem size_swap {xs : Array α} {i j : Nat} {hi hj} : (xs.swap i j hi hj).size = xs.size := by
   change ((xs.set i xs[j]).set j xs[i]
     (Nat.lt_of_lt_of_eq hj (size_set _).symm)).size = xs.size
   rw [size_set, size_set]
@@ -242,7 +256,7 @@ Examples:
 * `#["red", "green", "blue", "brown"].swapIfInBounds 0 4 = #["red", "green", "blue", "brown"]`
 * `#["red", "green", "blue", "brown"].swapIfInBounds 9 2 = #["red", "green", "blue", "brown"]`
 -/
-@[extern "lean_array_swap", expose]
+@[extern "lean_array_swap", grind]
 def swapIfInBounds (xs : Array α) (i j : @& Nat) : Array α :=
   if h₁ : i < xs.size then
   if h₂ : j < xs.size then swap xs i j
@@ -448,7 +462,7 @@ Examples:
 -/
 abbrev take (xs : Array α) (i : Nat) : Array α := extract xs 0 i
 
-@[simp, grind =] theorem take_eq_extract {xs : Array α} {i : Nat} : xs.take i = xs.extract 0 i := rfl
+@[simp] theorem take_eq_extract {xs : Array α} {i : Nat} : xs.take i = xs.extract 0 i := rfl
 
 /--
 Removes the first `i` elements of `xs`. If `xs` has fewer than `i` elements, the new array is empty.
@@ -462,7 +476,7 @@ Examples:
 -/
 abbrev drop (xs : Array α) (i : Nat) : Array α := extract xs i xs.size
 
-@[simp, grind =] theorem drop_eq_extract {xs : Array α} {i : Nat} : xs.drop i = xs.extract i xs.size := rfl
+@[simp] theorem drop_eq_extract {xs : Array α} {i : Nat} : xs.drop i = xs.extract i xs.size := rfl
 
 @[inline]
 unsafe def modifyMUnsafe [Monad m] (xs : Array α) (i : Nat) (f : α → m α) : m (Array α) := do
@@ -570,7 +584,7 @@ protected def forIn' {α : Type u} {β : Type v} {m : Type v → Type w} [Monad
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
 
-instance [Monad m] : ForIn' m (Array α) α inferInstance where
+instance : ForIn' m (Array α) α inferInstance where
   forIn' := Array.forIn'
 
 -- No separate `ForIn` instance is required because it can be derived from `ForIn'`.
@@ -589,8 +603,6 @@ unsafe def foldlMUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Mon
   if start < stop then
     if stop ≤ as.size then
       fold (USize.ofNat start) (USize.ofNat stop) init
-    else if start < as.size then
-      fold (USize.ofNat start) (USize.ofNat as.size) init
     else
       pure init
   else
@@ -1003,7 +1015,7 @@ unless `start < stop`. By default, the entire array is used.
 protected def forM {α : Type u} {m : Type v → Type w} [Monad m] (f : α → m PUnit) (as : Array α) (start := 0) (stop := as.size) : m PUnit :=
   as.foldlM (fun _ => f) ⟨⟩ start stop
 
-instance [Monad m] : ForM m (Array α) α where
+instance : ForM m (Array α) α where
   forM xs f := Array.forM f xs
 
 -- We simplify `Array.forM` to `forM`.
@@ -1297,7 +1309,7 @@ decreasing_by simp_wf; decreasing_trivial_pre_omega
 
 
 /--
-Returns the index of the first element equal to `a`, or `none` if no element is equal
+Returns the index of the first element equal to `a`, or the size of the array if no element is equal
 to `a`. The index is returned as a `Fin`, which guarantees that it is in bounds.
 
 Examples:
@@ -1350,7 +1362,7 @@ Examples:
 * `#[2, 4, 5, 6].any (· % 2 = 0) = true`
 * `#[2, 4, 5, 6].any (· % 2 = 1) = true`
 -/
-@[inline, expose, suggest_for Array.some]
+@[inline, expose]
 def any (as : Array α) (p : α → Bool) (start := 0) (stop := as.size) : Bool :=
   Id.run <| as.anyM (pure <| p ·) start stop
 
@@ -1368,7 +1380,7 @@ Examples:
 * `#[2, 4, 6].all (· % 2 = 0) = true`
 * `#[2, 4, 5, 6].all (· % 2 = 0) = false`
 -/
-@[inline, suggest_for Array.every]
+@[inline]
 def all (as : Array α) (p : α → Bool) (start := 0) (stop := as.size) : Bool :=
   Id.run <| as.allM (pure <| p ·) start stop
 
@@ -1706,7 +1718,7 @@ def popWhile (p : α → Bool) (as : Array α) : Array α :=
     as
 decreasing_by simp_wf; decreasing_trivial_pre_omega
 
-@[simp, grind =] theorem popWhile_empty {p : α → Bool} :
+@[simp] theorem popWhile_empty {p : α → Bool} :
     popWhile p #[] = #[] := by
   simp [popWhile]
 
@@ -1753,8 +1765,7 @@ termination_by xs.size - i
 decreasing_by simp_wf; exact Nat.sub_succ_lt_self _ _ h
 
 -- This is required in `Lean.Data.PersistentHashMap`.
-@[simp, grind =]
-theorem size_eraseIdx {xs : Array α} (i : Nat) (h) : (xs.eraseIdx i h).size = xs.size - 1 := by
+@[simp] theorem size_eraseIdx {xs : Array α} (i : Nat) (h) : (xs.eraseIdx i h).size = xs.size - 1 := by
   induction xs, i, h using Array.eraseIdx.induct with
   | @case1 xs i h h' xs' ih =>
     unfold eraseIdx
@@ -2136,3 +2147,5 @@ instance [ToString α] : ToString (Array α) where
   toString xs := String.Internal.append "#" (toString xs.toList)
 
 end Array
+
+export Array (mkArray)

src/Init/Data/Array/Bootstrap.lean

@@ -31,7 +31,7 @@ theorem foldlM_toList.aux [Monad m]
   · cases Nat.not_le_of_gt ‹_› (Nat.zero_add _ ▸ H)
   · rename_i i; rw [Nat.succ_add] at H
     simp [foldlM_toList.aux (j := j+1) H]
-    rw (occs := [2]) [← List.getElem_cons_drop ‹_›]
+    rw (occs := [2]) [← List.getElem_cons_drop_succ_eq_drop ‹_›]
     simp
   · rw [List.drop_of_length_le (Nat.ge_of_not_lt ‹_›)]; simp
 
@@ -73,6 +73,9 @@ theorem foldrM_eq_reverse_foldlM_toList [Monad m] {f : α → β → m β} {init
   rcases xs with ⟨xs⟩
   simp [push, List.concat_eq_append]
 
+@[deprecated toList_push (since := "2025-05-26")]
+abbrev push_toList := @toList_push
+
 @[simp, grind =] theorem toListAppend_eq {xs : Array α} {l : List α} : xs.toListAppend l = xs.toList ++ l := by
   simp [toListAppend, ← foldr_toList]
 
@@ -97,15 +100,9 @@ theorem foldrM_eq_reverse_foldlM_toList [Monad m] {f : α → β → m β} {init
 @[simp, grind =] theorem empty_append {xs : Array α} : #[] ++ xs = xs := by
   apply ext'; simp only [toList_append, List.nil_append]
 
-@[simp] theorem append_assoc {xs ys zs : Array α} : xs ++ ys ++ zs = xs ++ (ys ++ zs) := by
+@[simp, grind _=_] theorem append_assoc {xs ys zs : Array α} : xs ++ ys ++ zs = xs ++ (ys ++ zs) := by
   apply ext'; simp only [toList_append, List.append_assoc]
 
-grind_pattern append_assoc => (xs ++ ys) ++ zs where
-  xs =/= #[]; ys =/= #[]; zs =/= #[]
-
-grind_pattern append_assoc => xs ++ (ys ++ zs) where
-  xs =/= #[]; ys =/= #[]; zs =/= #[]
-
 @[simp] theorem appendList_eq_append {xs : Array α} {l : List α} : xs.appendList l = xs ++ l := rfl
 
 @[simp, grind =] theorem toList_appendList {xs : Array α} {l : List α} :
@@ -113,4 +110,6 @@ grind_pattern append_assoc => xs ++ (ys ++ zs) where
   rw [← appendList_eq_append]; unfold Array.appendList
   induction l generalizing xs <;> simp [*]
 
+
+
 end Array

src/Init/Data/Array/Count.lean

@@ -62,12 +62,12 @@ theorem size_eq_countP_add_countP {xs : Array α} : xs.size = countP p xs + coun
   rcases xs with ⟨xs⟩
   simp [List.length_eq_countP_add_countP (p := p)]
 
+@[grind =]
 theorem countP_eq_size_filter {xs : Array α} : countP p xs = (filter p xs).size := by
   rcases xs with ⟨xs⟩
   simp [List.countP_eq_length_filter]
 
-grind_pattern countP_eq_size_filter => xs.countP p, xs.filter p
-
+@[grind =]
 theorem countP_eq_size_filter' : countP p = size ∘ filter p := by
   funext xs
   apply countP_eq_size_filter
@@ -99,6 +99,9 @@ theorem countP_le_size : countP p xs ≤ xs.size := by
 theorem countP_replicate {a : α} {n : Nat} : countP p (replicate n a) = if p a then n else 0 := by
   simp [← List.toArray_replicate, List.countP_replicate]
 
+@[deprecated countP_replicate (since := "2025-03-18")]
+abbrev countP_mkArray := @countP_replicate
+
 theorem boole_getElem_le_countP {xs : Array α} {i : Nat} (h : i < xs.size) :
     (if p xs[i] then 1 else 0) ≤ xs.countP p := by
   rcases xs with ⟨xs⟩
@@ -259,9 +262,15 @@ theorem count_eq_size {xs : Array α} : count a xs = xs.size ↔ ∀ b ∈ xs, a
 @[simp] theorem count_replicate_self {a : α} {n : Nat} : count a (replicate n a) = n := by
   simp [← List.toArray_replicate]
 
+@[deprecated count_replicate_self (since := "2025-03-18")]
+abbrev count_mkArray_self := @count_replicate_self
+
 theorem count_replicate {a b : α} {n : Nat} : count a (replicate n b) = if b == a then n else 0 := by
   simp [← List.toArray_replicate, List.count_replicate]
 
+@[deprecated count_replicate (since := "2025-03-18")]
+abbrev count_mkArray := @count_replicate
+
 theorem filter_beq {xs : Array α} (a : α) : xs.filter (· == a) = replicate (count a xs) a := by
   rcases xs with ⟨xs⟩
   simp [List.filter_beq]
@@ -275,6 +284,9 @@ theorem replicate_count_eq_of_count_eq_size {xs : Array α} (h : count a xs = xs
   rw [← toList_inj]
   simp [List.replicate_count_eq_of_count_eq_length (by simpa using h)]
 
+@[deprecated replicate_count_eq_of_count_eq_size (since := "2025-03-18")]
+abbrev mkArray_count_eq_of_count_eq_size := @replicate_count_eq_of_count_eq_size
+
 @[simp] theorem count_filter {xs : Array α} (h : p a) : count a (filter p xs) = count a xs := by
   rcases xs with ⟨xs⟩
   simp [List.count_filter, h]

src/Init/Data/Array/DecidableEq.lean

@@ -89,57 +89,11 @@ theorem isEqv_self_beq [BEq α] [ReflBEq α] (xs : Array α) : Array.isEqv xs xs
 theorem isEqv_self [DecidableEq α] (xs : Array α) : Array.isEqv xs xs (· = ·) = true := by
   simp [isEqv, isEqvAux_self]
 
-def instDecidableEqImpl [DecidableEq α] : DecidableEq (Array α) := fun xs ys =>
-  match h:isEqv xs ys (fun a b => a = b) with
-  | true  => isTrue (eq_of_isEqv xs ys h)
-  | false => isFalse (by subst ·; rw [isEqv_self] at h; contradiction)
-
-instance instDecidableEq [DecidableEq α] : DecidableEq (Array α) := fun xs ys =>
-  match xs with
-  | ⟨[]⟩ =>
-    match ys with
-    | ⟨[]⟩ => isTrue rfl
-    | ⟨_ :: _⟩ => isFalse (fun h => Array.noConfusion rfl (heq_of_eq h) (fun h => List.noConfusion rfl h))
-  | ⟨a :: as⟩ =>
-    match ys with
-    | ⟨[]⟩ => isFalse (fun h => Array.noConfusion rfl (heq_of_eq h) (fun h => List.noConfusion rfl h))
-    | ⟨b :: bs⟩ => instDecidableEqImpl ⟨a :: as⟩ ⟨b :: bs⟩
-
-@[csimp]
-theorem instDecidableEq_csimp : @instDecidableEq = @instDecidableEqImpl :=
-  Subsingleton.allEq _ _
-
-/--
-Equality with `#[]` is decidable even if the underlying type does not have decidable equality.
--/
-instance instDecidableEqEmp (xs : Array α) : Decidable (xs = #[]) :=
-  match xs with
-  | ⟨[]⟩ => isTrue rfl
-  | ⟨_ :: _⟩ => isFalse (fun h => Array.noConfusion rfl (heq_of_eq h) (fun h => List.noConfusion rfl h))
-
-/--
-Equality with `#[]` is decidable even if the underlying type does not have decidable equality.
--/
-instance instDecidableEmpEq (ys : Array α) : Decidable (#[] = ys) :=
-  match ys with
-  | ⟨[]⟩ => isTrue rfl
-  | ⟨_ :: _⟩ => isFalse (fun h => Array.noConfusion rfl (heq_of_eq h) (fun h => List.noConfusion rfl h))
-
-@[inline]
-def instDecidableEqEmpImpl (xs : Array α) : Decidable (xs = #[]) :=
-  decidable_of_iff xs.isEmpty <| by rcases xs with ⟨⟨⟩⟩ <;> simp [Array.isEmpty]
-
-@[inline]
-def instDecidableEmpEqImpl (xs : Array α) : Decidable (#[] = xs) :=
-  decidable_of_iff xs.isEmpty <| by rcases xs with ⟨⟨⟩⟩ <;> simp [Array.isEmpty]
-
-@[csimp]
-theorem instDecidableEqEmp_csimp : @instDecidableEqEmp = @instDecidableEqEmpImpl :=
-  Subsingleton.allEq _ _
-
-@[csimp]
-theorem instDecidableEmpEq_csimp : @instDecidableEmpEq = @instDecidableEmpEqImpl :=
-  Subsingleton.allEq _ _
+instance [DecidableEq α] : DecidableEq (Array α) :=
+  fun xs ys =>
+    match h:isEqv xs ys (fun a b => a = b) with
+    | true  => isTrue (eq_of_isEqv xs ys h)
+    | false => isFalse fun h' => by subst h'; rw [isEqv_self] at h; contradiction
 
 theorem beq_eq_decide [BEq α] (xs ys : Array α) :
     (xs == ys) = if h : xs.size = ys.size then

src/Init/Data/Array/Erase.lean

@@ -139,16 +139,25 @@ theorem eraseP_replicate {n : Nat} {a : α} {p : α → Bool} :
   simp only [← List.toArray_replicate, List.eraseP_toArray, List.eraseP_replicate]
   split <;> simp
 
+@[deprecated eraseP_replicate (since := "2025-03-18")]
+abbrev eraseP_mkArray := @eraseP_replicate
+
 @[simp] theorem eraseP_replicate_of_pos {n : Nat} {a : α} (h : p a) :
     (replicate n a).eraseP p = replicate (n - 1) a := by
   simp only [← List.toArray_replicate, List.eraseP_toArray]
   simp [h]
 
+@[deprecated eraseP_replicate_of_pos (since := "2025-03-18")]
+abbrev eraseP_mkArray_of_pos := @eraseP_replicate_of_pos
+
 @[simp] theorem eraseP_replicate_of_neg {n : Nat} {a : α} (h : ¬p a) :
     (replicate n a).eraseP p = replicate n a := by
   simp only [← List.toArray_replicate, List.eraseP_toArray]
   simp [h]
 
+@[deprecated eraseP_replicate_of_neg (since := "2025-03-18")]
+abbrev eraseP_mkArray_of_neg := @eraseP_replicate_of_neg
+
 theorem eraseP_eq_iff {p} {xs : Array α} :
     xs.eraseP p = ys ↔
       ((∀ a ∈ xs, ¬ p a) ∧ xs = ys) ∨
@@ -269,6 +278,9 @@ theorem erase_replicate [LawfulBEq α] {n : Nat} {a b : α} :
   simp only [List.erase_replicate, beq_iff_eq, List.toArray_replicate]
   split <;> simp
 
+@[deprecated erase_replicate (since := "2025-03-18")]
+abbrev erase_mkArray := @erase_replicate
+
 -- The arguments `a b` are explicit,
 -- so they can be specified to prevent `simp` repeatedly applying the lemma.
 @[grind =]
@@ -296,11 +308,17 @@ theorem erase_eq_iff [LawfulBEq α] {a : α} {xs : Array α} :
   simp only [← List.toArray_replicate, List.erase_toArray]
   simp
 
+@[deprecated erase_replicate_self (since := "2025-03-18")]
+abbrev erase_mkArray_self := @erase_replicate_self
+
 @[simp] theorem erase_replicate_ne [LawfulBEq α] {a b : α} (h : !b == a) :
     (replicate n a).erase b = replicate n a := by
   rw [erase_of_not_mem]
   simp_all
 
+@[deprecated erase_replicate_ne (since := "2025-03-18")]
+abbrev erase_mkArray_ne := @erase_replicate_ne
+
 end erase
 
 /-! ### eraseIdxIfInBounds -/
@@ -389,6 +407,9 @@ theorem eraseIdx_append_of_size_le {xs : Array α} {k : Nat} (hk : xs.size ≤ k
   simp at hk
   simp [List.eraseIdx_append_of_length_le, *]
 
+@[deprecated eraseIdx_append_of_size_le (since := "2025-06-11")]
+abbrev eraseIdx_append_of_length_le := @eraseIdx_append_of_size_le
+
 @[grind =]
 theorem eraseIdx_append {xs ys : Array α} (h : k < (xs ++ ys).size) :
     eraseIdx (xs ++ ys) k =
@@ -408,6 +429,9 @@ theorem eraseIdx_replicate {n : Nat} {a : α} {k : Nat} {h} :
   simp only [← List.toArray_replicate, List.eraseIdx_toArray]
   simp [List.eraseIdx_replicate, h]
 
+@[deprecated eraseIdx_replicate (since := "2025-03-18")]
+abbrev eraseIdx_mkArray := @eraseIdx_replicate
+
 theorem mem_eraseIdx_iff_getElem {x : α} {xs : Array α} {k} {h} : x ∈ xs.eraseIdx k h ↔ ∃ i w, i ≠ k ∧ xs[i]'w = x := by
   rcases xs with ⟨xs⟩
   simp [List.mem_eraseIdx_iff_getElem, *]

src/Init/Data/Array/Extract.lean

@@ -200,7 +200,7 @@ theorem getElem?_extract_of_succ {as : Array α} {j : Nat} :
   simp [getElem?_extract]
   omega
 
-@[simp] theorem extract_extract {as : Array α} {i j k l : Nat} :
+@[simp, grind =] theorem extract_extract {as : Array α} {i j k l : Nat} :
     (as.extract i j).extract k l = as.extract (i + k) (min (i + l) j) := by
   ext m h₁ h₂
   · simp
@@ -208,9 +208,6 @@ theorem getElem?_extract_of_succ {as : Array α} {j : Nat} :
   · simp only [size_extract] at h₁ h₂
     simp [Nat.add_assoc]
 
-grind_pattern extract_extract => (as.extract i j).extract k l where
-  as =/= #[]
-
 theorem extract_eq_empty_of_eq_empty {as : Array α} {i j : Nat} (h : as = #[]) :
     as.extract i j = #[] := by
   simp [h]
@@ -292,6 +289,9 @@ theorem extract_append_right {as bs : Array α} :
   · simp only [size_extract, size_replicate] at h₁ h₂
     simp only [getElem_extract, getElem_replicate]
 
+@[deprecated extract_replicate (since := "2025-03-18")]
+abbrev extract_mkArray := @extract_replicate
+
 theorem extract_eq_extract_right {as : Array α} {i j j' : Nat} :
     as.extract i j = as.extract i j' ↔ min (j - i) (as.size - i) = min (j' - i) (as.size - i) := by
   rcases as with ⟨as⟩
@@ -409,6 +409,8 @@ theorem popWhile_append {xs ys : Array α} :
   rcases ys with ⟨ys⟩
   simp only [List.append_toArray, List.popWhile_toArray, List.reverse_append, List.dropWhile_append,
     List.isEmpty_iff, List.isEmpty_toArray, List.isEmpty_reverse]
+  -- Why do these not fire with `simp`?
+  rw [List.popWhile_toArray, List.isEmpty_toArray, List.isEmpty_reverse]
   split
   · rfl
   · simp
@@ -427,20 +429,32 @@ theorem popWhile_append {xs ys : Array α} :
     (replicate n a).takeWhile p = (replicate n a).filter p := by
   simp [← List.toArray_replicate]
 
+@[deprecated takeWhile_replicate_eq_filter (since := "2025-03-18")]
+abbrev takeWhile_mkArray_eq_filter := @takeWhile_replicate_eq_filter
+
 theorem takeWhile_replicate {p : α → Bool} :
     (replicate n a).takeWhile p = if p a then replicate n a else #[] := by
   simp [takeWhile_replicate_eq_filter, filter_replicate]
 
+@[deprecated takeWhile_replicate (since := "2025-03-18")]
+abbrev takeWhile_mkArray := @takeWhile_replicate
+
 @[simp] theorem popWhile_replicate_eq_filter_not {p : α → Bool} :
     (replicate n a).popWhile p = (replicate n a).filter (fun a => !p a) := by
   simp [← List.toArray_replicate, ← List.filter_reverse]
 
+@[deprecated popWhile_replicate_eq_filter_not (since := "2025-03-18")]
+abbrev popWhile_mkArray_eq_filter_not := @popWhile_replicate_eq_filter_not
+
 theorem popWhile_replicate {p : α → Bool} :
     (replicate n a).popWhile p = if p a then #[] else replicate n a := by
   simp only [popWhile_replicate_eq_filter_not, size_replicate, filter_replicate, Bool.not_eq_eq_eq_not,
     Bool.not_true]
   split <;> simp_all
 
+@[deprecated popWhile_replicate (since := "2025-03-18")]
+abbrev popWhile_mkArray := @popWhile_replicate
+
 theorem extract_takeWhile {as : Array α} {i : Nat} :
     (as.takeWhile p).extract 0 i = (as.extract 0 i).takeWhile p := by
   rcases as with ⟨as⟩

src/Init/Data/Array/Find.lean

@@ -129,19 +129,31 @@ theorem getElem_zero_flatten {xss : Array (Array α)} (h) :
 theorem findSome?_replicate : findSome? f (replicate n a) = if n = 0 then none else f a := by
   simp [← List.toArray_replicate, List.findSome?_replicate]
 
+@[deprecated findSome?_replicate (since := "2025-03-18")]
+abbrev findSome?_mkArray := @findSome?_replicate
+
 @[simp] theorem findSome?_replicate_of_pos (h : 0 < n) : findSome? f (replicate n a) = f a := by
   simp [findSome?_replicate, Nat.ne_of_gt h]
 
+@[deprecated findSome?_replicate_of_pos (since := "2025-03-18")]
+abbrev findSome?_mkArray_of_pos := @findSome?_replicate_of_pos
+
 -- Argument is unused, but used to decide whether `simp` should unfold.
 @[simp] theorem findSome?_replicate_of_isSome (_ : (f a).isSome) :
    findSome? f (replicate n a) = if n = 0 then none else f a := by
   simp [findSome?_replicate]
 
+@[deprecated findSome?_replicate_of_isSome (since := "2025-03-18")]
+abbrev findSome?_mkArray_of_isSome := @findSome?_replicate_of_isSome
+
 @[simp] theorem findSome?_replicate_of_isNone (h : (f a).isNone) :
     findSome? f (replicate n a) = none := by
   rw [Option.isNone_iff_eq_none] at h
   simp [findSome?_replicate, h]
 
+@[deprecated findSome?_replicate_of_isNone (since := "2025-03-18")]
+abbrev findSome?_mkArray_of_isNone := @findSome?_replicate_of_isNone
+
 /-! ### find? -/
 
 @[simp, grind =] theorem find?_empty : find? p #[] = none := rfl
@@ -159,6 +171,9 @@ theorem find?_singleton {a : α} {p : α → Bool} :
     findRev? p (xs.push a) = findRev? p xs := by
   cases xs; simp [h]
 
+@[deprecated findRev?_push_of_neg (since := "2025-06-12")]
+abbrev findRev?_cons_of_neg := @findRev?_push_of_neg
+
 @[grind =]
 theorem finRev?_push {xs : Array α} :
     findRev? p (xs.push a) = (Option.guard p a).or (xs.findRev? p) := by
@@ -168,6 +183,9 @@ theorem finRev?_push {xs : Array α} :
   · rw [findRev?_push_of_pos, Option.guard_eq_some_iff.mpr ⟨rfl, h⟩]
     all_goals simp [h]
 
+@[deprecated finRev?_push (since := "2025-06-12")]
+abbrev findRev?_cons := @finRev?_push
+
 @[simp, grind =] theorem find?_eq_none : find? p xs = none ↔ ∀ x ∈ xs, ¬ p x := by
   cases xs; simp
 
@@ -300,10 +318,16 @@ theorem find?_replicate :
     find? p (replicate n a) = if p a then some a else none := by
   simp [find?_replicate, Nat.ne_of_gt h]
 
+@[deprecated find?_replicate_of_size_pos (since := "2025-03-18")]
+abbrev find?_mkArray_of_length_pos := @find?_replicate_of_size_pos
+
 @[simp] theorem find?_replicate_of_pos (h : p a) :
     find? p (replicate n a) = if n = 0 then none else some a := by
   simp [find?_replicate, h]
 
+@[deprecated find?_replicate_of_pos (since := "2025-03-18")]
+abbrev find?_mkArray_of_pos := @find?_replicate_of_pos
+
 @[simp] theorem find?_replicate_of_neg (h : ¬ p a) : find? p (replicate n a) = none := by
   simp [find?_replicate, h]
 
@@ -559,6 +583,9 @@ theorem findIdx?_flatten {xss : Array (Array α)} {p : α → Bool} :
   simp only [List.findIdx?_toArray]
   simp
 
+@[deprecated findIdx?_replicate (since := "2025-03-18")]
+abbrev findIdx?_mkArray := @findIdx?_replicate
+
 theorem findIdx?_eq_findSome?_zipIdx {xs : Array α} {p : α → Bool} :
     xs.findIdx? p = xs.zipIdx.findSome? fun ⟨a, i⟩ => if p a then some i else none := by
   rcases xs with ⟨xs⟩

src/Init/Data/Array/GetLit.lean

@@ -50,6 +50,6 @@ where
   getLit_eq (xs : Array α) (i : Nat) (h₁ : xs.size = n) (h₂ : i < n) : xs.getLit i h₁ h₂ = getElem xs.toList i ((id (α := xs.toList.length = n) h₁) ▸ h₂) :=
     rfl
   go (i : Nat) (hi : i ≤ xs.size) : toListLitAux xs n hsz i hi (xs.toList.drop i) = xs.toList := by
-    induction i <;> simp only [List.drop, toListLitAux, getLit_eq, List.getElem_cons_drop, *]
+    induction i <;> simp only [List.drop, toListLitAux, getLit_eq, List.getElem_cons_drop_succ_eq_drop, *]
 
 end Array

src/Init/Data/Array/InsertIdx.lean

@@ -53,6 +53,11 @@ theorem eraseIdx_insertIdx_self {i : Nat} {xs : Array α} (h : i ≤ xs.size) :
   rcases xs with ⟨xs⟩
   simp_all
 
+@[deprecated eraseIdx_insertIdx_self (since := "2025-06-15")]
+theorem eraseIdx_insertIdx {i : Nat} {xs : Array α} (h : i ≤ xs.size) :
+    (xs.insertIdx i a).eraseIdx i (by simp; omega) = xs := by
+  simp [eraseIdx_insertIdx_self]
+
 theorem insertIdx_eraseIdx_of_ge {as : Array α}
     (w₁ : i < as.size) (w₂ : j ≤ (as.eraseIdx i).size) (h : i ≤ j) :
     (as.eraseIdx i).insertIdx j a =

src/Init/Data/Array/Lemmas.lean

@@ -62,9 +62,6 @@ theorem eq_empty_of_size_eq_zero (h : xs.size = 0) : xs = #[] := by
   cases xs
   simp_all
 
-grind_pattern eq_empty_of_size_eq_zero => xs.size where
-  guard xs.size = 0
-
 theorem ne_empty_of_size_eq_add_one (h : xs.size = n + 1) : xs ≠ #[] := by
   cases xs
   simpa using List.ne_nil_of_length_eq_add_one h
@@ -115,8 +112,7 @@ theorem none_eq_getElem?_iff {xs : Array α} {i : Nat} : none = xs[i]? ↔ xs.si
 theorem getElem?_eq_none {xs : Array α} (h : xs.size ≤ i) : xs[i]? = none := by
   simp [h]
 
-grind_pattern Array.getElem?_eq_none => xs.size, xs[i]? where
-  guard xs.size ≤ i
+grind_pattern Array.getElem?_eq_none => xs.size, xs[i]?
 
 @[simp] theorem getElem?_eq_getElem {xs : Array α} {i : Nat} (h : i < xs.size) : xs[i]? = some xs[i] :=
   getElem?_pos ..
@@ -249,13 +245,12 @@ theorem back_eq_of_push_eq {a b : α} {xs ys : Array α} (h : xs.push a = ys.pus
   replace h := List.append_inj_right' h (by simp)
   simpa using h
 
-theorem push_eq_push {a b : α} {xs ys : Array α} : xs.push a = ys.push b ↔ a = b ∧ xs = ys := by
+theorem pop_eq_of_push_eq {a b : α} {xs ys : Array α} (h : xs.push a = ys.push b) : xs = ys := by
   cases xs
   cases ys
-  simp [And.comm]
-
-theorem pop_eq_of_push_eq {a b : α} {xs ys : Array α} (h : xs.push a = ys.push b) : xs = ys :=
-  (push_eq_push.1 h).2
+  simp at h
+  replace h := List.append_inj_left' h (by simp)
+  simp [h]
 
 theorem push_inj_left {a : α} {xs ys : Array α} : xs.push a = ys.push a ↔ xs = ys :=
   ⟨pop_eq_of_push_eq, fun h => by simp [h]⟩
@@ -263,6 +258,15 @@ theorem push_inj_left {a : α} {xs ys : Array α} : xs.push a = ys.push a ↔ xs
 theorem push_inj_right {a b : α} {xs : Array α} : xs.push a = xs.push b ↔ a = b :=
   ⟨back_eq_of_push_eq, fun h => by simp [h]⟩
 
+theorem push_eq_push {a b : α} {xs ys : Array α} : xs.push a = ys.push b ↔ a = b ∧ xs = ys := by
+  constructor
+  · intro h
+    exact ⟨back_eq_of_push_eq h, pop_eq_of_push_eq h⟩
+  · rintro ⟨rfl, rfl⟩
+    rfl
+
+theorem push_eq_append_singleton {as : Array α} {x : α} : as.push x = as ++ #[x] := rfl
+
 theorem exists_push_of_ne_empty {xs : Array α} (h : xs ≠ #[]) :
     ∃ (ys : Array α) (a : α), xs = ys.push a := by
   rcases xs with ⟨xs⟩
@@ -313,23 +317,41 @@ theorem singleton_inj : #[a] = #[b] ↔ a = b := by
 @[simp, grind =] theorem size_replicate {n : Nat} {v : α} : (replicate n v).size = n :=
   List.length_replicate ..
 
+@[deprecated size_replicate (since := "2025-03-18")]
+abbrev size_mkArray := @size_replicate
+
 @[simp] theorem toList_replicate : (replicate n a).toList = List.replicate n a := by
   simp only [replicate]
 
+@[deprecated toList_replicate (since := "2025-03-18")]
+abbrev toList_mkArray := @toList_replicate
+
 @[simp, grind =] theorem replicate_zero : replicate 0 a = #[] := rfl
 
+@[deprecated replicate_zero (since := "2025-03-18")]
+abbrev mkArray_zero := @replicate_zero
+
 @[grind =]
 theorem replicate_succ : replicate (n + 1) a = (replicate n a).push a := by
   apply toList_inj.1
   simp [List.replicate_succ']
 
+@[deprecated replicate_succ (since := "2025-03-18")]
+abbrev mkArray_succ := @replicate_succ
+
 @[simp, grind =] theorem getElem_replicate {n : Nat} {v : α} {i : Nat} (h : i < (replicate n v).size) :
     (replicate n v)[i] = v := by simp [← getElem_toList]
 
+@[deprecated getElem_replicate (since := "2025-03-18")]
+abbrev getElem_mkArray := @getElem_replicate
+
 @[grind =] theorem getElem?_replicate {n : Nat} {v : α} {i : Nat} :
     (replicate n v)[i]? = if i < n then some v else none := by
   simp [getElem?_def]
 
+@[deprecated getElem?_replicate (since := "2025-03-18")]
+abbrev getElem?_mkArray := @getElem?_replicate
+
 /-! ### mem -/
 
 @[grind ←]
@@ -813,11 +835,6 @@ theorem contains_eq_true_of_mem [BEq α] [ReflBEq α] {a : α} {as : Array α} (
 theorem elem_iff [BEq α] [LawfulBEq α] {a : α} {xs : Array α} :
     elem a xs = true ↔ a ∈ xs := ⟨mem_of_contains_eq_true, contains_eq_true_of_mem⟩
 
-@[grind =]
-theorem contains_iff_mem [BEq α] [LawfulBEq α] {a : α} {xs : Array α} :
-    xs.contains a = true ↔ a ∈ xs := ⟨mem_of_contains_eq_true, contains_eq_true_of_mem⟩
-
-@[deprecated contains_iff_mem (since := "2025-10-26")]
 theorem contains_iff [BEq α] [LawfulBEq α] {a : α} {xs : Array α} :
     xs.contains a = true ↔ a ∈ xs := ⟨mem_of_contains_eq_true, contains_eq_true_of_mem⟩
 
@@ -1057,6 +1074,12 @@ theorem mem_or_eq_of_mem_setIfInBounds
   cases xs
   simp
 
+@[deprecated beq_empty_eq (since := "2025-04-04")]
+abbrev beq_empty_iff := @beq_empty_eq
+
+@[deprecated empty_beq_eq (since := "2025-04-04")]
+abbrev empty_beq_iff := @empty_beq_eq
+
 @[simp, grind =] theorem push_beq_push [BEq α] {a b : α} {xs ys : Array α} :
     (xs.push a == ys.push b) = (xs == ys && a == b) := by
   cases xs
@@ -1077,6 +1100,9 @@ theorem size_eq_of_beq [BEq α] {xs ys : Array α} (h : xs == ys) : xs.size = ys
     rw [Bool.eq_iff_iff]
     simp +contextual
 
+@[deprecated replicate_beq_replicate (since := "2025-03-18")]
+abbrev mkArray_beq_mkArray := @replicate_beq_replicate
+
 private theorem beq_of_beq_singleton [BEq α] {a b : α} : #[a] == #[b] → a == b := by
   intro h
   have : isEqv #[a] #[b] BEq.beq = true := h
@@ -1140,7 +1166,7 @@ where
   aux (i bs) :
       mapM.map f xs i bs = (xs.toList.drop i).foldlM (fun bs a => bs.push <$> f a) bs := by
     unfold mapM.map; split
-    · rw [← List.getElem_cons_drop ‹_›]
+    · rw [← List.getElem_cons_drop_succ_eq_drop ‹_›]
       simp only [aux (i + 1), map_eq_pure_bind, List.foldlM_cons, bind_assoc,
         pure_bind]
       rfl
@@ -1632,15 +1658,12 @@ theorem filterMap_eq_filter {p : α → Bool} (w : stop = as.size) :
   cases as
   simp
 
+@[grind =]
 theorem filterMap_filterMap {f : α → Option β} {g : β → Option γ} {xs : Array α} :
     filterMap g (filterMap f xs) = filterMap (fun x => (f x).bind g) xs := by
   cases xs
   simp [List.filterMap_filterMap]
 
-grind_pattern filterMap_filterMap => filterMap g (filterMap f xs) where
-  f =/= some
-  g =/= some
-
 @[grind =]
 theorem map_filterMap {f : α → Option β} {g : β → γ} {xs : Array α} :
     map g (filterMap f xs) = filterMap (fun x => (f x).map g) xs := by
@@ -1695,6 +1718,9 @@ theorem forall_none_of_filterMap_eq_empty (h : filterMap f xs = #[]) : ∀ x ∈
   cases xs
   simp
 
+@[deprecated filterMap_eq_empty_iff (since := "2025-04-04")]
+abbrev filterMap_eq_nil_iff := @filterMap_eq_empty_iff
+
 theorem filterMap_eq_push_iff {f : α → Option β} {xs : Array α} {ys : Array β} {b : β} :
     filterMap f xs = ys.push b ↔ ∃ as a bs,
       xs = as.push a ++ bs ∧ filterMap f as = ys ∧ f a = some b ∧ (∀ x, x ∈ bs → f x = none) := by
@@ -1762,6 +1788,11 @@ theorem toArray_append {xs : List α} {ys : Array α} :
 
 theorem singleton_eq_toArray_singleton {a : α} : #[a] = [a].toArray := rfl
 
+@[deprecated empty_append (since := "2025-05-26")]
+theorem empty_append_fun : ((#[] : Array α) ++ ·) = id := by
+  funext ⟨l⟩
+  simp
+
 @[simp, grind =] theorem mem_append {a : α} {xs ys : Array α} : a ∈ xs ++ ys ↔ a ∈ xs ∨ a ∈ ys := by
   simp only [mem_def, toList_append, List.mem_append]
 
@@ -1852,9 +1883,6 @@ theorem getElem_of_append {xs ys zs : Array α} (eq : xs = ys.push a ++ zs) (h :
 
 theorem push_eq_append {a : α} {as : Array α} : as.push a = as ++ #[a] := rfl
 
-@[deprecated push_eq_append (since := "2025-10-26")]
-theorem push_eq_append_singleton {as : Array α} {x : α} : as.push x = as ++ #[x] := rfl
-
 theorem append_inj {xs₁ xs₂ ys₁ ys₂ : Array α} (h : xs₁ ++ ys₁ = xs₂ ++ ys₂) (hl : xs₁.size = xs₂.size) :
     xs₁ = xs₂ ∧ ys₁ = ys₂ := by
   rcases xs₁ with ⟨s₁⟩
@@ -2055,22 +2083,11 @@ theorem append_eq_map_iff {f : α → β} :
   | nil => simp
   | cons as => induction as.toList <;> simp [*]
 
-@[simp] theorem flatten_toArray_map_toArray {L : List (List α)} :
+@[simp] theorem flatten_toArray_map {L : List (List α)} :
     (L.map List.toArray).toArray.flatten = L.flatten.toArray := by
   apply ext'
   simp [Function.comp_def]
 
-@[deprecated flatten_toArray_map_toArray (since := "2025-10-26")]
-theorem flatten_toArray_map {L : List (List α)} :
-    (L.map List.toArray).toArray.flatten = L.flatten.toArray := by
-  simp
-
-@[grind =]
-theorem flatten_map_toArray_toArray {L : List (List α)} :
-    (L.toArray.map List.toArray).flatten = L.flatten.toArray := by
-  simp
-
-@[deprecated flatten_map_toArray_toArray (since := "2025-10-26")]
 theorem flatten_map_toArray {L : List (List α)} :
     (L.toArray.map List.toArray).flatten = L.flatten.toArray := by
   simp
@@ -2117,33 +2134,32 @@ theorem forall_mem_flatten {p : α → Prop} {xss : Array (Array α)} :
 
 theorem flatten_eq_flatMap {xss : Array (Array α)} : flatten xss = xss.flatMap id := by
   induction xss using array₂_induction
-  rw [flatten_toArray_map_toArray, List.flatten_eq_flatMap]
+  rw [flatten_toArray_map, List.flatten_eq_flatMap]
   simp [List.flatMap_map]
 
 @[simp, grind _=_] theorem map_flatten {f : α → β} {xss : Array (Array α)} :
     (flatten xss).map f = (map (map f) xss).flatten := by
   induction xss using array₂_induction with
   | of xss =>
-    simp only [flatten_toArray_map_toArray, List.map_toArray, List.map_flatten, List.map_map,
+    simp only [flatten_toArray_map, List.map_toArray, List.map_flatten, List.map_map,
       Function.comp_def]
-    rw [← Function.comp_def, ← List.map_map, flatten_toArray_map_toArray]
+    rw [← Function.comp_def, ← List.map_map, flatten_toArray_map]
 
 @[simp, grind =] theorem filterMap_flatten {f : α → Option β} {xss : Array (Array α)} {stop : Nat} (w : stop = xss.flatten.size) :
     filterMap f (flatten xss) 0 stop = flatten (map (filterMap f) xss) := by
   subst w
   induction xss using array₂_induction
-  simp only [flatten_toArray_map_toArray, List.size_toArray, List.length_flatten,
-    List.filterMap_toArray', List.filterMap_flatten, List.map_toArray, List.map_map,
-    Function.comp_def]
-  rw [← Function.comp_def, ← List.map_map, flatten_toArray_map_toArray]
+  simp only [flatten_toArray_map, List.size_toArray, List.length_flatten, List.filterMap_toArray',
+    List.filterMap_flatten, List.map_toArray, List.map_map, Function.comp_def]
+  rw [← Function.comp_def, ← List.map_map, flatten_toArray_map]
 
 @[simp, grind =] theorem filter_flatten {p : α → Bool} {xss : Array (Array α)} {stop : Nat} (w : stop = xss.flatten.size) :
     filter p (flatten xss) 0 stop = flatten (map (filter p) xss) := by
   subst w
   induction xss using array₂_induction
-  simp only [flatten_toArray_map_toArray, List.size_toArray, List.length_flatten,
-    List.filter_toArray', List.filter_flatten, List.map_toArray, List.map_map, Function.comp_def]
-  rw [← Function.comp_def, ← List.map_map, flatten_toArray_map_toArray]
+  simp only [flatten_toArray_map, List.size_toArray, List.length_flatten, List.filter_toArray',
+    List.filter_flatten, List.map_toArray, List.map_map, Function.comp_def]
+  rw [← Function.comp_def, ← List.map_map, flatten_toArray_map]
 
 theorem flatten_filter_not_isEmpty {xss : Array (Array α)} :
     flatten (xss.filter fun xs => !xs.isEmpty) = xss.flatten := by
@@ -2166,23 +2182,23 @@ theorem flatten_filter_ne_empty [DecidablePred fun xs : Array α => xs ≠ #[]]
   induction xss using array₂_induction
   rcases xs with ⟨l⟩
   have this : [l.toArray] = [l].map List.toArray := by simp
-  simp only [List.push_toArray, flatten_toArray_map_toArray, List.append_toArray]
-  rw [this, ← List.map_append, flatten_toArray_map_toArray]
+  simp only [List.push_toArray, flatten_toArray_map, List.append_toArray]
+  rw [this, ← List.map_append, flatten_toArray_map]
   simp
 
 theorem flatten_flatten {xss : Array (Array (Array α))} : flatten (flatten xss) = flatten (map flatten xss) := by
   induction xss using array₃_induction with
   | of xss =>
-    rw [flatten_toArray_map_toArray]
+    rw [flatten_toArray_map]
     have : (xss.map (fun xs => xs.map List.toArray)).flatten = xss.flatten.map List.toArray := by
       induction xss with
       | nil => simp
       | cons xs xss ih =>
         simp only [List.map_cons, List.flatten_cons, ih, List.map_append]
-    rw [this, flatten_toArray_map_toArray, List.flatten_flatten, ← List.map_toArray, Array.map_map,
+    rw [this, flatten_toArray_map, List.flatten_flatten, ← List.map_toArray, Array.map_map,
       ← List.map_toArray, map_map, Function.comp_def]
-    simp only [Function.comp_apply, flatten_toArray_map_toArray]
-    rw [List.map_toArray, ← Function.comp_def, ← List.map_map, flatten_toArray_map_toArray]
+    simp only [Function.comp_apply, flatten_toArray_map]
+    rw [List.map_toArray, ← Function.comp_def, ← List.map_map, flatten_toArray_map]
 
 theorem flatten_eq_push_iff {xss : Array (Array α)} {ys : Array α} {y : α} :
     xss.flatten = ys.push y ↔
@@ -2191,13 +2207,13 @@ theorem flatten_eq_push_iff {xss : Array (Array α)} {ys : Array α} {y : α} :
   induction xss using array₂_induction with
   | of xs =>
     rcases ys with ⟨ys⟩
-    rw [flatten_toArray_map_toArray, List.push_toArray, mk.injEq, List.flatten_eq_append_iff]
+    rw [flatten_toArray_map, List.push_toArray, mk.injEq, List.flatten_eq_append_iff]
     constructor
     · rintro (⟨as, bs, rfl, rfl, h⟩ | ⟨as, bs, c, cs, ds, rfl, rfl, h⟩)
       · rw [List.singleton_eq_flatten_iff] at h
         obtain ⟨xs, ys, rfl, h₁, h₂⟩ := h
         exact ⟨((as ++ xs).map List.toArray).toArray, #[], (ys.map List.toArray).toArray, by simp,
-          by simpa using h₂, by rw [flatten_toArray_map_toArray]; simpa⟩
+          by simpa using h₂, by rw [flatten_toArray_map]; simpa⟩
       · rw [List.singleton_eq_append_iff] at h
         obtain (⟨h₁, h₂⟩ | ⟨h₁, h₂⟩) := h
         · simp at h₁
@@ -2230,8 +2246,8 @@ theorem push_eq_flatten_iff {xss : Array (Array α)} {ys : Array α} {y : α} :
 --           zs = cs ++ ds.flatten := by sorry
 
 
-/-- Two arrays of arrays are equal iff their flattens coincide, as well as the sizes of the
-arrays. -/
+/-- Two arrays of subarrays are equal iff their flattens coincide, as well as the sizes of the
+subarrays. -/
 theorem eq_iff_flatten_eq {xss₁ xss₂ : Array (Array α)} :
     xss₁ = xss₂ ↔ xss₁.flatten = xss₂.flatten ∧ map size xss₁ = map size xss₂ := by
   cases xss₁ using array₂_induction with
@@ -2242,12 +2258,18 @@ theorem eq_iff_flatten_eq {xss₁ xss₂ : Array (Array α)} :
       rw [List.map_inj_right]
       simp +contextual
 
+theorem flatten_toArray_map_toArray {xss : List (List α)} :
+    (xss.map List.toArray).toArray.flatten = xss.flatten.toArray := by
+  simp
+
 /-! ### flatMap -/
 
 theorem flatMap_def {xs : Array α} {f : α → Array β} : xs.flatMap f = flatten (map f xs) := by
   rcases xs with ⟨l⟩
   simp [flatten_toArray, Function.comp_def, List.flatMap_def]
 
+@[simp, grind =] theorem flatMap_empty {β} {f : α → Array β} : (#[] : Array α).flatMap f = #[] := rfl
+
 theorem flatMap_toList {xs : Array α} {f : α → List β} :
     xs.toList.flatMap f = (xs.flatMap (fun a => (f a).toArray)).toList := by
   rcases xs with ⟨l⟩
@@ -2258,7 +2280,6 @@ theorem flatMap_toList {xs : Array α} {f : α → List β} :
   rcases xs with ⟨l⟩
   simp
 
-@[deprecated List.flatMap_toArray_cons (since := "2025-10-29")]
 theorem flatMap_toArray_cons {β} {f : α → Array β} {a : α} {as : List α} :
     (a :: as).toArray.flatMap f = f a ++ as.toArray.flatMap f := by
   simp [flatMap]
@@ -2269,7 +2290,6 @@ theorem flatMap_toArray_cons {β} {f : α → Array β} {a : α} {as : List α}
   intro cs
   induction as generalizing cs <;> simp_all
 
-@[deprecated List.flatMap_toArray (since := "2025-10-29")]
 theorem flatMap_toArray {β} {f : α → Array β} {as : List α} :
     as.toArray.flatMap f = (as.flatMap (fun a => (f a).toList)).toArray := by
   simp
@@ -2370,44 +2390,77 @@ theorem flatMap_eq_foldl {f : α → Array β} {xs : Array α} :
 
 @[simp] theorem replicate_one : replicate 1 a = #[a] := rfl
 
+@[deprecated replicate_one (since := "2025-03-18")]
+abbrev mkArray_one := @replicate_one
+
 /-- Variant of `replicate_succ` that prepends `a` at the beginning of the array. -/
 theorem replicate_succ' : replicate (n + 1) a = #[a] ++ replicate n a := by
   apply Array.ext'
   simp [List.replicate_succ]
 
+@[deprecated replicate_succ' (since := "2025-03-18")]
+abbrev mkArray_succ' := @replicate_succ'
+
 @[simp, grind =] theorem mem_replicate {a b : α} {n} : b ∈ replicate n a ↔ n ≠ 0 ∧ b = a := by
   unfold replicate
   simp only [List.mem_toArray, List.mem_replicate]
 
+@[deprecated mem_replicate (since := "2025-03-18")]
+abbrev mem_mkArray := @mem_replicate
+
 @[grind →] theorem eq_of_mem_replicate {a b : α} {n} (h : b ∈ replicate n a) : b = a := (mem_replicate.1 h).2
 
+@[deprecated eq_of_mem_mkArray (since := "2025-03-18")]
+abbrev eq_of_mem_mkArray := @eq_of_mem_replicate
+
 theorem forall_mem_replicate {p : α → Prop} {a : α} {n} :
     (∀ b, b ∈ replicate n a → p b) ↔ n = 0 ∨ p a := by
   cases n <;> simp [mem_replicate]
 
+@[deprecated forall_mem_replicate (since := "2025-03-18")]
+abbrev forall_mem_mkArray := @forall_mem_replicate
+
 @[simp] theorem replicate_succ_ne_empty {n : Nat} {a : α} : replicate (n+1) a ≠ #[] := by
   simp [replicate_succ]
 
+@[deprecated replicate_succ_ne_empty (since := "2025-03-18")]
+abbrev mkArray_succ_ne_empty := @replicate_succ_ne_empty
+
 @[simp] theorem replicate_eq_empty_iff {n : Nat} {a : α} : replicate n a = #[] ↔ n = 0 := by
   cases n <;> simp
 
+@[deprecated replicate_eq_empty_iff (since := "2025-03-18")]
+abbrev mkArray_eq_empty_iff := @replicate_eq_empty_iff
+
 @[simp] theorem replicate_inj : replicate n a = replicate m b ↔ n = m ∧ (n = 0 ∨ a = b) := by
   rw [← toList_inj]
   simp
 
+@[deprecated replicate_inj (since := "2025-03-18")]
+abbrev mkArray_inj := @replicate_inj
+
 theorem eq_replicate_of_mem {a : α} {xs : Array α} (h : ∀ (b) (_ : b ∈ xs), b = a) : xs = replicate xs.size a := by
   rw [← toList_inj]
   simpa using List.eq_replicate_of_mem (by simpa using h)
 
+@[deprecated eq_replicate_of_mem (since := "2025-03-18")]
+abbrev eq_mkArray_of_mem := @eq_replicate_of_mem
+
 theorem eq_replicate_iff {a : α} {n} {xs : Array α} :
     xs = replicate n a ↔ xs.size = n ∧ ∀ (b) (_ : b ∈ xs), b = a := by
   rw [← toList_inj]
   simpa using List.eq_replicate_iff (l := xs.toList)
 
+@[deprecated eq_replicate_iff (since := "2025-03-18")]
+abbrev eq_mkArray_iff := @eq_replicate_iff
+
 theorem map_eq_replicate_iff {xs : Array α} {f : α → β} {b : β} :
     xs.map f = replicate xs.size b ↔ ∀ x ∈ xs, f x = b := by
   simp [eq_replicate_iff]
 
+@[deprecated map_eq_replicate_iff (since := "2025-03-18")]
+abbrev map_eq_mkArray_iff := @map_eq_replicate_iff
+
 @[simp] theorem map_const {xs : Array α} {b : β} : map (Function.const α b) xs = replicate xs.size b :=
   map_eq_replicate_iff.mpr fun _ _ => rfl
 
@@ -2424,86 +2477,143 @@ theorem map_const' {xs : Array α} {b : β} : map (fun _ => b) xs = replicate xs
   apply Array.ext'
   simp
 
+@[deprecated set_replicate_self (since := "2025-03-18")]
+abbrev set_mkArray_self := @set_replicate_self
+
 @[simp] theorem setIfInBounds_replicate_self : (replicate n a).setIfInBounds i a = replicate n a := by
   apply Array.ext'
   simp
 
+@[deprecated setIfInBounds_replicate_self (since := "2025-03-18")]
+abbrev setIfInBounds_mkArray_self := @setIfInBounds_replicate_self
+
 @[simp] theorem replicate_append_replicate : replicate n a ++ replicate m a = replicate (n + m) a := by
   apply Array.ext'
   simp
 
+@[deprecated replicate_append_replicate (since := "2025-03-18")]
+abbrev mkArray_append_mkArray := @replicate_append_replicate
+
 theorem append_eq_replicate_iff {xs ys : Array α} {a : α} :
     xs ++ ys = replicate n a ↔
       xs.size + ys.size = n ∧ xs = replicate xs.size a ∧ ys = replicate ys.size a := by
   simp [← toList_inj, List.append_eq_replicate_iff]
 
+@[deprecated append_eq_replicate_iff (since := "2025-03-18")]
+abbrev append_eq_mkArray_iff := @append_eq_replicate_iff
+
 theorem replicate_eq_append_iff {xs ys : Array α} {a : α} :
     replicate n a = xs ++ ys ↔
       xs.size + ys.size = n ∧ xs = replicate xs.size a ∧ ys = replicate ys.size a := by
   rw [eq_comm, append_eq_replicate_iff]
 
+@[deprecated replicate_eq_append_iff (since := "2025-03-18")]
+abbrev replicate_eq_mkArray_iff := @replicate_eq_append_iff
+
 @[simp] theorem map_replicate : (replicate n a).map f = replicate n (f a) := by
   apply Array.ext'
   simp
 
+@[deprecated map_replicate (since := "2025-03-18")]
+abbrev map_mkArray := @map_replicate
+
 @[grind =] theorem filter_replicate (w : stop = n) :
     (replicate n a).filter p 0 stop = if p a then replicate n a else #[] := by
   apply Array.ext'
   simp only [w]
   split <;> simp_all
 
+@[deprecated filter_replicate (since := "2025-03-18")]
+abbrev filter_mkArray := @filter_replicate
+
 @[simp] theorem filter_replicate_of_pos (w : stop = n) (h : p a) :
     (replicate n a).filter p 0 stop = replicate n a := by
   simp [filter_replicate, h, w]
 
+@[deprecated filter_replicate_of_pos (since := "2025-03-18")]
+abbrev filter_mkArray_of_pos := @filter_replicate_of_pos
+
 @[simp] theorem filter_replicate_of_neg (w : stop = n) (h : ¬ p a) :
     (replicate n a).filter p 0 stop = #[] := by
   simp [filter_replicate, h, w]
 
+@[deprecated filter_replicate_of_neg (since := "2025-03-18")]
+abbrev filter_mkArray_of_neg := @filter_replicate_of_neg
+
 theorem filterMap_replicate {f : α → Option β} (w : stop = n := by simp) :
     (replicate n a).filterMap f 0 stop = match f a with | none => #[] | .some b => replicate n b := by
   apply Array.ext'
   simp only [w, size_replicate, toList_filterMap', toList_replicate, List.filterMap_replicate]
   split <;> simp_all
 
+@[deprecated filterMap_replicate (since := "2025-03-18")]
+abbrev filterMap_mkArray := @filterMap_replicate
+
 -- This is not a useful `simp` lemma because `b` is unknown.
 theorem filterMap_replicate_of_some {f : α → Option β} (h : f a = some b) :
     (replicate n a).filterMap f = replicate n b := by
   simp [filterMap_replicate, h]
 
+@[deprecated filterMap_replicate_of_some (since := "2025-03-18")]
+abbrev filterMap_mkArray_of_some := @filterMap_replicate_of_some
+
 @[simp] theorem filterMap_replicate_of_isSome {f : α → Option β} (h : (f a).isSome) :
     (replicate n a).filterMap f = replicate n (Option.get _ h) := by
   match w : f a, h with
   | some b, _ => simp [filterMap_replicate, w]
 
+@[deprecated filterMap_replicate_of_isSome (since := "2025-03-18")]
+abbrev filterMap_mkArray_of_isSome := @filterMap_replicate_of_isSome
+
 @[simp] theorem filterMap_replicate_of_none {f : α → Option β} (h : f a = none) :
     (replicate n a).filterMap f = #[] := by
   simp [filterMap_replicate, h]
 
+@[deprecated filterMap_replicate_of_none (since := "2025-03-18")]
+abbrev filterMap_mkArray_of_none := @filterMap_replicate_of_none
+
 @[simp] theorem flatten_replicate_empty : (replicate n (#[] : Array α)).flatten = #[] := by
   rw [← toList_inj]
   simp
 
+@[deprecated flatten_replicate_empty (since := "2025-03-18")]
+abbrev flatten_mkArray_empty := @flatten_replicate_empty
+
 @[simp] theorem flatten_replicate_singleton : (replicate n #[a]).flatten = replicate n a := by
   rw [← toList_inj]
   simp
 
+@[deprecated flatten_replicate_singleton (since := "2025-03-18")]
+abbrev flatten_mkArray_singleton := @flatten_replicate_singleton
+
 @[simp] theorem flatten_replicate_replicate : (replicate n (replicate m a)).flatten = replicate (n * m) a := by
   rw [← toList_inj]
   simp
 
+@[deprecated flatten_replicate_replicate (since := "2025-03-18")]
+abbrev flatten_mkArray_replicate := @flatten_replicate_replicate
+
 theorem flatMap_replicate {f : α → Array β} : (replicate n a).flatMap f = (replicate n (f a)).flatten := by
   rw [← toList_inj]
   simp [List.flatMap_replicate]
 
+@[deprecated flatMap_replicate (since := "2025-03-18")]
+abbrev flatMap_mkArray := @flatMap_replicate
+
 @[simp] theorem isEmpty_replicate : (replicate n a).isEmpty = decide (n = 0) := by
   rw [← List.toArray_replicate, List.isEmpty_toArray]
   simp
 
+@[deprecated isEmpty_replicate (since := "2025-03-18")]
+abbrev isEmpty_mkArray := @isEmpty_replicate
+
 @[simp] theorem sum_replicate_nat {n : Nat} {a : Nat} : (replicate n a).sum = n * a := by
   rw [← List.toArray_replicate, List.sum_toArray]
   simp
 
+@[deprecated sum_replicate_nat (since := "2025-03-18")]
+abbrev sum_mkArray_nat := @sum_replicate_nat
+
 /-! ### Preliminaries about `swap` needed for `reverse`. -/
 
 @[grind =]
@@ -2545,8 +2655,8 @@ theorem getElem?_swap {xs : Array α} {i j : Nat} (hi hj) {k : Nat} : (xs.swap i
         split <;> rename_i h₃
         · simp only [← h₃, Nat.not_le.2 (Nat.lt_succ_self _), Nat.le_refl, false_and]
           exact (List.getElem?_reverse' (Eq.trans (by simp +arith) h)).symm
-        simp only [Nat.succ_le_iff, Nat.lt_iff_le_and_ne.trans (and_iff_left h₃),
-          Nat.lt_succ_iff.symm.trans (Nat.lt_iff_le_and_ne.trans (and_iff_left (Ne.symm h₂)))]
+        simp only [Nat.succ_le, Nat.lt_iff_le_and_ne.trans (and_iff_left h₃),
+          Nat.lt_succ.symm.trans (Nat.lt_iff_le_and_ne.trans (and_iff_left (Ne.symm h₂)))]
     · rw [H]; split <;> rename_i h₂
       · cases Nat.le_antisymm (Nat.not_lt.1 h₁) (Nat.le_trans h₂.1 h₂.2)
         cases Nat.le_antisymm h₂.1 h₂.2
@@ -2561,7 +2671,7 @@ theorem getElem?_swap {xs : Array α} {i j : Nat} (hi hj) {k : Nat} : (xs.swap i
     split
     · rfl
     · rename_i h
-      simp only [← show k < _ + 1 ↔ _ from Nat.lt_succ_iff (n := xs.size - 1), this, Nat.zero_le,
+      simp only [← show k < _ + 1 ↔ _ from Nat.lt_succ (n := xs.size - 1), this, Nat.zero_le,
         true_and, Nat.not_lt] at h
       rw [List.getElem?_eq_none_iff.2 ‹_›, List.getElem?_eq_none_iff.2 (xs.toList.length_reverse ▸ ‹_›)]
 
@@ -2690,6 +2800,9 @@ theorem flatten_reverse {xss : Array (Array α)} :
   rw [← toList_inj]
   simp
 
+@[deprecated reverse_replicate (since := "2025-03-18")]
+abbrev reverse_mkArray := @reverse_replicate
+
 /-! ### extract -/
 
 theorem extract_loop_zero {xs ys : Array α} {start : Nat} : extract.loop xs 0 start ys = ys := by
@@ -2709,8 +2822,8 @@ theorem extract_loop_eq_aux {xs ys : Array α} {size start : Nat} :
   | zero => rw [extract_loop_zero, extract_loop_zero, append_empty]
   | succ size ih =>
     if h : start < xs.size then
-      rw [extract_loop_succ (h := h), ih, push_eq_append]
-      rw [extract_loop_succ (h := h), ih (ys := #[].push _), push_eq_append, empty_append]
+      rw [extract_loop_succ (h := h), ih, push_eq_append_singleton]
+      rw [extract_loop_succ (h := h), ih (ys := #[].push _), push_eq_append_singleton, empty_append]
       rw [append_assoc]
     else
       rw [extract_loop_of_ge (h := Nat.le_of_not_lt h)]
@@ -3247,6 +3360,14 @@ rather than `(arr.push a).size` as the argument.
     l.foldl (fun xs x => xs.push x) xs = xs ++ l.toArray := by
   simpa using List.foldl_push_eq_append (f := id)
 
+@[deprecated _root_.List.foldl_push_eq_append' (since := "2025-05-18")]
+theorem _root_.List.foldl_push {l : List α} {as : Array α} : l.foldl Array.push as = as ++ l.toArray := by
+  induction l generalizing as <;> simp [*]
+
+@[deprecated _root_.List.foldr_push_eq_append' (since := "2025-05-18")]
+theorem _root_.List.foldr_push {l : List α} {as : Array α} : l.foldr (fun a bs => push bs a) as = as ++ l.reverse.toArray := by
+  rw [List.foldr_eq_foldl_reverse, List.foldl_push_eq_append']
+
 -- TODO: a multi-pattern is being selected there because E-matching does not go inside lambdas.
 @[simp, grind! ←] theorem foldr_append_eq_append {xs : Array α} {f : α → Array β} {ys : Array β} :
     xs.foldr (f · ++ ·) ys = (xs.map f).flatten ++ ys := by
@@ -3319,16 +3440,6 @@ theorem foldr_filterMap {f : α → Option β} {g : β → γ → γ} {xs : Arra
     (xs.filterMap f).foldr g init = xs.foldr (fun x y => match f x with | some b => g b y | none => y) init := by
   simp [foldr_filterMap']
 
-theorem foldl_flatMap {f : α → Array β} {g : γ → β → γ} {xs : Array α} {init : γ} :
-    (xs.flatMap f).foldl g init = xs.foldl (fun acc x => (f x).foldl g acc) init := by
-  rcases xs with ⟨l⟩
-  simp [List.foldl_flatMap]
-
-theorem foldr_flatMap {f : α → Array β} {g : β → γ → γ} {xs : Array α} {init : γ} :
-    (xs.flatMap f).foldr g init = xs.foldr (fun x acc => (f x).foldr g acc) init := by
-  rcases xs with ⟨l⟩
-  simp [List.foldr_flatMap]
-
 theorem foldl_map_hom' {g : α → β} {f : α → α → α} {f' : β → β → β} {a : α} {xs : Array α}
     {stop : Nat} (h : ∀ x y, f' (g x) (g y) = g (f x y)) (w : stop = xs.size) :
     (xs.map g).foldl f' (g a) 0 stop = g (xs.foldl f a) := by
@@ -3546,6 +3657,11 @@ theorem mem_of_back? {xs : Array α} {a : α} (h : xs.back? = some a) : a ∈ xs
   rcases ys with ⟨ys⟩
   simp only [List.append_toArray, List.back_toArray, List.getLast_append, List.isEmpty_iff,
     List.isEmpty_toArray]
+  split
+  · rw [dif_pos]
+    simpa only [List.isEmpty_toArray]
+  · rw [dif_neg]
+    simpa only [List.isEmpty_toArray]
 
 theorem back_append_right {xs ys : Array α} (h : 0 < ys.size) :
     (xs ++ ys).back (by simp; omega) = ys.back h := by
@@ -3596,9 +3712,15 @@ theorem back?_replicate {a : α} {n : Nat} :
   rw [replicate_eq_toArray_replicate]
   simp only [List.back?_toArray, List.getLast?_replicate]
 
+@[deprecated back?_replicate (since := "2025-03-18")]
+abbrev back?_mkArray := @back?_replicate
+
 @[simp] theorem back_replicate {xs : Array α} (w : 0 < n) : (replicate n xs).back (by simpa using w) = xs := by
   simp [back_eq_getElem]
 
+@[deprecated back_replicate (since := "2025-03-18")]
+abbrev back_mkArray := @back_replicate
+
 /-! ## Additional operations -/
 
 /-! ### leftpad -/
@@ -3616,6 +3738,9 @@ theorem size_rightpad {n : Nat} {a : α} {xs : Array α} :
 
 theorem elem_push_self [BEq α] [LawfulBEq α] {xs : Array α} {a : α} : (xs.push a).elem a = true := by simp
 
+@[deprecated elem_push_self (since := "2025-04-04")]
+abbrev elem_cons_self := @elem_push_self
+
 theorem contains_eq_any_beq [BEq α] {xs : Array α} {a : α} : xs.contains a = xs.any (a == ·) := by
   rcases xs with ⟨xs⟩
   simp [List.contains_eq_any_beq]
@@ -3629,6 +3754,11 @@ theorem contains_iff_exists_mem_beq [BEq α] {xs : Array α} {a : α} :
 -- With `LawfulBEq α`, it would be better to use `contains_iff_mem` directly.
 grind_pattern contains_iff_exists_mem_beq => xs.contains a
 
+@[grind =]
+theorem contains_iff_mem [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
+    xs.contains a ↔ a ∈ xs := by
+  simp
+
 @[simp, grind =]
 theorem contains_toList [BEq α] {xs : Array α} {x : α} :
     xs.toList.contains x = xs.contains x := by
@@ -3688,6 +3818,9 @@ theorem pop_append {xs ys : Array α} :
 @[simp, grind =] theorem pop_replicate {n : Nat} {a : α} : (replicate n a).pop = replicate (n - 1) a := by
   ext <;> simp
 
+@[deprecated pop_replicate (since := "2025-03-18")]
+abbrev pop_mkArray := @pop_replicate
+
 /-! ## Logic -/
 
 /-! ### any / all -/
@@ -3917,10 +4050,16 @@ theorem all_filterMap {xs : Array α} {f : α → Option β} {p : β → Bool} :
     (replicate n a).any f = if n = 0 then false else f a := by
   induction n <;> simp_all [replicate_succ']
 
+@[deprecated any_replicate (since := "2025-03-18")]
+abbrev any_mkArray := @any_replicate
+
 @[simp] theorem all_replicate {n : Nat} {a : α} :
     (replicate n a).all f = if n = 0 then true else f a := by
   induction n <;> simp_all +contextual [replicate_succ']
 
+@[deprecated all_replicate (since := "2025-03-18")]
+abbrev all_mkArray := @all_replicate
+
 /-! ### modify -/
 
 @[simp, grind =] theorem size_modify {xs : Array α} {i : Nat} {f : α → α} : (xs.modify i f).size = xs.size := by
@@ -3957,29 +4096,28 @@ theorem getElem_modify_of_ne {xs : Array α} {i : Nat} (h : i ≠ j)
 
 /-! ### swap -/
 
-@[grind =]
-theorem getElem_swap {xs : Array α} {i j : Nat} (hi hj) {k : Nat} (hk : k < (xs.swap i j hi hj).size) :
-    (xs.swap i j hi hj)[k] = if k = i then xs[j] else if k = j then xs[i] else xs[k]'(by simp_all) := by
-  simp only [swap_def, getElem_set, eq_comm (a := k)]
-  split <;> split <;> simp_all
-
 @[simp] theorem getElem_swap_right {xs : Array α} {i j : Nat} {hi hj} :
     (xs.swap i j hi hj)[j]'(by simpa using hj) = xs[i] := by
-  simp +contextual [getElem_swap]
+  simp [swap_def]
 
 @[simp] theorem getElem_swap_left {xs : Array α} {i j : Nat} {hi hj} :
     (xs.swap i j hi hj)[i]'(by simpa using hi) = xs[j] := by
-  simp [getElem_swap]
+  simp +contextual [swap_def, getElem_set]
 
-@[simp] theorem getElem_swap_of_ne {xs : Array α} {i j : Nat} {hi hj}
-    {h : k < (xs.swap i j hi hj).size} (hi' : k ≠ i) (hj' : k ≠ j) :
-    (xs.swap i j hi hj)[k] = xs[k]'(by simp_all) := by
-  simp [getElem_swap, hi', hj']
+@[simp] theorem getElem_swap_of_ne {xs : Array α} {i j : Nat} {hi hj} (hp : k < xs.size)
+    (hi' : k ≠ i) (hj' : k ≠ j) : (xs.swap i j hi hj)[k]'(xs.size_swap .. |>.symm ▸ hp) = xs[k] := by
+  simp [swap_def, getElem_set, hi'.symm, hj'.symm]
 
-@[deprecated getElem_swap (since := "2025-10-10")]
 theorem getElem_swap' {xs : Array α} {i j : Nat} {hi hj} {k : Nat} (hk : k < xs.size) :
-    (xs.swap i j hi hj)[k]'(by simp_all) = if k = i then xs[j] else if k = j then xs[i] else xs[k] :=
-  getElem_swap _ _ _
+    (xs.swap i j hi hj)[k]'(by simp_all) = if k = i then xs[j] else if k = j then xs[i] else xs[k] := by
+  split
+  · simp_all only [getElem_swap_left]
+  · split <;> simp_all
+
+@[grind =]
+theorem getElem_swap {xs : Array α} {i j : Nat} (hi hj) {k : Nat} (hk : k < (xs.swap i j hi hj).size) :
+    (xs.swap i j hi hj)[k] = if k = i then xs[j] else if k = j then xs[i] else xs[k]'(by simp_all) := by
+  apply getElem_swap'
 
 @[simp] theorem swap_swap {xs : Array α} {i j : Nat} (hi hj) :
     (xs.swap i j hi hj).swap i j ((xs.size_swap ..).symm ▸ hi) ((xs.size_swap ..).symm ▸ hj) = xs := by
@@ -4000,66 +4138,8 @@ theorem swap_comm {xs : Array α} {i j : Nat} (hi hj) : xs.swap i j hi hj = xs.s
     · split <;> simp_all
     · split <;> simp_all
 
-/-! ### swapIfInBounds -/
-
-@[grind =] theorem swapIfInBounds_def {xs : Array α} {i j : Nat} :
-    xs.swapIfInBounds i j = if h₁ : i < xs.size then
-  if h₂ : j < xs.size then swap xs i j else xs else xs := rfl
-
 @[simp, grind =] theorem size_swapIfInBounds {xs : Array α} {i j : Nat} :
-    (xs.swapIfInBounds i j).size = xs.size := by
-  unfold swapIfInBounds; split <;> (try split) <;> simp [size_swap]
-
-@[grind =] theorem getElem_swapIfInBounds {xs : Array α} {i j k : Nat}
-    (hk : k < (xs.swapIfInBounds i j).size) :
-    (xs.swapIfInBounds i j)[k] =
-    if h₁ : k = i ∧ j < xs.size then xs[j]'h₁.2 else if h₂ : k = j ∧ i < xs.size then xs[i]'h₂.2
-    else xs[k]'(by simp_all) := by
-  rw [size_swapIfInBounds] at hk
-  unfold swapIfInBounds
-  split <;> rename_i hi
-  · split <;> rename_i hj
-    · simp only [hi, hj, and_true]
-      exact getElem_swap _ _ _
-    · simp only [hi, hj, and_true, and_false, dite_false]
-      split <;> simp_all
-  · simp only [hi, and_false, dite_false]
-    split <;> simp_all
-
-@[simp]
-theorem getElem_swapIfInBounds_of_size_le_left {xs : Array α} {i j k : Nat} (hi : xs.size ≤ i)
-    (hk : k < (xs.swapIfInBounds i j).size) :
-    (xs.swapIfInBounds i j)[k] = xs[k]'(Nat.lt_of_lt_of_eq hk size_swapIfInBounds) := by
-  have h₁ : k ≠ i := Nat.ne_of_lt <| Nat.lt_of_lt_of_le hk <|
-    Nat.le_trans (Nat.le_of_eq (size_swapIfInBounds)) hi
-  have h₂ : ¬ (i < xs.size) := Nat.not_lt_of_le hi
-  simp [getElem_swapIfInBounds, h₁, h₂]
-
-@[simp]
-theorem getElem_swapIfInBounds_of_size_le_right {xs : Array α} {i j k : Nat} (hj : xs.size ≤ j)
-    (hk : k < (xs.swapIfInBounds i j).size) :
-    (xs.swapIfInBounds i j)[k] = xs[k]'(Nat.lt_of_lt_of_eq hk size_swapIfInBounds) := by
-  have h₁ : ¬ (j < xs.size) := Nat.not_lt_of_le hj
-  have h₂ : k ≠ j := Nat.ne_of_lt <| Nat.lt_of_lt_of_le hk <|
-    Nat.le_trans (Nat.le_of_eq (size_swapIfInBounds)) hj
-  simp [getElem_swapIfInBounds, h₁, h₂]
-
-@[simp]
-theorem getElem_swapIfInBounds_left {xs : Array α} {i j : Nat} (hj : j < xs.size)
-    (hi : i < (xs.swapIfInBounds i j).size) : (xs.swapIfInBounds i j)[i] = xs[j] := by
-  simp [getElem_swapIfInBounds, hj]
-
-@[simp]
-theorem getElem_swapIfInBounds_right {xs : Array α} {i j : Nat} (hi : i < xs.size)
-    (hj : j < (xs.swapIfInBounds i j).size) :
-    (xs.swapIfInBounds i j)[j] = xs[i] := by
-  simp +contextual [getElem_swapIfInBounds, hi]
-
-@[simp]
-theorem getElem_swapIfInBounds_of_ne_of_ne {xs : Array α} {i j k : Nat} (hi : k ≠ i) (hj : k ≠ j)
-    (hk : k < (xs.swapIfInBounds i j).size) :
-    (xs.swapIfInBounds i j)[k] = xs[k]'(Nat.lt_of_lt_of_eq hk size_swapIfInBounds) := by
-  simp [getElem_swapIfInBounds, hi, hj]
+    (xs.swapIfInBounds i j).size = xs.size := by unfold swapIfInBounds; split <;> (try split) <;> simp [size_swap]
 
 /-! ### swapAt -/
 
@@ -4154,11 +4234,17 @@ theorem replace_extract {xs : Array α} {i : Nat} :
     (replicate n a).replace a b = #[b] ++ replicate (n - 1) a := by
   cases n <;> simp_all [replicate_succ', replace_append]
 
+@[deprecated replace_replicate_self (since := "2025-03-18")]
+abbrev replace_mkArray_self := @replace_replicate_self
+
 @[simp] theorem replace_replicate_ne {a b c : α} (h : !b == a) :
     (replicate n a).replace b c = replicate n a := by
   rw [replace_of_not_mem]
   simp_all
 
+@[deprecated replace_replicate_ne (since := "2025-03-18")]
+abbrev replace_mkArray_ne := @replace_replicate_ne
+
 end replace
 
 /-! ### toListRev -/
@@ -4321,9 +4407,13 @@ theorem size_uset {xs : Array α} {v : α} {i : USize} (h : i.toNat < xs.size) :
 theorem getElem!_eq_getD [Inhabited α] {xs : Array α} {i} : xs[i]! = xs.getD i default := by
   rfl
 
-theorem getElem_eq_getD {xs : Array α} {i} {h : i < xs.size} (fallback : α) :
-    xs[i]'h = xs.getD i fallback := by
-  rw [getD_eq_getD_getElem?, getElem_eq_getElem?_get, Option.get_eq_getD]
+/-! # mem -/
+
+@[deprecated mem_toList_iff (since := "2025-05-26")]
+theorem mem_toList {a : α} {xs : Array α} : a ∈ xs.toList ↔ a ∈ xs := mem_def.symm
+
+@[deprecated not_mem_empty (since := "2025-03-25")]
+theorem not_mem_nil (a : α) : ¬ a ∈ #[] := nofun
 
 /-! # get lemmas -/
 
@@ -4336,7 +4426,6 @@ theorem getElem_fin_eq_getElem_toList {xs : Array α} {i : Fin xs.size} : xs[i]
 @[simp] theorem ugetElem_eq_getElem {xs : Array α} {i : USize} (h : i.toNat < xs.size) :
   xs[i] = xs[i.toNat] := rfl
 
-@[deprecated getElem?_eq_none (since := "2025-10-26")]
 theorem getElem?_size_le {xs : Array α} {i : Nat} (h : xs.size ≤ i) : xs[i]? = none := by
   simp [getElem?_neg, h]
 
@@ -4356,7 +4445,6 @@ theorem getElem?_push_lt {xs : Array α} {x : α} {i : Nat} (h : i < xs.size) :
     (xs.push x)[i]? = some xs[i] := by
   rw [getElem?_pos (xs.push x) i (size_push _ ▸ Nat.lt_succ_of_lt h), getElem_push_lt]
 
-@[deprecated getElem?_push_size (since := "2025-10-26")]
 theorem getElem?_push_eq {xs : Array α} {x : α} : (xs.push x)[xs.size]? = some x := by
   rw [getElem?_pos (xs.push x) xs.size (size_push _ ▸ Nat.lt_succ_self xs.size), getElem_push_eq]
 
@@ -4375,6 +4463,12 @@ theorem getElem?_push_eq {xs : Array α} {x : α} : (xs.push x)[xs.size]? = some
   cases xs
   simp
 
+/-! ### contains -/
+
+@[deprecated contains_iff (since := "2025-04-07")]
+abbrev contains_def [DecidableEq α] {a : α} {xs : Array α} : xs.contains a ↔ a ∈ xs :=
+  contains_iff
+
 /-! ### isPrefixOf -/
 
 @[simp, grind =] theorem isPrefixOf_toList [BEq α] {xs ys : Array α} :
@@ -4488,8 +4582,7 @@ theorem uset_toArray {l : List α} {i : USize} {a : α} {h : i.toNat < l.toArray
   apply ext'
   simp
 
-@[deprecated Array.flatten_map_toArray_toArray (since := "2025-10-26")]
-theorem flatten_toArray {L : List (List α)} :
+@[simp, grind =] theorem flatten_toArray {L : List (List α)} :
     (L.toArray.map List.toArray).flatten = L.flatten.toArray := by
   apply ext'
   simp

src/Init/Data/Array/Lex/Lemmas.lean

@@ -34,18 +34,7 @@ grind_pattern _root_.List.le_toArray => l₁.toArray ≤ l₂.toArray
 grind_pattern lt_toList => xs.toList < ys.toList
 grind_pattern le_toList => xs.toList ≤ ys.toList
 
-@[simp]
-protected theorem not_lt [LT α] {xs ys : Array α} : ¬ xs < ys ↔ ys ≤ xs := Iff.rfl
-
-@[deprecated Array.not_lt (since := "2025-10-26")]
 protected theorem not_lt_iff_ge [LT α] {xs ys : Array α} : ¬ xs < ys ↔ ys ≤ xs := Iff.rfl
-
-@[simp]
-protected theorem not_le [LT α] {xs ys : Array α} :
-    ¬ xs ≤ ys ↔ ys < xs :=
-  Classical.not_not
-
-@[deprecated Array.not_le (since := "2025-10-26")]
 protected theorem not_le_iff_gt [LT α] {xs ys : Array α} :
     ¬ xs ≤ ys ↔ ys < xs :=
   Classical.not_not
@@ -73,11 +62,19 @@ private theorem cons_lex_cons [BEq α] {lt : α → α → Bool} {a b : α} {xs
        (lt a b || a == b && xs.lex ys lt) := by
   simp only [lex, size_append, List.size_toArray, List.length_cons, List.length_nil, Nat.zero_add,
     Nat.add_min_add_left, Nat.add_lt_add_iff_left, Std.Rco.forIn'_eq_forIn'_toList]
-  rw [cons_lex_cons.forIn'_congr_aux (Nat.toList_rco_eq_cons (by omega)) rfl (fun _ _ _ => rfl)]
-  simp only [bind_pure_comp, map_pure, Nat.toList_rco_succ_succ, Nat.add_comm 1]
-  cases h : lt a b
-  · cases h' : a == b <;> simp [bne, *]
-  · simp [*]
+  conv =>
+    lhs; congr; congr
+    rw [cons_lex_cons.forIn'_congr_aux Std.Rco.toList_eq_if rfl (fun _ _ _ => rfl)]
+    simp only [bind_pure_comp, map_pure]
+    rw [cons_lex_cons.forIn'_congr_aux (if_pos (by omega)) rfl (fun _ _ _ => rfl)]
+  simp only [Std.toList_Roo_eq_toList_Rco_of_isSome_succ? (lo := 0) (h := rfl),
+    Std.PRange.UpwardEnumerable.succ?, Nat.add_comm 1, Std.PRange.Nat.toList_Rco_succ_succ,
+    Option.get_some, List.forIn'_cons, List.size_toArray, List.length_cons, List.length_nil,
+    Nat.lt_add_one, getElem_append_left, List.getElem_toArray, List.getElem_cons_zero]
+  cases lt a b
+  · rw [bne]
+    cases a == b <;> simp
+  · simp
 
 @[simp, grind =] theorem _root_.List.lex_toArray [BEq α] {lt : α → α → Bool} {l₁ l₂ : List α} :
     l₁.toArray.lex l₂.toArray lt = l₁.lex l₂ lt := by
@@ -143,7 +140,7 @@ protected theorem lt_of_le_of_lt [LE α] [LT α] [LawfulOrderLT α] [IsLinearOrd
 @[deprecated Array.lt_of_le_of_lt (since := "2025-08-01")]
 protected theorem lt_of_le_of_lt' [LT α]
     [i₁ : Std.Asymm (· < · : α → α → Prop)]
-    [i₂ : Std.Trichotomous (· < · : α → α → Prop)]
+    [i₂ : Std.Antisymm (¬ · < · : α → α → Prop)]
     [i₃ : Trans (¬ · < · : α → α → Prop) (¬ · < ·) (¬ · < ·)]
     {xs ys zs : Array α} (h₁ : xs ≤ ys) (h₂ : ys < zs) : xs < zs :=
   letI := LE.ofLT α
@@ -157,7 +154,7 @@ protected theorem le_trans [LE α] [LT α] [LawfulOrderLT α] [IsLinearOrder α]
 @[deprecated Array.le_trans (since := "2025-08-01")]
 protected theorem le_trans' [LT α]
     [i₁ : Std.Asymm (· < · : α → α → Prop)]
-    [i₂ : Std.Trichotomous (· < · : α → α → Prop)]
+    [i₂ : Std.Antisymm (¬ · < · : α → α → Prop)]
     [i₃ : Trans (¬ · < · : α → α → Prop) (¬ · < ·) (¬ · < ·)]
     {xs ys zs : Array α} (h₁ : xs ≤ ys) (h₂ : ys ≤ zs) : xs ≤ zs :=
   letI := LE.ofLT α
@@ -181,6 +178,12 @@ protected theorem le_total [LT α]
     [i : Std.Asymm (· < · : α → α → Prop)] (xs ys : Array α) : xs ≤ ys ∨ ys ≤ xs :=
   List.le_total xs.toList ys.toList
 
+@[simp] protected theorem not_lt [LT α]
+    {xs ys : Array α} : ¬ xs < ys ↔ ys ≤ xs := Iff.rfl
+
+@[simp] protected theorem not_le [LT α]
+    {xs ys : Array α} : ¬ ys ≤ xs ↔ xs < ys := Classical.not_not
+
 protected theorem le_of_lt [LT α]
     [i : Std.Asymm (· < · : α → α → Prop)]
     {xs ys : Array α} (h : xs < ys) : xs ≤ ys :=
@@ -188,7 +191,7 @@ protected theorem le_of_lt [LT α]
 
 protected theorem le_iff_lt_or_eq [LT α]
     [Std.Irrefl (· < · : α → α → Prop)]
-    [Std.Trichotomous (· < · : α → α → Prop)]
+    [Std.Antisymm (¬ · < · : α → α → Prop)]
     [Std.Asymm (· < · : α → α → Prop)]
     {xs ys : Array α} : xs ≤ ys ↔ xs < ys ∨ xs = ys := by
   simpa using List.le_iff_lt_or_eq (l₁ := xs.toList) (l₂ := ys.toList)
@@ -277,7 +280,7 @@ protected theorem lt_iff_exists [LT α] {xs ys : Array α} :
 
 protected theorem le_iff_exists [LT α]
     [Std.Asymm (· < · : α → α → Prop)]
-    [Std.Trichotomous (· < · : α → α → Prop)] {xs ys : Array α} :
+    [Std.Antisymm (¬ · < · : α → α → Prop)] {xs ys : Array α} :
     xs ≤ ys ↔
       (xs = ys.take xs.size) ∨
         (∃ (i : Nat) (h₁ : i < xs.size) (h₂ : i < ys.size),
@@ -296,7 +299,7 @@ theorem append_left_lt [LT α] {xs ys zs : Array α} (h : ys < zs) :
 
 theorem append_left_le [LT α]
     [Std.Asymm (· < · : α → α → Prop)]
-    [Std.Trichotomous (· < · : α → α → Prop)]
+    [Std.Antisymm (¬ · < · : α → α → Prop)]
     {xs ys zs : Array α} (h : ys ≤ zs) :
     xs ++ ys ≤ xs ++ zs := by
   cases xs
@@ -319,9 +322,9 @@ protected theorem map_lt [LT α] [LT β]
 
 protected theorem map_le [LT α] [LT β]
     [Std.Asymm (· < · : α → α → Prop)]
-    [Std.Trichotomous (· < · : α → α → Prop)]
+    [Std.Antisymm (¬ · < · : α → α → Prop)]
     [Std.Asymm (· < · : β → β → Prop)]
-    [Std.Trichotomous (· < · : β → β → Prop)]
+    [Std.Antisymm (¬ · < · : β → β → Prop)]
     {xs ys : Array α} {f : α → β} (w : ∀ x y, x < y → f x < f y) (h : xs ≤ ys) :
     map f xs ≤ map f ys := by
   cases xs

src/Init/Data/Array/MapIdx.lean

@@ -296,6 +296,9 @@ theorem mapFinIdx_eq_replicate_iff {xs : Array α} {f : (i : Nat) → α → (h
   rw [← toList_inj]
   simp [List.mapFinIdx_eq_replicate_iff]
 
+@[deprecated mapFinIdx_eq_replicate_iff (since := "2025-03-18")]
+abbrev mapFinIdx_eq_mkArray_iff := @mapFinIdx_eq_replicate_iff
+
 @[simp, grind =] theorem mapFinIdx_reverse {xs : Array α} {f : (i : Nat) → α → (h : i < xs.reverse.size) → β} :
     xs.reverse.mapFinIdx f = (xs.mapFinIdx (fun i a h => f (xs.size - 1 - i) a (by simp; omega))).reverse := by
   rcases xs with ⟨l⟩
@@ -435,6 +438,9 @@ theorem mapIdx_eq_replicate_iff {xs : Array α} {f : Nat → α → β} {b : β}
   rw [← toList_inj]
   simp [List.mapIdx_eq_replicate_iff]
 
+@[deprecated mapIdx_eq_replicate_iff (since := "2025-03-18")]
+abbrev mapIdx_eq_mkArray_iff := @mapIdx_eq_replicate_iff
+
 @[simp, grind =] theorem mapIdx_reverse {xs : Array α} {f : Nat → α → β} :
     xs.reverse.mapIdx f = (mapIdx (fun i => f (xs.size - 1 - i)) xs).reverse := by
   rcases xs with ⟨xs⟩

src/Init/Data/Array/Monadic.lean

@@ -39,6 +39,10 @@ theorem map_toList_inj [Monad m] [LawfulMonad m]
 @[simp, grind =] theorem idRun_mapM {xs : Array α} {f : α → Id β} : (xs.mapM f).run = xs.map (f · |>.run) :=
   mapM_pure
 
+@[deprecated idRun_mapM (since := "2025-05-21")]
+theorem mapM_id {xs : Array α} {f : α → Id β} : xs.mapM f = xs.map f :=
+  mapM_pure
+
 @[simp, grind =] theorem mapM_map [Monad m] [LawfulMonad m] {f : α → β} {g : β → m γ} {xs : Array α} :
     (xs.map f).mapM g = xs.mapM (g ∘ f) := by
   rcases xs with ⟨xs⟩
@@ -197,6 +201,13 @@ theorem idRun_forIn'_yield_eq_foldl
       xs.attach.foldl (fun b ⟨a, h⟩ => f a h b |>.run) init := by
   simp
 
+@[deprecated idRun_forIn'_yield_eq_foldl (since := "2025-05-21")]
+theorem forIn'_yield_eq_foldl
+    {xs : Array α} (f : (a : α) → a ∈ xs → β → β) (init : β) :
+    forIn' (m := Id) xs init (fun a m b => .yield (f a m b)) =
+      xs.attach.foldl (fun b ⟨a, h⟩ => f a h b) init :=
+  forIn'_pure_yield_eq_foldl _ _
+
 @[simp, grind =] theorem forIn'_map [Monad m] [LawfulMonad m]
     {xs : Array α} (g : α → β) (f : (b : β) → b ∈ xs.map g → γ → m (ForInStep γ)) :
     forIn' (xs.map g) init f = forIn' xs init fun a h y => f (g a) (mem_map_of_mem h) y := by
@@ -238,6 +249,13 @@ theorem idRun_forIn_yield_eq_foldl
       xs.foldl (fun b a => f a b |>.run) init := by
   simp
 
+@[deprecated idRun_forIn_yield_eq_foldl (since := "2025-05-21")]
+theorem forIn_yield_eq_foldl
+    {xs : Array α} (f : α → β → β) (init : β) :
+    forIn (m := Id) xs init (fun a b => .yield (f a b)) =
+      xs.foldl (fun b a => f a b) init :=
+  forIn_pure_yield_eq_foldl _ _
+
 @[simp, grind =] theorem forIn_map [Monad m] [LawfulMonad m]
     {xs : Array α} {g : α → β} {f : β → γ → m (ForInStep γ)} :
     forIn (xs.map g) init f = forIn xs init fun a y => f (g a) y := by

src/Init/Data/Array/Perm.lean

@@ -84,6 +84,9 @@ theorem Perm.size_eq {xs ys : Array α} (p : xs ~ ys) : xs.size = ys.size := by
   simp only [perm_iff_toList_perm] at p
   simpa using p.length_eq
 
+@[deprecated Perm.size_eq (since := "2025-04-17")]
+abbrev Perm.length_eq := @Perm.size_eq
+
 theorem Perm.mem_iff {a : α} {xs ys : Array α} (p : xs ~ ys) : a ∈ xs ↔ a ∈ ys := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
@@ -104,7 +107,7 @@ grind_pattern Perm.append => xs ~ ys, as ~ bs, ys ++ bs
 
 theorem Perm.push (x : α) {xs ys : Array α} (p : xs ~ ys) :
     xs.push x ~ ys.push x := by
-  rw [push_eq_append]
+  rw [push_eq_append_singleton]
   exact p.append .rfl
 
 grind_pattern Perm.push => xs ~ ys, xs.push x

src/Init/Data/Array/Subarray.lean

@@ -280,7 +280,7 @@ Checks whether any of the elements in a subarray satisfy a Boolean predicate.
 The elements are tested starting at the lowest index and moving up. The search terminates as soon as
 an element that satisfies the predicate is found.
 -/
-@[inline, suggest_for Subarray.some]
+@[inline]
 def any {α : Type u} (p : α → Bool) (as : Subarray α) : Bool :=
   Id.run <| as.anyM (pure <| p ·)
 
@@ -290,7 +290,7 @@ Checks whether all of the elements in a subarray satisfy a Boolean predicate.
 The elements are tested starting at the lowest index and moving up. The search terminates as soon as
 an element that does not satisfy the predicate is found.
 -/
-@[inline, suggest_for Subarray.every]
+@[inline]
 def all {α : Type u} (p : α → Bool) (as : Subarray α) : Bool :=
   Id.run <| as.allM (pure <| p ·)
 

src/Init/Data/Array/Zip.lean

@@ -166,6 +166,9 @@ theorem zipWith_eq_append_iff {f : α → β → γ} {as : Array α} {bs : Array
     zipWith f (replicate m a) (replicate n b) = replicate (min m n) (f a b) := by
   simp [← List.toArray_replicate]
 
+@[deprecated zipWith_replicate (since := "2025-03-18")]
+abbrev zipWith_mkArray := @zipWith_replicate
+
 theorem map_uncurry_zip_eq_zipWith {f : α → β → γ} {as : Array α} {bs : Array β} :
     map (Function.uncurry f) (as.zip bs) = zipWith f as bs := by
   cases as
@@ -291,6 +294,9 @@ theorem zip_eq_append_iff {as : Array α} {bs : Array β} :
     zip (replicate m a) (replicate n b) = replicate (min m n) (a, b) := by
   simp [← List.toArray_replicate]
 
+@[deprecated zip_replicate (since := "2025-03-18")]
+abbrev zip_mkArray := @zip_replicate
+
 theorem zip_eq_zip_take_min {as : Array α} {bs : Array β} :
     zip as bs = zip (as.take (min as.size bs.size)) (bs.take (min as.size bs.size)) := by
   cases as
@@ -342,6 +348,9 @@ theorem map_zipWithAll {δ : Type _} {f : α → β} {g : Option γ → Option
     zipWithAll f (replicate n a) (replicate n b) = replicate n (f (some a) (some b)) := by
   simp [← List.toArray_replicate]
 
+@[deprecated zipWithAll_replicate (since := "2025-03-18")]
+abbrev zipWithAll_mkArray := @zipWithAll_replicate
+
 /-! ### zipWithM -/
 
 @[simp, grind =]
@@ -353,6 +362,14 @@ theorem zipWithM_eq_mapM_id_zipWith {m : Type v → Type w} [Monad m] [LawfulMon
 
 /-! ### unzip -/
 
+@[deprecated fst_unzip (since := "2025-05-26")]
+theorem unzip_fst : (unzip l).fst = l.map Prod.fst := by
+  simp
+
+@[deprecated snd_unzip (since := "2025-05-26")]
+theorem unzip_snd : (unzip l).snd = l.map Prod.snd := by
+  simp
+
 @[grind =]
 theorem unzip_eq_map {xs : Array (α × β)} : unzip xs = (xs.map Prod.fst, xs.map Prod.snd) := by
   cases xs
@@ -391,4 +408,7 @@ theorem zip_of_prod {as : Array α} {bs : Array β} {xs : Array (α × β)} (hl
     unzip (replicate n (a, b)) = (replicate n a, replicate n b) := by
   ext1 <;> simp
 
+@[deprecated unzip_replicate (since := "2025-03-18")]
+abbrev unzip_mkArray := @unzip_replicate
+
 end Array

src/Init/Data/Basic.lean

@@ -0,0 +1,10 @@
+/-
+Copyright (c) 2016 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Leonardo de Moura
+-/
+module
+
+prelude
+public import Init.Data.UInt
+public import Init.Data.String.Extra

src/Init/Data/BitVec/Basic.lean

@@ -77,6 +77,9 @@ Returns the `i`th least significant bit.
 -/
 @[inline, expose] def getLsb (x : BitVec w) (i : Fin w) : Bool := x.toNat.testBit i
 
+@[deprecated getLsb (since := "2025-06-17"), inherit_doc getLsb]
+abbrev getLsb' := @getLsb
+
 /-- Returns the `i`th least significant bit, or `none` if `i ≥ w`. -/
 @[inline, expose] def getLsb? (x : BitVec w) (i : Nat) : Option Bool :=
   if h : i < w then some (getLsb x ⟨i, h⟩) else none
@@ -86,6 +89,9 @@ Returns the `i`th most significant bit.
 -/
 @[inline] def getMsb (x : BitVec w) (i : Fin w) : Bool := x.getLsb ⟨w-1-i, by omega⟩
 
+@[deprecated getMsb (since := "2025-06-17"), inherit_doc getMsb]
+abbrev getMsb' := @getMsb
+
 /-- Returns the `i`th most significant bit or `none` if `i ≥ w`. -/
 @[inline] def getMsb? (x : BitVec w) (i : Nat) : Option Bool :=
   if h : i < w then some (getMsb x ⟨i, h⟩) else none
@@ -197,8 +203,8 @@ If `n` is `0`, then one digit is returned. Otherwise, `⌊(n + 3) / 4⌋` digits
 -- `Internal` string functions by moving this definition out to a separate file that can live
 -- downstream of `Init.Data.String.Basic`.
 protected def toHex {n : Nat} (x : BitVec n) : String :=
-  let s := String.ofList (Nat.toDigits 16 x.toNat)
-  let t := String.ofList (List.replicate ((n+3) / 4 - String.Internal.length s) '0')
+  let s := (Nat.toDigits 16 x.toNat).asString
+  let t := (List.replicate ((n+3) / 4 - String.Internal.length s) '0').asString
   String.Internal.append t s
 
 /-- `BitVec` representation. -/
@@ -290,7 +296,7 @@ Lean convention that division by zero returns zero.
 
 Examples:
 * `(7#4).sdiv 2 = 3#4`
-* `(-8#4).sdiv 2 = -4#4`
+* `(-9#4).sdiv 2 = -4#4`
 * `(5#4).sdiv -2 = -2#4`
 * `(-7#4).sdiv (-2) = 3#4`
 -/
@@ -864,17 +870,4 @@ def clz (x : BitVec w) : BitVec w := clzAuxRec x (w - 1)
 /-- Count the number of trailing zeros. -/
 def ctz (x : BitVec w) : BitVec w := (x.reverse).clz
 
-/-- Count the number of bits with value `1` downward from the `pos`-th bit to the
-  `0`-th bit of `x`, storing the result in `acc`. -/
-def cpopNatRec (x : BitVec w) (pos acc : Nat) : Nat :=
-  match pos with
-  | 0 => acc
-  | n + 1 => x.cpopNatRec n (acc + (x.getLsbD n).toNat)
-
-/-- Population count operation, to count the number of bits with value `1` in `x`.
-  Also known as `popcount`, `popcnt`.
--/
-@[suggest_for BitVec.popcount BitVec.popcnt]
-def cpop (x : BitVec w) : BitVec w := BitVec.ofNat w (cpopNatRec x w 0)
-
 end BitVec

src/Init/Data/BitVec/Bitblast.lean

@@ -635,11 +635,12 @@ theorem mulRec_eq_mul_signExtend_setWidth (x y : BitVec w) (s : Nat) :
     simp only [mulRec_zero_eq, ofNat_eq_ofNat, Nat.reduceAdd]
     by_cases y.getLsbD 0
     case pos hy =>
-      simp only [hy, ↓reduceIte, setWidth_one, ofBool_true, ofNat_eq_ofNat]
+      simp only [hy, ↓reduceIte, setWidth_one_eq_ofBool_getLsb_zero,
+        ofBool_true, ofNat_eq_ofNat]
       rw [setWidth_ofNat_one_eq_ofNat_one_of_lt (by omega)]
       simp
     case neg hy =>
-      simp [hy, setWidth_one]
+      simp [hy, setWidth_one_eq_ofBool_getLsb_zero]
   case succ s' hs =>
     rw [mulRec_succ_eq, hs]
     have heq :
@@ -835,7 +836,7 @@ execution. -/
 structure DivModArgs (w : Nat) where
   /-- the numerator (aka, dividend) -/
   n : BitVec w
-  /-- the denominator (aka, divisor)-/
+  /-- the denumerator (aka, divisor)-/
   d : BitVec w
 
 /-- A `DivModState` is lawful if the remainder width `wr` plus the numerator width `wn` equals `w`,
@@ -1024,7 +1025,7 @@ theorem lawful_divSubtractShift (qr : DivModState w) (h : qr.Poised args) :
     case neg.hrWidth =>
       simp only
       have hdr' : d ≤ (qr.r.shiftConcat (n.getLsbD (qr.wn - 1))) :=
-        BitVec.not_lt.mp rltd
+        BitVec.not_lt_iff_le.mp rltd
       have hr' : ((qr.r.shiftConcat (n.getLsbD (qr.wn - 1)))).toNat < 2 ^ (qr.wr + 1) := by
         apply toNat_shiftConcat_lt_of_lt <;> bv_omega
       rw [BitVec.toNat_sub_of_le hdr']
@@ -1032,7 +1033,7 @@ theorem lawful_divSubtractShift (qr : DivModState w) (h : qr.Poised args) :
     case neg.hqWidth =>
       apply toNat_shiftConcat_lt_of_lt <;> omega
     case neg.hdiv =>
-      have rltd' := (BitVec.not_lt.mp rltd)
+      have rltd' := (BitVec.not_lt_iff_le.mp rltd)
       simp only [qr.toNat_shiftRight_sub_one_eq h,
         BitVec.toNat_sub_of_le rltd',
         toNat_shiftConcat_eq_of_lt (qr.wr_lt_w h) h.hrWidth]
@@ -1406,7 +1407,7 @@ theorem eq_iff_eq_of_inv (f : α → BitVec w) (g : BitVec w → α) (h : ∀ x,
     have := congrArg g h'
     simpa [h] using this
 
-@[deprecated BitVec.ne_intMin_of_msb_eq_false (since := "2025-10-26")]
+@[simp]
 theorem ne_intMin_of_lt_of_msb_false {x : BitVec w} (hw : 0 < w) (hx : x.msb = false) :
     x ≠ intMin w := by
   have := toNat_lt_of_msb_false hx
@@ -1511,7 +1512,7 @@ theorem sdiv_ne_intMin_of_ne_intMin {x y : BitVec w} (h : x ≠ intMin w) :
   by_cases hx : x.msb <;> by_cases hy : y.msb
   <;> simp only [hx, hy, neg_ne_intMin_inj]
   <;> simp only [Bool.not_eq_true] at hx hy
-  <;> apply ne_intMin_of_msb_eq_false (by omega)
+  <;> apply ne_intMin_of_lt_of_msb_false (by omega)
   <;> rw [msb_udiv]
   <;> try simp only [hx, Bool.false_and]
   · simp [h, ne_zero_of_msb_true, hx]
@@ -1623,7 +1624,7 @@ theorem toInt_sdiv_of_ne_or_ne (a b : BitVec w) (h : a ≠ intMin w ∨ b ≠ -1
             · have ry := (intMin_udiv_eq_intMin_iff b).mp
               simp only [hb1, imp_false] at ry
               simp [msb_udiv, ha_intMin, hb1, ry, intMin_udiv_ne_zero_of_ne_zero, hb, hb0]
-            · have := @BitVec.ne_intMin_of_msb_eq_false w wpos ((-a) / b) (by simp [ha, ha0, ha_intMin])
+            · have := @BitVec.ne_intMin_of_lt_of_msb_false w ((-a) / b) wpos (by simp [ha, ha0, ha_intMin])
               simp [msb_neg, h', this, ha, ha_intMin]
       rw [toInt_eq_toNat_of_msb hb, toInt_eq_neg_toNat_neg_of_msb_true ha, Int.neg_tdiv,
         Int.tdiv_eq_ediv_of_nonneg (by omega), sdiv_toInt_of_msb_true_of_msb_false]
@@ -1634,7 +1635,7 @@ theorem toInt_sdiv_of_ne_or_ne (a b : BitVec w) (h : a ≠ intMin w ∨ b ≠ -1
         rw [toInt_udiv_of_msb ha, toInt_eq_toNat_of_msb ha]
         rw [toInt_eq_neg_toNat_neg_of_msb_true hb, Int.tdiv_neg, Int.tdiv_eq_ediv_of_nonneg (by omega)]
       · apply sdiv_ne_intMin_of_ne_intMin
-        apply ne_intMin_of_msb_eq_false (by omega) ha
+        apply ne_intMin_of_lt_of_msb_false (by omega) ha
     · rw [sdiv, Int.tdiv_cases, udiv_eq, neg_eq, if_pos (toInt_nonneg_of_msb_false ha),
         if_pos (toInt_nonneg_of_msb_false hb), ha, hb, toInt_udiv_of_msb ha,
         toInt_eq_toNat_of_msb ha, toInt_eq_toNat_of_msb hb]
@@ -1926,7 +1927,7 @@ theorem toInt_sub_neg_umod {x y : BitVec w} (hxmsb : x.msb = true) (hymsb : y.ms
       rw [Int.bmod_eq_of_le (by omega) (by omega)]
       simp only [toInt_eq_toNat_of_msb hymsb, BitVec.toInt_eq_neg_toNat_neg_of_msb_true hxmsb,
         Int.dvd_neg] at hdvd
-      simp only [hdvd, ↓reduceIte, Int.natAbs_natCast]
+      simp only [hdvd, ↓reduceIte, Int.natAbs_cast]
 
 theorem srem_zero_of_dvd {x y : BitVec w} (h : y.toInt ∣ x.toInt) :
     x.srem y = 0#w := by

src/Init/Data/BitVec/Folds.lean

@@ -82,7 +82,7 @@ theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
       intro i
       simp only [getLsbD_cons]
       have hj2 : j.val ≤ w := by simp
-      cases (Nat.lt_or_eq_of_le (Nat.lt_succ_iff.mp i.isLt)) with
+      cases (Nat.lt_or_eq_of_le (Nat.lt_succ.mp i.isLt)) with
       | inl h3 => simp [(Nat.ne_of_lt h3)]
                   exact (ih hj2).1 ⟨i.val, h3⟩
       | inr h3 => simp [h3]

src/Init/Data/BitVec/Lemmas.lean

@@ -34,6 +34,14 @@ namespace BitVec
   simp only [Bool.and_eq_false_imp, decide_eq_true_eq]
   omega
 
+set_option linter.missingDocs false in
+@[deprecated getLsbD_of_ge (since := "2025-04-04")]
+abbrev getLsbD_ge := @getLsbD_of_ge
+
+set_option linter.missingDocs false in
+@[deprecated getMsbD_of_ge (since := "2025-04-04")]
+abbrev getMsbD_ge := @getMsbD_of_ge
+
 theorem lt_of_getLsbD {x : BitVec w} {i : Nat} : getLsbD x i = true → i < w := by
   if h : i < w then
     simp [h]
@@ -64,12 +72,8 @@ theorem getElem?_eq_none_iff {l : BitVec w} : l[n]? = none ↔ w ≤ n := by
 theorem none_eq_getElem?_iff {l : BitVec w} : none = l[n]? ↔ w ≤ n := by
   simp
 
-@[simp]
 theorem getElem?_eq_none {l : BitVec w} (h : w ≤ n) : l[n]? = none := getElem?_eq_none_iff.mpr h
 
-grind_pattern BitVec.getElem?_eq_none => l[n]? where
-  guard w ≤ n
-
 theorem getElem?_eq (l : BitVec w) (i : Nat) :
     l[i]? = if h : i < w then some l[i] else none := by
   split <;> simp_all
@@ -136,6 +140,9 @@ theorem two_pow_le_toNat_of_getElem_eq_true {i : Nat} {x : BitVec w}
   rw [← getElem_eq_testBit_toNat x i hi]
   exact hx
 
+@[grind =] theorem msb_eq_getMsbD (x : BitVec w) : x.msb = x.getMsbD 0 := by
+  simp [BitVec.msb]
+
 @[grind =] theorem getMsb_eq_getLsb (x : BitVec w) (i : Fin w) :
     x.getMsb i = x.getLsb ⟨w - 1 - i, by omega⟩ := by
   simp only [getMsb, getLsb]
@@ -148,6 +155,10 @@ theorem two_pow_le_toNat_of_getElem_eq_true {i : Nat} {x : BitVec w}
 @[grind =] theorem getMsbD_eq_getLsbD (x : BitVec w) (i : Nat) : x.getMsbD i = (decide (i < w) && x.getLsbD (w - 1 - i)) := by
   rw [getMsbD, getLsbD]
 
+@[deprecated getMsb_eq_getLsb (since := "2025-06-17")]
+theorem getMsb'_eq_getLsb' (x : BitVec w) (i : Nat) : x.getMsbD i = (decide (i < w) && x.getLsbD (w - 1 - i)) := by
+  rw [getMsbD, getLsbD]
+
 theorem getLsbD_eq_getMsbD (x : BitVec w) (i : Nat) : x.getLsbD i = (decide (i < w) && x.getMsbD (w - 1 - i)) := by
   rw [getMsbD]
   by_cases h₁ : i < w <;> by_cases h₂ : w - 1 - i < w <;>
@@ -158,13 +169,18 @@ theorem getLsbD_eq_getMsbD (x : BitVec w) (i : Nat) : x.getLsbD i = (decide (i <
     apply getLsbD_of_ge
     omega
 
-@[deprecated getElem?_eq_none (since := "2025-10-29")]
-theorem getElem?_of_ge (x : BitVec w) (i : Nat) (ge : w ≤ i) : x[i]? = none := by
+@[simp] theorem getElem?_of_ge (x : BitVec w) (i : Nat) (ge : w ≤ i) : x[i]? = none := by
   simp [ge]
 
 @[simp] theorem getMsb?_of_ge (x : BitVec w) (i : Nat) (ge : w ≤ i) : getMsb? x i = none := by
   simp [getMsb?_eq_getLsb?]; omega
 
+set_option linter.missingDocs false in
+@[deprecated getElem?_of_ge (since := "2025-04-04")] abbrev getLsb?_ge := @getElem?_of_ge
+
+set_option linter.missingDocs false in
+@[deprecated getMsb?_of_ge (since := "2025-04-04")] abbrev getMsb?_ge := @getMsb?_of_ge
+
 theorem lt_of_getElem?_eq_some (x : BitVec w) (i : Nat) : x[i]? = some b → i < w := by
   cases h : x[i]? with
   | none => simp
@@ -187,6 +203,18 @@ theorem lt_of_isSome_getMsb? (x : BitVec w) (i : Nat) : (getMsb? x i).isSome →
   else
     simp [Nat.ge_of_not_lt h]
 
+set_option linter.missingDocs false in
+@[deprecated lt_of_getElem?_eq_some (since := "2025-04-04")]
+abbrev lt_of_getLsb?_eq_some := @lt_of_getElem?_eq_some
+
+set_option linter.missingDocs false in
+@[deprecated lt_of_isSome_getElem? (since := "2025-04-04")]
+abbrev lt_of_getLsb?_isSome := @lt_of_isSome_getElem?
+
+set_option linter.missingDocs false in
+@[deprecated lt_of_isSome_getMsb? (since := "2025-04-04")]
+abbrev lt_of_getMsb?_isSome := @lt_of_isSome_getMsb?
+
 theorem getMsbD_eq_getMsb?_getD (x : BitVec w) (i : Nat) :
     x.getMsbD i = (x.getMsb? i).getD false := by
   rw [getMsbD_eq_getLsbD]
@@ -416,18 +444,12 @@ theorem getElem?_zero_ofNat_one : (BitVec.ofNat (w+1) 1)[0]? = some true := by
 
 -- This does not need to be a `@[simp]` theorem as it is already handled by `getElem?_eq_getElem`.
 theorem getElem?_zero_ofBool (b : Bool) : (ofBool b)[0]? = some b := by
-  simp only [ofBool, ofNat_eq_ofNat, cond_eq_ite]
+  simp only [ofBool, ofNat_eq_ofNat, cond_eq_if]
   split <;> simp_all
 
-@[simp, grind =]
-theorem getElem_ofBool_zero {b : Bool} : (ofBool b)[0] = b := by
+@[simp, grind =] theorem getElem_zero_ofBool (b : Bool) : (ofBool b)[0] = b := by
   rw [getElem_eq_iff, getElem?_zero_ofBool]
 
-
-@[deprecated getElem_ofBool_zero (since := "2025-10-29")]
-theorem getElem_zero_ofBool (b : Bool) : (ofBool b)[0] = b := by
-  simp
-
 theorem getElem?_succ_ofBool (b : Bool) (i : Nat) : (ofBool b)[i + 1]? = none := by
   simp
 
@@ -438,6 +460,8 @@ theorem getLsbD_ofBool (b : Bool) (i : Nat) : (ofBool b).getLsbD i = ((i = 0) &&
   · simp only [ofBool, ofNat_eq_ofNat, cond_true, getLsbD_ofNat, Bool.and_true]
     by_cases hi : i = 0 <;> simp [hi] <;> omega
 
+theorem getElem_ofBool_zero {b : Bool} : (ofBool b)[0] = b := by simp
+
 @[simp]
 theorem getElem_ofBool {b : Bool} {h : i < 1}: (ofBool b)[i] = b := by
   simp [← getLsbD_eq_getElem]
@@ -520,10 +544,6 @@ theorem toNat_ge_of_msb_true {x : BitVec n} (p : BitVec.msb x = true) : x.toNat
 @[grind _=_] theorem msb_eq_getMsbD_zero (x : BitVec w) : x.msb = x.getMsbD 0 := by
   cases w <;> simp [getMsbD_eq_getLsbD, msb_eq_getLsbD_last]
 
-@[deprecated msb_eq_getMsbD_zero (since := "2025-10-26")]
-theorem msb_eq_getMsbD (x : BitVec w) : x.msb = x.getMsbD 0 := by
-  simp [BitVec.msb]
-
 /-! ### cast -/
 
 @[simp, grind =] theorem toFin_cast (h : w = v) (x : BitVec w) :
@@ -585,7 +605,7 @@ theorem toInt_eq_toNat_bmod (x : BitVec n) : x.toInt = Int.bmod x.toNat (2^n) :=
   simp only [toInt_eq_toNat_cond]
   split
   next g =>
-    rw [Int.bmod_eq_emod_of_lt] <;> simp only [←Int.natCast_emod, toNat_mod_cancel]
+    rw [Int.bmod_pos] <;> simp only [←Int.natCast_emod, toNat_mod_cancel]
     omega
   next g =>
     rw [Int.bmod_neg] <;> simp only [←Int.natCast_emod, toNat_mod_cancel]
@@ -993,14 +1013,7 @@ theorem msb_setWidth' (x : BitVec w) (h : w ≤ v) : (x.setWidth' h).msb = (deci
 theorem msb_setWidth'' (x : BitVec w) : (x.setWidth (k + 1)).msb = x.getLsbD k := by
   simp [BitVec.msb, getMsbD]
 
-/-- Truncating to width 1 produces a bitvector equal to the least significant bit. -/
-theorem setWidth_one {x : BitVec w} :
-    x.setWidth 1 = ofBool (x.getLsbD 0) := by
-  ext i
-  simp [show i = 0 by omega]
-
 /-- zero extending a bitvector to width 1 equals the boolean of the lsb. -/
-@[deprecated setWidth_one (since := "2025-10-29")]
 theorem setWidth_one_eq_ofBool_getLsb_zero (x : BitVec w) :
     x.setWidth 1 = BitVec.ofBool (x.getLsbD 0) := by
   ext i h
@@ -1016,20 +1029,18 @@ theorem setWidth_ofNat_one_eq_ofNat_one_of_lt {v w : Nat} (hv : 0 < v) :
   have hv := (@Nat.testBit_one_eq_true_iff_self_eq_zero i)
   by_cases h : Nat.testBit 1 i = true <;> simp_all
 
+/-- Truncating to width 1 produces a bitvector equal to the least significant bit. -/
+theorem setWidth_one {x : BitVec w} :
+    x.setWidth 1 = ofBool (x.getLsbD 0) := by
+  ext i
+  simp [show i = 0 by omega]
+
 @[simp, grind =] theorem setWidth_ofNat_of_le (h : v ≤ w) (x : Nat) : setWidth v (BitVec.ofNat w x) = BitVec.ofNat v x := by
   apply BitVec.eq_of_toNat_eq
   simp only [toNat_setWidth, toNat_ofNat]
   rw [Nat.mod_mod_of_dvd]
   exact Nat.pow_dvd_pow_iff_le_right'.mpr h
 
-@[simp]
-theorem setWidth_ofNat_of_le_of_lt {x : Nat} (h : w ≤ v) (h' : x < 2 ^ w) :
-    setWidth v (BitVec.ofNat w x) = BitVec.ofNat v x := by
-  apply BitVec.eq_of_toNat_eq
-  have := Nat.pow_le_pow_of_le (a := 2) (m := v) (n := w) (by omega) h
-  simp only [toNat_setWidth, toNat_ofNat]
-  rw [Nat.mod_eq_of_lt (by omega), Nat.mod_eq_of_lt (by omega), Nat.mod_eq_of_lt (by omega)]
-
 /--
 Iterated `setWidth` agrees with the second `setWidth`
 except in the case the first `setWidth` is a non-trivial truncation,
@@ -1063,7 +1074,7 @@ theorem toInt_setWidth' {m n : Nat} (p : m ≤ n) {x : BitVec m} :
 @[simp, grind =] theorem toFin_setWidth' {m n : Nat} (p : m ≤ n) (x : BitVec m) :
     (setWidth' p x).toFin = x.toFin.castLE (Nat.pow_le_pow_right (by omega) (by omega)) := by
   ext
-  rw [setWidth'_eq, toFin_setWidth, Fin.val_ofNat, Fin.val_castLE, val_toFin,
+  rw [setWidth'_eq, toFin_setWidth, Fin.val_ofNat, Fin.coe_castLE, val_toFin,
     Nat.mod_eq_of_lt (by apply BitVec.toNat_lt_twoPow_of_le p)]
 
 theorem toNat_setWidth_of_le {w w' : Nat} {b : BitVec w} (h : w ≤ w') : (b.setWidth w').toNat = b.toNat := by
@@ -1197,7 +1208,7 @@ let x' = x.extractLsb' 7 5  =   _ _ 9 8 7
 
 @[simp] theorem getLsbD_extract (hi lo : Nat) (x : BitVec n) (i : Nat) :
     getLsbD (extractLsb hi lo x) i = (i ≤ (hi-lo) && getLsbD x (lo+i)) := by
-  simp [getLsbD, Nat.lt_succ_iff]
+  simp [getLsbD, Nat.lt_succ]
 
 @[simp] theorem getLsbD_extractLsb {hi lo : Nat} {x : BitVec n} {i : Nat} :
     (extractLsb hi lo x).getLsbD i = (decide (i < hi - lo + 1) && x.getLsbD (lo + i)) := by
@@ -1263,31 +1274,11 @@ theorem extractLsb'_setWidth_of_le {b : BitVec w} {start len w' : Nat} (h : star
   simp
   omega
 
-@[simp]
-theorem extractLsb_setWidth_of_lt {x : BitVec w} {hi lo v : Nat} (h : lo + hi < v) :
-    (x.setWidth v).extractLsb hi lo = x.extractLsb hi lo := by
-  simp only [BitVec.extractLsb]
-  ext k hk
-  simp
-  omega
-
 theorem setWidth_extractLsb'_of_le {c : BitVec w} (h : len₁ ≤ len₂) :
     (c.extractLsb' start len₂).setWidth len₁ = c.extractLsb' start len₁ := by
   ext i hi
   simp [show i < len₂ by omega]
 
-theorem extractLsb'_cast {x : BitVec w} :
-    (x.cast hcast).extractLsb' start len = x.extractLsb' start len := by
-  ext k hk
-  simp
-
-@[simp]
-theorem extractLsb'_extractLsb'_of_le {x : BitVec w} (hlt : start + len ≤ len') :
-    (x.extractLsb' 0 len').extractLsb' start len  = x.extractLsb' start len := by
-  ext k hk
-  simp
-  omega
-
 /-! ### allOnes -/
 
 @[simp, grind =] theorem toNat_allOnes : (allOnes v).toNat = 2^v - 1 := by
@@ -1673,11 +1664,11 @@ theorem not_def {x : BitVec v} : ~~~x = allOnes v ^^^ x := rfl
 
 @[simp] theorem ofInt_negSucc_eq_not_ofNat {w n : Nat} :
     BitVec.ofInt w (Int.negSucc n) = ~~~.ofNat w n := by
-  simp only [BitVec.ofInt, Int.toNat, Int.ofNat_eq_natCast, toNat_eq, toNat_ofNatLT, toNat_not,
+  simp only [BitVec.ofInt, Int.toNat, Int.ofNat_eq_coe, toNat_eq, toNat_ofNatLT, toNat_not,
     toNat_ofNat]
   cases h : Int.negSucc n % ((2 ^ w : Nat) : Int)
   case ofNat =>
-    rw [Int.ofNat_eq_natCast, Int.negSucc_emod] at h
+    rw [Int.ofNat_eq_coe, Int.negSucc_emod] at h
     · dsimp only
       omega
     · omega
@@ -1759,6 +1750,9 @@ theorem not_eq_comm {x y : BitVec w} : ~~~ x = y ↔ x = ~~~ y := by
     rw [h]
     simp
 
+set_option linter.missingDocs false in
+@[deprecated getMsbD_not (since := "2025-04-04")] abbrev getMsb_not := @getMsbD_not
+
 @[simp] theorem msb_not {x : BitVec w} : (~~~x).msb = (decide (0 < w) && !x.msb) := by
   simp [BitVec.msb]
 
@@ -2578,6 +2572,10 @@ theorem signExtend_eq_setWidth_of_le (x : BitVec w) {v : Nat} (hv : v ≤ w) :
   ext i h
   simp [getElem_signExtend, show i < w by omega]
 
+@[deprecated signExtend_eq_setWidth_of_le (since := "2025-03-07")]
+theorem signExtend_eq_setWidth_of_lt (x : BitVec w) {v : Nat} (hv : v ≤ w) :
+  x.signExtend v = x.setWidth v := signExtend_eq_setWidth_of_le x hv
+
 /-- Sign extending to the same bitwidth is a no op. -/
 @[simp] theorem signExtend_eq (x : BitVec w) : x.signExtend w = x := by
   rw [signExtend_eq_setWidth_of_le _ (Nat.le_refl _), setWidth_eq]
@@ -2944,15 +2942,6 @@ theorem setWidth_eq_append {v : Nat} {x : BitVec v} {w : Nat} (h : v ≤ w) :
     omega
   · simp [hiv, getLsbD_of_ge x i (by omega)]
 
-@[simp]
-theorem extractLsb'_append_extractLsb' {x : BitVec (w + len)} :
-    (x.extractLsb' len w ++ x.extractLsb' 0 len) = x := by
-  ext i hi
-  simp only [getElem_append, getElem_extractLsb', Nat.zero_add, dite_eq_ite]
-  split
-  · rw [← getLsbD_eq_getElem]
-  · simp [show len + (i - len) = i by omega, ← getLsbD_eq_getElem]
-
 theorem setWidth_eq_extractLsb' {v : Nat} {x : BitVec v} {w : Nat} (h : w ≤ v) :
     x.setWidth w = x.extractLsb' 0 w := by
   rw [setWidth_eq_append_extractLsb']
@@ -3250,11 +3239,6 @@ theorem cons_append_append (x : BitVec w₁) (y : BitVec w₂) (z : BitVec w₃)
     · simp [h₂]; omega
     · simp [h₂];  omega
 
-@[simp]
-theorem extractLsb'_cons {x : BitVec w} :
-    (x.cons y).extractLsb' 0 w = x := by
-  simp [BitVec.toNat_eq, Nat.or_mod_two_pow, Nat.shiftLeft_eq]
-
 /-! ### concat -/
 
 @[simp, grind =] theorem toNat_concat (x : BitVec w) (b : Bool) :
@@ -3353,15 +3337,6 @@ theorem msb_concat {w : Nat} {b : Bool} {x : BitVec w} :
   ext
   simp [getElem_concat]
 
-theorem extractLsb'_concat {x : BitVec (w + 1)} {y : Bool} :
-    (x.concat y).extractLsb' 0 (t + 1) = (x.extractLsb' 0 t).concat y := by
-  ext i hi
-  simp only [← getLsbD_eq_getElem, getLsbD_extractLsb', hi, decide_true, Nat.zero_add,
-    getLsbD_concat, Bool.true_and]
-  split
-  · simp
-  · simp [show i - 1 < t by omega]
-
 /-! ### shiftConcat -/
 
 @[grind =]
@@ -3660,6 +3635,9 @@ theorem sub_eq_add_neg {n} (x y : BitVec n) : x - y = x + - y := by
   simp only [toNat_sub, toNat_add, toNat_neg, Nat.add_mod_mod]
   rw [Nat.add_comm]
 
+set_option linter.missingDocs false in
+@[deprecated sub_eq_add_neg (since := "2025-04-04")] abbrev sub_toAdd := @sub_eq_add_neg
+
 theorem add_left_neg (x : BitVec w) : -x + x = 0#w := by
   apply toInt_inj.mp
   simp [toInt_neg, Int.add_left_neg]
@@ -3699,6 +3677,10 @@ theorem neg_one_eq_allOnes : -1#w = allOnes w := by
     have r : (2^w - 1) < 2^w := by omega
     simp [Nat.mod_eq_of_lt q, Nat.mod_eq_of_lt r]
 
+set_option linter.missingDocs false in
+@[deprecated neg_one_eq_allOnes (since := "2025-04-04")]
+abbrev negOne_eq_allOnes := @neg_one_eq_allOnes
+
 theorem neg_eq_not_add (x : BitVec w) : -x = ~~~x + 1#w := by
   apply eq_of_toNat_eq
   simp only [toNat_neg, toNat_add, toNat_not, toNat_ofNat, Nat.add_mod_mod]
@@ -4115,7 +4097,6 @@ protected theorem umod_lt (x : BitVec n) {y : BitVec n} : 0 < y → x % y < y :=
   simp only [ofNat_eq_ofNat, lt_def, toNat_ofNat, Nat.zero_mod]
   apply Nat.mod_lt
 
-@[deprecated BitVec.not_lt (since := "2025-10-26")]
 theorem not_lt_iff_le {x y : BitVec w} : (¬ x < y) ↔ y ≤ x := by
   constructor <;>
     (intro h; simp only [lt_def, Nat.not_lt, le_def] at h ⊢; omega)
@@ -4132,7 +4113,7 @@ theorem not_lt_zero {x : BitVec w} : ¬x < 0#w := of_decide_eq_false rfl
 theorem le_zero_iff {x : BitVec w} : x ≤ 0#w ↔ x = 0#w := by
   constructor
   · intro h
-    have : x ≥ 0 := BitVec.not_lt.mp not_lt_zero
+    have : x ≥ 0 := not_lt_iff_le.mp not_lt_zero
     exact Eq.symm (BitVec.le_antisymm this h)
   · simp_all
 
@@ -4155,7 +4136,7 @@ theorem not_allOnes_lt {x : BitVec w} : ¬allOnes w < x := by
 theorem allOnes_le_iff {x : BitVec w} : allOnes w ≤ x ↔ x = allOnes w := by
   constructor
   · intro h
-    have : x ≤ allOnes w := BitVec.not_lt.mp not_allOnes_lt
+    have : x ≤ allOnes w := not_lt_iff_le.mp not_allOnes_lt
     exact Eq.symm (BitVec.le_antisymm h this)
   · simp_all
 
@@ -4701,6 +4682,9 @@ theorem zero_smod {x : BitVec w} : (0#w).smod x = 0#w := by
 @[simp, grind =] theorem getLsbD_ofBoolListLE : (ofBoolListLE bs).getLsbD i = bs.getD i false := by
   induction bs generalizing i <;> cases i <;> simp_all [ofBoolListLE]
 
+set_option linter.missingDocs false in
+@[deprecated getLsbD_ofBoolListLE (since := "2025-04-04")] abbrev getLsb_ofBoolListLE := @getLsbD_ofBoolListLE
+
 @[simp, grind =] theorem getMsbD_ofBoolListLE :
     (ofBoolListLE bs).getMsbD i = (decide (i < bs.length) && bs.getD (bs.length - 1 - i) false) := by
   simp [getMsbD_eq_getLsbD]
@@ -4771,6 +4755,14 @@ theorem getLsbD_rotateLeftAux_of_ge {x : BitVec w} {r : Nat} {i : Nat} (hi : i
   apply getLsbD_of_ge
   omega
 
+set_option linter.missingDocs false in
+@[deprecated getLsbD_rotateLeftAux_of_lt (since := "2025-04-04")]
+abbrev getLsbD_rotateLeftAux_of_le := @getLsbD_rotateLeftAux_of_lt
+
+set_option linter.missingDocs false in
+@[deprecated getLsbD_rotateLeftAux_of_ge (since := "2025-04-04")]
+abbrev getLsbD_rotateLeftAux_of_geq := @getLsbD_rotateLeftAux_of_ge
+
 /-- When `r < w`, we give a formula for `(x.rotateLeft r).getLsbD i`. -/
 theorem getLsbD_rotateLeft_of_le {x : BitVec w} {r i : Nat} (hr: r < w) :
     (x.rotateLeft r).getLsbD i =
@@ -4927,6 +4919,14 @@ theorem getLsbD_rotateRightAux_of_ge {x : BitVec w} {r : Nat} {i : Nat} (hi : i
   apply getLsbD_of_ge
   omega
 
+set_option linter.missingDocs false in
+@[deprecated getLsbD_rotateRightAux_of_lt (since := "2025-04-04")]
+abbrev getLsbD_rotateRightAux_of_le := @getLsbD_rotateRightAux_of_lt
+
+set_option linter.missingDocs false in
+@[deprecated getLsbD_rotateRightAux_of_ge (since := "2025-04-04")]
+abbrev getLsbD_rotateRightAux_of_geq := @getLsbD_rotateRightAux_of_ge
+
 /-- `rotateRight` equals the bit fiddling definition of `rotateRightAux` when the rotation amount is
 smaller than the bitwidth. -/
 theorem rotateRight_eq_rotateRightAux_of_lt {x : BitVec w} {r : Nat} (hr : r < w) :
@@ -5651,7 +5651,7 @@ theorem msb_eq_toNat {x : BitVec w}:
   simp only [msb_eq_decide, ge_iff_le]
 
 /-- Negating a bitvector created from a natural number equals
-creating a bitvector from the negative of that number.
+creating a bitvector from the the negative of that number.
 -/
 theorem neg_ofNat_eq_ofInt_neg {w : Nat} {x : Nat} :
     - BitVec.ofNat w x = BitVec.ofInt w (- x) := by
@@ -5866,16 +5866,6 @@ theorem reverse_reverse_eq {x : BitVec w} :
   ext k hk
   rw [getElem_reverse, getMsbD_reverse, getLsbD_eq_getElem]
 
-@[simp]
-theorem concat_reverse_setWidth_msb_eq_reverse {x : BitVec (w + 1)} :
-    concat ((x.setWidth w).reverse) x.msb = x.reverse := by
-  ext i hi
-  simp only [getElem_reverse, BitVec.msb, getElem_concat, getMsbD_setWidth, Nat.le_add_right,
-    Nat.sub_eq_zero_of_le, Nat.zero_le, decide_true, Bool.true_and, dite_eq_ite]
-  by_cases hzero : i = 0
-  · simp [hzero]
-  · simp [hzero, show i - 1 + (w + 1) - w = i by omega]
-
 /-! ### Inequalities (le / lt) -/
 
 theorem ule_eq_not_ult (x y : BitVec w) : x.ule y = !y.ult x := by
@@ -6351,241 +6341,4 @@ theorem two_pow_ctz_le_toNat_of_ne_zero {x : BitVec w} (hx : x ≠ 0#w) :
   have hclz := getLsbD_true_ctz_of_ne_zero (x := x) hx
   exact Nat.ge_two_pow_of_testBit hclz
 
-/-! ### Population Count -/
-
-@[simp]
-theorem cpopNatRec_zero_self {x : BitVec w} :
-    x.cpopNatRec 0 acc = acc := rfl
-
-@[simp]
-theorem cpopNatRec_succ {n : Nat} {x : BitVec w} :
-    x.cpopNatRec (n + 1) acc = x.cpopNatRec n (acc + (x.getLsbD n).toNat) := rfl
-
-@[simp]
-theorem cpopNatRec_zero :
-    (0#w).cpopNatRec n acc = acc := by
-  induction n
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    simp [ihn]
-
-theorem cpopNatRec_eq {x : BitVec w} {n : Nat} (acc : Nat):
-    x.cpopNatRec n acc = x.cpopNatRec n 0 + acc := by
-  induction n generalizing acc
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    simp [ihn (acc := acc + (x.getLsbD n).toNat), ihn (acc := (x.getLsbD n).toNat)]
-    omega
-
-theorem cpopNatRec_add {x : BitVec w} {acc n : Nat} :
-    x.cpopNatRec n (acc + acc') = x.cpopNatRec n acc + acc' := by
-  rw [cpopNatRec_eq (acc := acc + acc'), cpopNatRec_eq (acc := acc), Nat.add_assoc]
-
-theorem cpopNatRec_le {x : BitVec w} (n : Nat) :
-    x.cpopNatRec n acc ≤ acc + n := by
-  induction n generalizing acc
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    have : (x.getLsbD n).toNat ≤ 1 := by cases x.getLsbD n <;> simp
-    specialize ihn (acc := acc + (x.getLsbD n).toNat)
-    simp
-    omega
-
-@[simp]
-theorem cpopNatRec_of_le {x : BitVec w} (k n : Nat) (hn : w ≤ n) :
-    x.cpopNatRec (n + k) acc = x.cpopNatRec n acc := by
-  induction k
-  · case zero =>
-    simp
-  · case succ k ihk =>
-    simp [show n + (k + 1) = (n + k) + 1 by omega, ihk, show w ≤ n + k by omega]
-
-theorem cpopNatRec_zero_le (x : BitVec w) (n : Nat) :
-    x.cpopNatRec n 0 ≤ w := by
-  induction n
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    by_cases hle : n ≤ w
-    · by_cases hx : x.getLsbD n
-      · have := cpopNatRec_le (x := x) (acc := 1) (by omega)
-        have := lt_of_getLsbD hx
-        simp [hx]
-        omega
-      · have := cpopNatRec_le (x := x) (acc := 0) (by omega)
-        simp [hx]
-        omega
-    · simp [show w ≤ n by omega]
-      omega
-
-@[simp]
-theorem cpopNatRec_allOnes (h : n ≤ w) :
-    (allOnes w).cpopNatRec n acc = acc + n := by
-  induction n
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    specialize ihn (by omega)
-    simp [show n < w by omega, ihn,
-      cpopNatRec_add (acc := acc) (acc' := 1)]
-    omega
-
-@[simp]
-theorem cpop_allOnes :
-    (allOnes w).cpop = BitVec.ofNat w w := by
-  simp [cpop, cpopNatRec_allOnes]
-
-@[simp]
-theorem cpop_zero :
-    (0#w).cpop = 0#w := by
-  simp [cpop]
-
-theorem toNat_cpop_le (x : BitVec w) :
-    x.cpop.toNat ≤ w := by
-  have hlt := Nat.lt_two_pow_self (n := w)
-  have hle := cpopNatRec_zero_le (x := x) (n := w)
-  simp only [cpop, toNat_ofNat, ge_iff_le]
-  rw [Nat.mod_eq_of_lt (by omega)]
-  exact hle
-
-@[simp]
-theorem cpopNatRec_cons_of_le {x : BitVec w} {b : Bool} (hn : n ≤ w) :
-    (cons b x).cpopNatRec n acc = x.cpopNatRec n acc := by
-  induction n generalizing acc
-  · case zero =>
-    simp
-  · case succ n ihn =>
-    specialize ihn (acc := acc + ((cons b x).getLsbD n).toNat) (by omega)
-    rw [cpopNatRec_succ, ihn, getLsbD_cons]
-    simp [show ¬ n = w by omega]
-
-@[simp]
-theorem cpopNatRec_cons_of_lt {x : BitVec w} {b : Bool} (hn : w < n) :
-    (cons b x).cpopNatRec n acc = b.toNat + x.cpopNatRec n acc := by
-  induction n generalizing acc
-  · case zero =>
-    omega
-  · case succ n ihn =>
-    by_cases hlt : w < n
-    · rw [cpopNatRec_succ, ihn (acc := acc + ((cons b x).getLsbD n).toNat) (by omega)]
-      simp [getLsbD_cons, show ¬ n = w by omega]
-    · simp [show w = n by omega, getElem_cons,
-        cpopNatRec_add (acc := acc) (acc' := b.toNat), Nat.add_comm]
-
-theorem cpopNatRec_concat_of_lt {x : BitVec w} {b : Bool} (hn : 0 < n) :
-    (concat x b).cpopNatRec n acc = b.toNat + x.cpopNatRec (n - 1) acc := by
-  induction n generalizing acc
-  · case zero =>
-    omega
-  · case succ n ihn =>
-    by_cases hn0 : 0 < n
-    · specialize ihn (acc := (acc + ((x.concat b).getLsbD n).toNat)) (by omega)
-      rw [cpopNatRec_succ, ihn, cpopNatRec_add (acc := acc)]
-      simp [getLsbD_concat, show ¬ n = 0 by omega, show n + 1 - 1 = n - 1 + 1 by omega, cpopNatRec_add]
-    · simp [show n = 0 by omega]
-      omega
-
-theorem toNat_cpop (x : BitVec w) :
-    x.cpop.toNat = x.cpopNatRec w 0 := by
-  have := cpopNatRec_zero_le x w
-  have := toNat_cpop_le x
-  have := Nat.lt_two_pow_self (n := w)
-  rw [cpop, toNat_ofNat, Nat.mod_eq_of_lt]
-  omega
-
-@[simp]
-theorem toNat_cpop_cons {x : BitVec w} {b : Bool} :
-    (x.cons b).cpop.toNat = b.toNat + x.cpop.toNat := by
-  simp [toNat_cpop, getElem_cons, cpopNatRec_eq (acc := b.toNat), Nat.add_comm]
-
-@[simp]
-theorem cpopNatRec_setWidth_of_le (x : BitVec w) (h : pos ≤ v) :
-    (setWidth v x).cpopNatRec pos acc = x.cpopNatRec pos acc := by
-  induction pos generalizing acc
-  · case zero =>
-    simp
-  · case succ pos ih =>
-    simp only [cpopNatRec_succ, getLsbD_setWidth]
-    rw [ih]
-    · congr
-      by_cases h : pos < v
-      <;> simp [h]
-      omega
-    · omega
-
-theorem cpop_cons {x : BitVec w} {b : Bool} :
-    (x.cons b).cpop = b.toNat + x.cpop.setWidth (w + 1) := by
-  have := toNat_cpop_le x
-  have := Bool.toNat_lt b
-  simp only [natCast_eq_ofNat, toNat_eq, toNat_add, toNat_ofNat, toNat_setWidth, Nat.lt_add_one,
-    toNat_mod_cancel_of_lt, Nat.mod_add_mod]
-  rw [toNat_cpop_cons, Nat.mod_eq_of_lt]
-  omega
-
-theorem cpop_concat {x : BitVec w} {b : Bool} :
-    (x.concat b).cpop = b.toNat + x.cpop.setWidth (w + 1) := by
-  have := cpopNatRec_zero_le (x := x) (n := w)
-  have := Nat.lt_two_pow_self (n := w)
-  rw [cpop, cpop, cpopNatRec_concat_of_lt,
-    Nat.add_one_sub_one, natCast_eq_ofNat, ofNat_add]
-  congr
-  rw [setWidth_ofNat_of_le_of_lt (x := x.cpopNatRec w 0) (by omega) (by omega)]
-  omega
-
-@[simp]
-theorem toNat_cpop_concat {x : BitVec w} {b : Bool} :
-    (x.concat b).cpop.toNat = b.toNat + x.cpop.toNat := by
-  have := toNat_cpop_le (x := x)
-  have := Nat.lt_two_pow_self (n := w + 1)
-  simp only [cpop_concat, natCast_eq_ofNat, toNat_add, toNat_ofNat, toNat_setWidth, Nat.lt_add_one,
-    toNat_mod_cancel_of_lt, Nat.mod_add_mod]
-  rw [Nat.mod_eq_of_lt]
-  cases b <;> (simp; omega)
-
-theorem cpop_cons_eq_cpop_concat (x : BitVec w) :
-    (x.cons y).cpop = (x.concat y).cpop := by
-  rw [cpop_cons, cpop_concat]
-
-@[simp]
-theorem cpop_reverse (x : BitVec w) :
-    x.reverse.cpop = x.cpop := by
-  induction w
-  · case zero =>
-    simp [cpop, reverse]
-  · case succ w ihw =>
-    rw [← concat_reverse_setWidth_msb_eq_reverse, cpop_concat, ihw, ← cpop_cons]
-    simp
-
-@[simp]
-theorem cpopNatRec_cast_eq_of_eq {x : BitVec w} (p : w = v) :
-    (x.cast p).cpopNatRec n = x.cpopNatRec n := by
-  subst p; simp
-
-@[simp]
-theorem cpop_cast (x : BitVec w) (h : w = v) :
-    (x.cast h).cpop = x.cpop.cast h := by
-  simp [cpop, cpopNatRec_cast_eq_of_eq, h]
-
-@[simp]
-theorem toNat_cpop_append {x : BitVec w} {y : BitVec u} :
-    (x ++ y).cpop.toNat = x.cpop.toNat + y.cpop.toNat := by
-  induction w generalizing u
-  · case zero =>
-    simp [cpop]
-  · case succ w ihw =>
-    rw [← cons_msb_setWidth x, toNat_cpop_cons, cons_append, cpop_cast, toNat_cast,
-      toNat_cpop_cons, ihw, ← Nat.add_assoc]
-
-theorem cpop_append {x : BitVec w} {y : BitVec u} :
-    (x ++ y).cpop = x.cpop.setWidth (w + u) + y.cpop.setWidth (w + u) := by
-  apply eq_of_toNat_eq
-  have := toNat_cpop_le x
-  have := toNat_cpop_le y
-  have := Nat.lt_two_pow_self (n := w + u)
-  simp only [toNat_cpop_append, toNat_add, toNat_setWidth, Nat.add_mod_mod, Nat.mod_add_mod]
-  rw [Nat.mod_eq_of_lt (by omega)]
-
 end BitVec

src/Init/Data/Bool.lean

@@ -111,11 +111,35 @@ Needed for confluence of term `(a && b) ↔ a` which reduces to `(a && b) = a` v
 @[simp] theorem eq_self_and : ∀ {a b : Bool}, (a = (a && b)) ↔ (a → b) := by decide
 @[simp] theorem eq_and_self : ∀ {a b : Bool}, (b = (a && b)) ↔ (b → a) := by decide
 
+@[deprecated and_eq_left_iff_imp (since := "2025-04-04")]
+abbrev and_iff_left_iff_imp := @and_eq_left_iff_imp
+
+@[deprecated and_eq_right_iff_imp (since := "2025-04-04")]
+abbrev and_iff_right_iff_imp := @and_eq_right_iff_imp
+
+@[deprecated eq_self_and (since := "2025-04-04")]
+abbrev iff_self_and := @eq_self_and
+
+@[deprecated eq_and_self (since := "2025-04-04")]
+abbrev iff_and_self := @eq_and_self
+
 @[simp] theorem not_and_eq_left_iff_and  : ∀ {a b : Bool}, ((!a && b) = a) ↔ !a ∧ !b := by decide
 @[simp] theorem and_not_eq_right_iff_and : ∀ {a b : Bool}, ((a && !b) = b) ↔ !a ∧ !b := by decide
 @[simp] theorem eq_not_self_and : ∀ {a b : Bool}, (a = (!a && b)) ↔ !a ∧ !b := by decide
 @[simp] theorem eq_and_not_self : ∀ {a b : Bool}, (b = (a && !b)) ↔ !a ∧ !b := by decide
 
+@[deprecated not_and_eq_left_iff_and (since := "2025-04-04")]
+abbrev not_and_iff_left_iff_imp := @not_and_eq_left_iff_and
+
+@[deprecated and_not_eq_right_iff_and (since := "2025-04-04")]
+abbrev and_not_iff_right_iff_imp := @and_not_eq_right_iff_and
+
+@[deprecated eq_not_self_and (since := "2025-04-04")]
+abbrev iff_not_self_and := @eq_not_self_and
+
+@[deprecated eq_and_not_self (since := "2025-04-04")]
+abbrev iff_and_not_self := @eq_and_not_self
+
 /-! ### or -/
 
 @[simp] theorem or_self_left  : ∀ (a b : Bool), (a || (a || b)) = (a || b) := by decide
@@ -145,11 +169,35 @@ Needed for confluence of term `(a || b) ↔ a` which reduces to `(a || b) = a` v
 @[simp] theorem eq_self_or : ∀ {a b : Bool}, (a = (a || b)) ↔ (b → a) := by decide
 @[simp] theorem eq_or_self : ∀ {a b : Bool}, (b = (a || b)) ↔ (a → b) := by decide
 
+@[deprecated or_eq_left_iff_imp (since := "2025-04-04")]
+abbrev or_iff_left_iff_imp := @or_eq_left_iff_imp
+
+@[deprecated or_eq_right_iff_imp (since := "2025-04-04")]
+abbrev or_iff_right_iff_imp := @or_eq_right_iff_imp
+
+@[deprecated eq_self_or (since := "2025-04-04")]
+abbrev iff_self_or := @eq_self_or
+
+@[deprecated eq_or_self (since := "2025-04-04")]
+abbrev iff_or_self := @eq_or_self
+
 @[simp] theorem not_or_eq_left_iff_and  : ∀ {a b : Bool}, ((!a || b) = a) ↔ a ∧ b := by decide
 @[simp] theorem or_not_eq_right_iff_and : ∀ {a b : Bool}, ((a || !b) = b) ↔ a ∧ b := by decide
 @[simp] theorem eq_not_self_or : ∀ {a b : Bool}, (a = (!a || b)) ↔ a ∧ b := by decide
 @[simp] theorem eq_or_not_self : ∀ {a b : Bool}, (b = (a || !b)) ↔ a ∧ b := by decide
 
+@[deprecated not_or_eq_left_iff_and (since := "2025-04-04")]
+abbrev not_or_iff_left_iff_imp := @not_or_eq_left_iff_and
+
+@[deprecated or_not_eq_right_iff_and (since := "2025-04-04")]
+abbrev or_not_iff_right_iff_imp := @or_not_eq_right_iff_and
+
+@[deprecated eq_not_self_or (since := "2025-04-04")]
+abbrev iff_not_self_or := @eq_not_self_or
+
+@[deprecated eq_or_not_self (since := "2025-04-04")]
+abbrev iff_or_not_self := @eq_or_not_self
+
 theorem or_comm : ∀ (x y : Bool), (x || y) = (y || x) := by decide
 instance : Std.Commutative (· || ·) := ⟨or_comm⟩
 
@@ -260,7 +308,7 @@ instance : Std.Associative (· != ·) := ⟨bne_assoc⟩
 
 theorem eq_not_of_ne : ∀ {x y : Bool}, x ≠ y → x = !y := by decide
 
-/-! ### coercion related normal forms -/
+/-! ### coercision related normal forms -/
 
 theorem beq_eq_decide_eq [BEq α] [LawfulBEq α] [DecidableEq α] (a b : α) :
     (a == b) = decide (a = b) := by
@@ -514,7 +562,6 @@ theorem exists_bool {p : Bool → Prop} : (∃ b, p b) ↔ p false ∨ p true :=
 theorem cond_eq_ite {α} (b : Bool) (t e : α) : cond b t e = if b then t else e := by
   cases b <;> simp
 
-@[deprecated cond_eq_ite (since := "2025-10-29")]
 theorem cond_eq_if : (bif b then x else y) = (if b then x else y) := cond_eq_ite b x y
 
 @[simp] theorem cond_not (b : Bool) (t e : α) : cond (!b) t e = cond b e t := by
@@ -574,6 +621,11 @@ protected theorem cond_false {α : Sort u} {a b : α} : cond false a b = b := co
 @[simp] theorem cond_then_self  : ∀ (c b : Bool), cond c c b = (c || b) := by decide
 @[simp] theorem cond_else_self : ∀ (c b : Bool), cond c b c = (c && b) := by decide
 
+@[deprecated cond_then_not_self (since := "2025-04-04")] abbrev cond_true_not_same := @cond_then_not_self
+@[deprecated cond_else_not_self (since := "2025-04-04")] abbrev cond_false_not_same := @cond_else_not_self
+@[deprecated cond_then_self (since := "2025-04-04")] abbrev cond_true_same := @cond_then_self
+@[deprecated cond_else_self (since := "2025-04-04")] abbrev cond_false_same := @cond_else_self
+
 theorem cond_pos {b : Bool} {a a' : α} (h : b = true) : (bif b then a else a') = a := by
   rw [h, cond_true]
 
@@ -613,7 +665,7 @@ theorem decide_beq_decide (p q : Prop) [dpq : Decidable (p ↔ q)] [dp : Decidab
 
 end Bool
 
-export Bool (cond_eq_if cond_eq_ite xor and or not)
+export Bool (cond_eq_if xor and or not)
 
 /-! ### decide -/
 

src/Init/Data/ByteArray/Basic.lean

@@ -24,6 +24,9 @@ attribute [ext] ByteArray
 instance : DecidableEq ByteArray :=
   fun _ _ => decidable_of_decidable_of_iff ByteArray.ext_iff.symm
 
+@[deprecated emptyWithCapacity (since := "2025-03-12")]
+abbrev mkEmpty := emptyWithCapacity
+
 instance : Inhabited ByteArray where
   default := empty
 
@@ -132,11 +135,6 @@ Copies the bytes with indices {name}`b` (inclusive) to {name}`e` (exclusive) to
 def extract (a : ByteArray) (b e : Nat) : ByteArray :=
   a.copySlice b empty 0 (e - b)
 
-/--
-Appends two byte arrays using fast array primitives instead of converting them into lists and back.
-
-In compiled code, this function replaces calls to {name}`ByteArray.append`.
--/
 @[inline]
 protected def fastAppend (a : ByteArray) (b : ByteArray) : ByteArray :=
   -- we assume that `append`s may be repeated, so use asymptotic growing; use `copySlice` directly to customize
@@ -248,7 +246,7 @@ protected def forIn {β : Type v} {m : Type v → Type w} [Monad m] (as : ByteAr
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
 
-instance [Monad m] : ForIn m ByteArray UInt8 where
+instance : ForIn m ByteArray UInt8 where
   forIn := ByteArray.forIn
 
 /--
@@ -269,8 +267,6 @@ unsafe def foldlMUnsafe {β : Type v} {m : Type v → Type w} [Monad m] (f : β
   if start < stop then
     if stop ≤ as.size then
       fold (USize.ofNat start) (USize.ofNat stop) init
-    else if start < as.size then
-      fold (USize.ofNat start) (USize.ofNat as.size) init
     else
       pure init
   else

src/Init/Data/ByteArray/Lemmas.lean

@@ -10,8 +10,6 @@ public import Init.Data.ByteArray.Basic
 
 public section
 
-namespace ByteArray
-
 -- At present the preferred normal form for empty byte arrays is `ByteArray.empty`
 @[simp]
 theorem emptyc_eq_empty : (∅ : ByteArray) = ByteArray.empty := rfl
@@ -20,10 +18,10 @@ theorem emptyc_eq_empty : (∅ : ByteArray) = ByteArray.empty := rfl
 theorem emptyWithCapacity_eq_empty : ByteArray.emptyWithCapacity 0 = ByteArray.empty := rfl
 
 @[simp]
-theorem data_empty : ByteArray.empty.data = #[] := rfl
+theorem ByteArray.data_empty : ByteArray.empty.data = #[] := rfl
 
 @[simp]
-theorem data_extract {a : ByteArray} {b e : Nat} :
+theorem ByteArray.data_extract {a : ByteArray} {b e : Nat} :
     (a.extract b e).data = a.data.extract b e := by
   simp [extract, copySlice]
   by_cases b ≤ e
@@ -31,39 +29,39 @@ theorem data_extract {a : ByteArray} {b e : Nat} :
   · rw [Array.extract_eq_empty_of_le (by omega), Array.extract_eq_empty_of_le (by omega)]
 
 @[simp]
-theorem extract_zero_size {b : ByteArray} : b.extract 0 b.size = b := by
+theorem ByteArray.extract_zero_size {b : ByteArray} : b.extract 0 b.size = b := by
   ext1
   simp
 
 @[simp]
-theorem extract_same {b : ByteArray} {i : Nat} : b.extract i i = ByteArray.empty := by
+theorem ByteArray.extract_same {b : ByteArray} {i : Nat} : b.extract i i = ByteArray.empty := by
   ext1
   simp [Nat.min_le_left]
 
-theorem fastAppend_eq_copySlice {a b : ByteArray} :
+theorem ByteArray.fastAppend_eq_copySlice {a b : ByteArray} :
   a.fastAppend b = b.copySlice 0 a a.size b.size false := rfl
 
 @[simp]
-theorem _root_.List.toByteArray_append {l l' : List UInt8} :
+theorem List.toByteArray_append {l l' : List UInt8} :
     (l ++ l').toByteArray = l.toByteArray ++ l'.toByteArray := by
   simp [List.toByteArray_append']
 
 @[simp]
-theorem toList_data_append {l l' : ByteArray} :
+theorem ByteArray.toList_data_append {l l' : ByteArray} :
     (l ++ l').data.toList = l.data.toList ++ l'.data.toList := by
   simp [← append_eq]
 
 @[simp]
-theorem data_append {l l' : ByteArray} :
+theorem ByteArray.data_append {l l' : ByteArray} :
     (l ++ l').data = l.data ++ l'.data := by
   simp [← Array.toList_inj]
 
 @[simp]
-theorem size_empty : ByteArray.empty.size = 0 := by
+theorem ByteArray.size_empty : ByteArray.empty.size = 0 := by
   simp [← ByteArray.size_data]
 
 @[simp]
-theorem _root_.List.data_toByteArray {l : List UInt8} :
+theorem List.data_toByteArray {l : List UInt8} :
     l.toByteArray.data = l.toArray := by
   rw [List.toByteArray]
   suffices ∀ a b, (List.toByteArray.loop a b).data = b.data ++ a.toArray by
@@ -72,159 +70,153 @@ theorem _root_.List.data_toByteArray {l : List UInt8} :
   fun_induction List.toByteArray.loop a b with simp_all
 
 @[simp]
-theorem _root_.List.size_toByteArray {l : List UInt8} :
+theorem List.size_toByteArray {l : List UInt8} :
     l.toByteArray.size = l.length := by
   simp [← ByteArray.size_data]
 
 @[simp]
-theorem _root_.List.toByteArray_nil : List.toByteArray [] = ByteArray.empty := rfl
+theorem List.toByteArray_nil : List.toByteArray [] = ByteArray.empty := rfl
 
 @[simp]
-theorem empty_append {b : ByteArray} : ByteArray.empty ++ b = b := by
+theorem ByteArray.empty_append {b : ByteArray} : ByteArray.empty ++ b = b := by
   ext1
   simp
 
 @[simp]
-theorem append_empty {b : ByteArray} : b ++ ByteArray.empty = b := by
+theorem ByteArray.append_empty {b : ByteArray} : b ++ ByteArray.empty = b := by
   ext1
   simp
 
 @[simp, grind =]
-theorem size_append {a b : ByteArray} : (a ++ b).size = a.size + b.size := by
+theorem ByteArray.size_append {a b : ByteArray} : (a ++ b).size = a.size + b.size := by
   simp [← size_data]
 
 @[simp]
-theorem size_eq_zero_iff {a : ByteArray} : a.size = 0 ↔ a = ByteArray.empty := by
+theorem ByteArray.size_eq_zero_iff {a : ByteArray} : a.size = 0 ↔ a = ByteArray.empty := by
   refine ⟨fun h => ?_, fun h => h ▸ ByteArray.size_empty⟩
   ext1
   simp [← Array.size_eq_zero_iff, h]
 
-theorem getElem_eq_getElem_data {a : ByteArray} {i : Nat} {h : i < a.size} :
+theorem ByteArray.getElem_eq_getElem_data {a : ByteArray} {i : Nat} {h : i < a.size} :
     a[i] = a.data[i]'(by simpa [← size_data]) := rfl
 
 @[simp]
-theorem getElem_append_left {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size}
+theorem ByteArray.getElem_append_left {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size}
     (hlt : i < a.size) : (a ++ b)[i] = a[i] := by
   simp only [getElem_eq_getElem_data, data_append]
   rw [Array.getElem_append_left (by simpa)]
 
-theorem getElem_append_right {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size}
+theorem ByteArray.getElem_append_right {i : Nat} {a b : ByteArray} {h : i < (a ++ b).size}
     (hle : a.size ≤ i) : (a ++ b)[i] = b[i - a.size]'(by simp_all; omega) := by
   simp only [getElem_eq_getElem_data, data_append]
   rw [Array.getElem_append_right (by simpa)]
   simp
 
 @[simp]
-theorem _root_.List.getElem_toByteArray {l : List UInt8} {i : Nat} {h : i < l.toByteArray.size} :
+theorem List.getElem_toByteArray {l : List UInt8} {i : Nat} {h : i < l.toByteArray.size} :
     l.toByteArray[i]'h = l[i]'(by simp_all) := by
   simp [ByteArray.getElem_eq_getElem_data]
 
-theorem _root_.List.getElem_eq_getElem_toByteArray {l : List UInt8} {i : Nat} {h : i < l.length} :
+theorem List.getElem_eq_getElem_toByteArray {l : List UInt8} {i : Nat} {h : i < l.length} :
     l[i]'h = l.toByteArray[i]'(by simp_all) := by
   simp
 
 @[simp]
-theorem size_extract {a : ByteArray} {b e : Nat} :
+theorem ByteArray.size_extract {a : ByteArray} {b e : Nat} :
     (a.extract b e).size = min e a.size - b := by
   simp [← size_data]
 
 @[simp]
-theorem extract_eq_empty_iff {b : ByteArray} {i j : Nat} : b.extract i j = ByteArray.empty ↔ min j b.size ≤ i := by
+theorem ByteArray.extract_eq_empty_iff {b : ByteArray} {i j : Nat} : b.extract i j = ByteArray.empty ↔ min j b.size ≤ i := by
   rw [← size_eq_zero_iff, size_extract]
   omega
 
 @[simp]
-theorem extract_add_left {b : ByteArray} {i j : Nat} : b.extract (i + j) i = ByteArray.empty := by
+theorem ByteArray.extract_add_left {b : ByteArray} {i j : Nat} : b.extract (i + j) i = ByteArray.empty := by
   simp only [extract_eq_empty_iff]
   exact Nat.le_trans (Nat.min_le_left _ _) (by simp)
 
 @[simp]
-theorem append_eq_empty_iff {a b : ByteArray} :
+theorem ByteArray.append_eq_empty_iff {a b : ByteArray} :
     a ++ b = ByteArray.empty ↔ a = ByteArray.empty ∧ b = ByteArray.empty := by
   simp [← size_eq_zero_iff, size_append]
 
 @[simp]
-theorem toByteArray_eq_empty {l : List UInt8} :
+theorem List.toByteArray_eq_empty {l : List UInt8} :
     l.toByteArray = ByteArray.empty ↔ l = [] := by
   simp [← ByteArray.size_eq_zero_iff]
 
-@[simp]
-theorem append_right_inj {ys₁ ys₂ : ByteArray} (xs : ByteArray) :
+theorem ByteArray.append_right_inj {ys₁ ys₂ : ByteArray} (xs : ByteArray) :
     xs ++ ys₁ = xs ++ ys₂ ↔ ys₁ = ys₂ := by
   simp [ByteArray.ext_iff, Array.append_right_inj]
 
 @[simp]
-theorem append_left_inj {xs₁ xs₂ : ByteArray} (ys : ByteArray) :
-    xs₁ ++ ys = xs₂ ++ ys ↔ xs₁ = xs₂ := by
-  simp [ByteArray.ext_iff, Array.append_left_inj]
-
-@[simp]
-theorem extract_append_extract {a : ByteArray} {i j k : Nat} :
+theorem ByteArray.extract_append_extract {a : ByteArray} {i j k : Nat} :
     a.extract i j ++ a.extract j k = a.extract (min i j) (max j k) := by
   ext1
   simp
 
-theorem extract_eq_extract_append_extract {a : ByteArray} {i k : Nat} (j : Nat)
+theorem ByteArray.extract_eq_extract_append_extract {a : ByteArray} {i k : Nat} (j : Nat)
     (hi : i ≤ j) (hk : j ≤ k) :
     a.extract i k = a.extract i j ++ a.extract j k := by
   simp
   rw [Nat.min_eq_left hi, Nat.max_eq_right hk]
 
-theorem append_inj_left {xs₁ xs₂ ys₁ ys₂ : ByteArray} (h : xs₁ ++ ys₁ = xs₂ ++ ys₂) (hl : xs₁.size = xs₂.size) : xs₁ = xs₂ := by
+theorem ByteArray.append_inj_left {xs₁ xs₂ ys₁ ys₂ : ByteArray} (h : xs₁ ++ ys₁ = xs₂ ++ ys₂) (hl : xs₁.size = xs₂.size) : xs₁ = xs₂ := by
   simp only [ByteArray.ext_iff, ← ByteArray.size_data, ByteArray.data_append] at *
   exact Array.append_inj_left h hl
 
-theorem extract_append_eq_right {a b : ByteArray} {i j : Nat} (hi : i = a.size) (hj : j = a.size + b.size) :
+theorem ByteArray.extract_append_eq_right {a b : ByteArray} {i j : Nat} (hi : i = a.size) (hj : j = a.size + b.size) :
     (a ++ b).extract i j = b := by
   subst hi hj
   ext1
   simp [← size_data]
 
-theorem extract_append_eq_left {a b : ByteArray} {i : Nat} (hi : i = a.size) :
+theorem ByteArray.extract_append_eq_left {a b : ByteArray} {i : Nat} (hi : i = a.size) :
     (a ++ b).extract 0 i = a := by
   subst hi
   ext1
   simp
 
-theorem extract_append_size_left {a b : ByteArray} {i : Nat} :
+theorem ByteArray.extract_append_size_left {a b : ByteArray} {i : Nat} :
     (a ++ b).extract i a.size = a.extract i a.size := by
   ext1
   simp
 
-theorem extract_append_size_add {a b : ByteArray} {i j : Nat} :
+theorem ByteArray.extract_append_size_add {a b : ByteArray} {i j : Nat} :
     (a ++ b).extract (a.size + i) (a.size + j) = b.extract i j := by
   ext1
   simp
 
-theorem extract_append  {as bs : ByteArray} {i j : Nat} :
+theorem ByteArray.extract_append  {as bs : ByteArray} {i j : Nat} :
     (as ++ bs).extract i j = as.extract i j ++ bs.extract (i - as.size) (j - as.size) := by
   ext1
   simp
 
-theorem extract_append_size_add' {a b : ByteArray} {i j k : Nat} (h : k = a.size) :
+theorem ByteArray.extract_append_size_add' {a b : ByteArray} {i j k : Nat} (h : k = a.size) :
     (a ++ b).extract (k + i) (k + j) = b.extract i j := by
   cases h
   rw [extract_append_size_add]
 
-theorem extract_extract {a : ByteArray} {i j k l : Nat} :
+theorem ByteArray.extract_extract {a : ByteArray} {i j k l : Nat} :
     (a.extract i j).extract k l = a.extract (i + k) (min (i + l) j) := by
   ext1
   simp
 
-theorem getElem_extract_aux {xs : ByteArray} {start stop : Nat} (h : i < (xs.extract start stop).size) :
+theorem ByteArray.getElem_extract_aux {xs : ByteArray} {start stop : Nat} (h : i < (xs.extract start stop).size) :
     start + i < xs.size := by
   rw [size_extract] at h; apply Nat.add_lt_of_lt_sub'; apply Nat.lt_of_lt_of_le h
   apply Nat.sub_le_sub_right; apply Nat.min_le_right
 
-theorem getElem_extract {i : Nat} {b : ByteArray} {start stop : Nat}
+theorem ByteArray.getElem_extract {i : Nat} {b : ByteArray} {start stop : Nat}
     (h) : (b.extract start stop)[i]'h = b[start + i]'(getElem_extract_aux h) := by
   simp [getElem_eq_getElem_data]
 
-theorem extract_eq_extract_left {a : ByteArray} {i i' j : Nat} :
+theorem ByteArray.extract_eq_extract_left {a : ByteArray} {i i' j : Nat} :
     a.extract i j = a.extract i' j ↔ min j a.size - i = min j a.size - i' := by
   simp [ByteArray.ext_iff, Array.extract_eq_extract_left]
 
-theorem extract_add_one {a : ByteArray} {i : Nat} (ha : i + 1 ≤ a.size) :
+theorem ByteArray.extract_add_one {a : ByteArray} {i : Nat} (ha : i + 1 ≤ a.size) :
     a.extract i (i + 1) = [a[i]].toByteArray := by
   ext
   · simp
@@ -233,57 +225,50 @@ theorem extract_add_one {a : ByteArray} {i : Nat} (ha : i + 1 ≤ a.size) :
     obtain rfl : j = 0 := by simpa using hj'
     simp [ByteArray.getElem_eq_getElem_data]
 
-theorem extract_add_two {a : ByteArray} {i : Nat} (ha : i + 2 ≤ a.size) :
+theorem ByteArray.extract_add_two {a : ByteArray} {i : Nat} (ha : i + 2 ≤ a.size) :
     a.extract i (i + 2) = [a[i], a[i + 1]].toByteArray := by
   rw [extract_eq_extract_append_extract (i + 1) (by simp) (by omega),
     extract_add_one (by omega), extract_add_one (by omega)]
   simp [← List.toByteArray_append]
 
-theorem extract_add_three {a : ByteArray} {i : Nat} (ha : i + 3 ≤ a.size) :
+theorem ByteArray.extract_add_three {a : ByteArray} {i : Nat} (ha : i + 3 ≤ a.size) :
     a.extract i (i + 3) = [a[i], a[i + 1], a[i + 2]].toByteArray := by
   rw [extract_eq_extract_append_extract (i + 1) (by simp) (by omega),
     extract_add_one (by omega), extract_add_two (by omega)]
   simp [← List.toByteArray_append]
 
-theorem extract_add_four {a : ByteArray} {i : Nat} (ha : i + 4 ≤ a.size) :
+theorem ByteArray.extract_add_four {a : ByteArray} {i : Nat} (ha : i + 4 ≤ a.size) :
     a.extract i (i + 4) = [a[i], a[i + 1], a[i + 2], a[i + 3]].toByteArray := by
   rw [extract_eq_extract_append_extract (i + 1) (by simp) (by omega),
     extract_add_one (by omega), extract_add_three (by omega)]
   simp [← List.toByteArray_append]
 
-theorem append_assoc {a b c : ByteArray} : a ++ b ++ c = a ++ (b ++ c) := by
+theorem ByteArray.append_assoc {a b c : ByteArray} : a ++ b ++ c = a ++ (b ++ c) := by
   ext1
   simp
 
 @[simp]
-theorem toList_empty : ByteArray.empty.toList = [] := by
+theorem ByteArray.toList_empty : ByteArray.empty.toList = [] := by
   simp [ByteArray.toList, ByteArray.toList.loop]
 
-theorem copySlice_eq_append {src : ByteArray} {srcOff : Nat} {dest : ByteArray} {destOff len : Nat} {exact : Bool} :
+theorem ByteArray.copySlice_eq_append {src : ByteArray} {srcOff : Nat} {dest : ByteArray} {destOff len : Nat} {exact : Bool} :
     ByteArray.copySlice src srcOff dest destOff len exact =
       dest.extract 0 destOff ++ src.extract srcOff (srcOff +len) ++ dest.extract (destOff + min len (src.data.size - srcOff)) dest.data.size := by
   ext1
   simp [copySlice]
 
 @[simp]
-theorem data_set {as : ByteArray} {i : Nat} {h : i < as.size} {a : UInt8} :
+theorem ByteArray.data_set {as : ByteArray} {i : Nat} {h : i < as.size} {a : UInt8} :
     (as.set i a h).data = as.data.set i a (by simpa) := by
   simp [set]
 
-theorem set_eq_push_extract_append_extract {as : ByteArray} {i : Nat} (h : i < as.size) {a : UInt8} :
+theorem ByteArray.set_eq_push_extract_append_extract {as : ByteArray} {i : Nat} (h : i < as.size) {a : UInt8} :
     as.set i a h = (as.extract 0 i).push a ++ as.extract (i + 1) as.size := by
   ext1
   simpa using Array.set_eq_push_extract_append_extract _
 
 @[simp]
-theorem append_toByteArray_singleton {as : ByteArray} {a : UInt8} :
+theorem ByteArray.append_toByteArray_singleton {as : ByteArray} {a : UInt8} :
     as ++ [a].toByteArray = as.push a := by
   ext1
   simp
-
-@[simp]
-theorem extract_zero_max_size {a : ByteArray} {i : Nat} : a.extract 0 (max i a.size) = a := by
-  ext1
-  simp [Nat.le_max_right]
-
-end ByteArray

src/Init/Data/Char/Basic.lean

@@ -102,7 +102,7 @@ Returns `true` if the character is a uppercase ASCII letter.
 The uppercase ASCII letters are the following: `ABCDEFGHIJKLMNOPQRSTUVWXYZ`.
 -/
 @[inline] def isUpper (c : Char) : Bool :=
-  c.val ≥ 'A'.val ∧ c.val ≤ 'Z'.val
+  c.val ≥ 65 && c.val ≤ 90
 
 /--
 Returns `true` if the character is a lowercase ASCII letter.
@@ -110,7 +110,7 @@ Returns `true` if the character is a lowercase ASCII letter.
 The lowercase ASCII letters are the following: `abcdefghijklmnopqrstuvwxyz`.
 -/
 @[inline] def isLower (c : Char) : Bool :=
-  c.val ≥ 'a'.val && c.val ≤ 'z'.val
+  c.val ≥ 97 && c.val ≤ 122
 
 /--
 Returns `true` if the character is an ASCII letter.
@@ -126,7 +126,7 @@ Returns `true` if the character is an ASCII digit.
 The ASCII digits are the following: `0123456789`.
 -/
 @[inline] def isDigit (c : Char) : Bool :=
-  c.val ≥ '0'.val && c.val ≤ '9'.val
+  c.val ≥ 48 && c.val ≤ 57
 
 /--
 Returns `true` if the character is an ASCII letter or digit.
@@ -143,16 +143,9 @@ alphabet are returned unchanged.
 
 The uppercase ASCII letters are the following: `ABCDEFGHIJKLMNOPQRSTUVWXYZ`.
 -/
-@[inline]
 def toLower (c : Char) : Char :=
-  if h : c.val ≥ 'A'.val ∧ c.val ≤ 'Z'.val then
-    ⟨c.val + ('a'.val - 'A'.val), ?_⟩
-  else
-    c
-where finally
-  have h : c.val.toBitVec.toNat + ('a'.val - 'A'.val).toBitVec.toNat < 0xd800 :=
-    Nat.add_lt_add_right (Nat.lt_of_le_of_lt h.2 (by decide)) _
-  exact .inl (lt_of_eq_of_lt (Nat.mod_eq_of_lt (Nat.lt_trans h (by decide))) h)
+  let n := toNat c;
+  if n >= 65 ∧ n <= 90 then ofNat (n + 32) else c
 
 /--
 Converts a lowercase ASCII letter to the corresponding uppercase letter. Letters outside the ASCII
@@ -160,20 +153,8 @@ alphabet are returned unchanged.
 
 The lowercase ASCII letters are the following: `abcdefghijklmnopqrstuvwxyz`.
 -/
-@[inline]
 def toUpper (c : Char) : Char :=
-  if h : c.val ≥ 'a'.val ∧ c.val ≤ 'z'.val then
-    ⟨c.val + ('A'.val - 'a'.val), ?_⟩
-  else
-    c
-where finally
-  have h₁ : 2^32 ≤ c.val.toNat + ('A'.val - 'a'.val).toNat :=
-    @Nat.add_le_add 'a'.val.toNat _ (2^32 - 'a'.val.toNat) _ h.1 (by decide)
-  have h₂ : c.val.toBitVec.toNat + ('A'.val - 'a'.val).toNat < 2^32 + 0xd800 :=
-    Nat.add_lt_add_right (Nat.lt_of_le_of_lt h.2 (by decide)) _
-  have add_eq {x y : UInt32} : (x + y).toNat = (x.toNat + y.toNat) % 2^32 := rfl
-  replace h₂ := Nat.sub_lt_left_of_lt_add h₁ h₂
-  exact .inl <| lt_of_eq_of_lt (add_eq.trans (Nat.mod_eq_sub_mod h₁) |>.trans
-    (Nat.mod_eq_of_lt (Nat.lt_trans h₂ (by decide)))) h₂
+  let n := toNat c;
+  if n >= 97 ∧ n <= 122 then ofNat (n - 32) else c
 
 end Char

src/Init/Data/Char/Lemmas.lean

@@ -13,16 +13,12 @@ public section
 
 namespace Char
 
-@[deprecated Char.ext (since := "2025-10-26")]
-protected theorem eq_of_val_eq : {a b : Char} → a.val = b.val → a = b
+@[ext] protected theorem ext : {a b : Char} → a.val = b.val → a = b
   | ⟨_,_⟩, ⟨_,_⟩, rfl => rfl
 
 theorem le_def {a b : Char} : a ≤ b ↔ a.1 ≤ b.1 := .rfl
 theorem lt_def {a b : Char} : a < b ↔ a.1 < b.1 := .rfl
-
-@[deprecated lt_def (since := "2025-10-26")]
 theorem lt_iff_val_lt_val {a b : Char} : a < b ↔ a.val < b.val := Iff.rfl
-
 @[simp] protected theorem not_le {a b : Char} : ¬ a ≤ b ↔ b < a := UInt32.not_le
 @[simp] protected theorem not_lt {a b : Char} : ¬ a < b ↔ b ≤ a := UInt32.not_lt
 @[simp] protected theorem le_refl (a : Char) : a ≤ a := by simp [le_def]
@@ -55,12 +51,8 @@ instance leAntisymm : Std.Antisymm (· ≤ · : Char → Char → Prop) where
   antisymm _ _ := Char.le_antisymm
 
 -- This instance is useful while setting up instances for `String`.
-instance ltTrichotomous : Std.Trichotomous (· < · : Char → Char → Prop) where
-  trichotomous _ _ h₁ h₂ := Char.le_antisymm (by simpa using h₂) (by simpa using h₁)
-
-@[deprecated ltTrichotomous (since := "2025-10-27")]
 def notLTAntisymm : Std.Antisymm (¬ · < · : Char → Char → Prop) where
-  antisymm := Char.ltTrichotomous.trichotomous
+  antisymm _ _ h₁ h₂ := Char.le_antisymm (by simpa using h₂) (by simpa using h₁)
 
 instance ltAsymm : Std.Asymm (· < · : Char → Char → Prop) where
   asymm _ _ := Char.lt_asymm
@@ -77,9 +69,4 @@ def notLTTotal : Std.Total (¬ · < · : Char → Char → Prop) where
   rw [Char.ofNat, dif_pos]
   rfl
 
-@[simp]
-theorem toUInt8_val {c : Char} : c.val.toUInt8 = c.toUInt8 := rfl
-
-theorem toString_eq_singleton {c : Char} : c.toString = String.singleton c := rfl
-
 end Char

src/Init/Data/Dyadic/Basic.lean

@@ -287,7 +287,7 @@ theorem toRat_add (x y : Dyadic) : toRat (x + y) = toRat x + toRat y := by
     · rename_i h
       cases Int.sub_eq_iff_eq_add.mp h
       rw [toRat_ofOdd_eq_mkRat, Rat.mkRat_eq_iff (NeZero.ne _) (NeZero.ne _)]
-      simp only [succ_eq_add_one, Int.ofNat_eq_natCast, Int.add_shiftLeft, ← Int.shiftLeft_add,
+      simp only [succ_eq_add_one, Int.ofNat_eq_coe, Int.add_shiftLeft, ← Int.shiftLeft_add,
         Int.natCast_mul, Int.natCast_shiftLeft, Int.shiftLeft_mul_shiftLeft, Int.add_mul]
       congr 2 <;> omega
     · rename_i h
@@ -438,13 +438,13 @@ theorem toDyadic_mkRat (a : Int) (b : Nat) (prec : Int) :
   rcases h : mkRat a b with ⟨n, d, hnz, hr⟩
   obtain ⟨m, hm, rfl, rfl⟩ := Rat.mkRat_num_den hb h
   cases prec
-  · simp only [Rat.toDyadic, Int.ofNat_eq_natCast, Int.toNat_natCast, Int.toNat_neg_natCast,
+  · simp only [Rat.toDyadic, Int.ofNat_eq_coe, Int.toNat_natCast, Int.toNat_neg_natCast,
       shiftLeft_zero, Int.natCast_mul]
-    rw [Int.mul_comm d, ← Int.ediv_ediv_of_nonneg (by simp), ← Int.shiftLeft_mul,
+    rw [Int.mul_comm d, ← Int.ediv_ediv (by simp), ← Int.shiftLeft_mul,
       Int.mul_ediv_cancel _ (by simpa using hm)]
   · simp only [Rat.toDyadic, Int.natCast_shiftLeft, Int.negSucc_eq, ← Int.natCast_add_one,
       Int.toNat_neg_natCast, Int.shiftLeft_zero, Int.neg_neg, Int.toNat_natCast, Int.natCast_mul]
-    rw [Int.mul_comm d, ← Int.mul_shiftLeft, ← Int.ediv_ediv_of_nonneg (by simp),
+    rw [Int.mul_comm d, ← Int.mul_shiftLeft, ← Int.ediv_ediv (by simp),
       Int.mul_ediv_cancel _ (by simpa using hm)]
 
 theorem toDyadic_eq_ofIntWithPrec (x : Rat) (prec : Int) :
@@ -463,7 +463,7 @@ theorem toRat_toDyadic (x : Rat) (prec : Int) :
   rw [Rat.floor_def, Int.shiftLeft_eq, Nat.shiftLeft_eq]
   match prec with
   | .ofNat prec =>
-    simp only [Int.ofNat_eq_natCast, Int.toNat_natCast, Int.toNat_neg_natCast, Nat.pow_zero,
+    simp only [Int.ofNat_eq_coe, Int.toNat_natCast, Int.toNat_neg_natCast, Nat.pow_zero,
       Nat.mul_one]
     have : (2 ^ prec : Rat) = ((2 ^ prec : Nat) : Rat) := by simp
     rw [Rat.zpow_natCast, this, Rat.mul_def']
@@ -472,7 +472,7 @@ theorem toRat_toDyadic (x : Rat) (prec : Int) :
       Rat.den_ofNat, Nat.one_pow, Nat.mul_one]
     split
     · simp_all
-    · rw [Int.ediv_ediv_of_nonneg (Int.natCast_nonneg _)]
+    · rw [Int.ediv_ediv (Int.ofNat_zero_le _)]
       congr 1
       rw [Int.natCast_ediv, Int.mul_ediv_cancel']
       rw [Int.natCast_dvd_natCast]
@@ -495,7 +495,7 @@ theorem toRat_toDyadic (x : Rat) (prec : Int) :
     simp only [this, Int.mul_one]
     split
     · simp_all
-    · rw [Int.ediv_ediv_of_nonneg (Int.natCast_nonneg _)]
+    · rw [Int.ediv_ediv (Int.ofNat_zero_le _)]
       congr 1
       rw [Int.natCast_ediv, Int.mul_ediv_cancel']
       · simp
@@ -682,11 +682,9 @@ instance : LE Dyadic where
 instance : DecidableLT Dyadic := fun _ _ => inferInstanceAs (Decidable (_ = true))
 instance : DecidableLE Dyadic := fun _ _ => inferInstanceAs (Decidable (_ = true))
 
-@[simp]
-theorem toRat_lt_toRat_iff {x y : Dyadic} : x.toRat < y.toRat ↔ x < y := blt_iff_toRat.symm
+theorem lt_iff_toRat {x y : Dyadic} : x < y ↔ x.toRat < y.toRat := blt_iff_toRat
 
-@[simp]
-theorem toRat_le_toRat_iff {x y : Dyadic} : x.toRat ≤ y.toRat ↔ x ≤ y := ble_iff_toRat.symm
+theorem le_iff_toRat {x y : Dyadic} : x ≤ y ↔ x.toRat ≤ y.toRat := ble_iff_toRat
 
 @[simp]
 protected theorem not_le {x y : Dyadic} : ¬x < y ↔ y ≤ x := by
@@ -698,20 +696,20 @@ protected theorem not_lt {x y : Dyadic} : ¬x ≤ y ↔ y < x := by
 
 @[simp]
 protected theorem le_refl (x : Dyadic) : x ≤ x := by
-  rw [← toRat_le_toRat_iff]
+  rw [le_iff_toRat]
   exact Rat.le_refl
 
 protected theorem le_trans {x y z : Dyadic} (h : x ≤ y) (h' : y ≤ z) : x ≤ z := by
-  rw [← toRat_le_toRat_iff] at h h' ⊢
+  rw [le_iff_toRat] at h h' ⊢
   exact Rat.le_trans h h'
 
 protected theorem le_antisymm {x y : Dyadic} (h : x ≤ y) (h' : y ≤ x) : x = y := by
-  rw [← toRat_le_toRat_iff] at h h'
+  rw [le_iff_toRat] at h h'
   rw [← toRat_inj]
   exact Rat.le_antisymm h h'
 
 protected theorem le_total (x y : Dyadic) : x ≤ y ∨ y ≤ x := by
-  rw [← toRat_le_toRat_iff, ← toRat_le_toRat_iff]
+  rw [le_iff_toRat, le_iff_toRat]
   exact Rat.le_total
 
 instance : Std.LawfulOrderLT Dyadic where

src/Init/Data/Dyadic/Instances.lean

@@ -52,8 +52,8 @@ instance : NoNatZeroDivisors Dyadic where
 
 instance : OrderedRing Dyadic where
   zero_lt_one := by decide
-  add_le_left_iff _ := by simp [← toRat_le_toRat_iff, Rat.add_le_add_right]
-  mul_lt_mul_of_pos_left {_ _ _} := by simpa [← toRat_lt_toRat_iff] using Rat.mul_lt_mul_of_pos_left
-  mul_lt_mul_of_pos_right {_ _ _} := by simpa [← toRat_lt_toRat_iff] using Rat.mul_lt_mul_of_pos_right
+  add_le_left_iff _ := by simp [le_iff_toRat, Rat.add_le_add_right]
+  mul_lt_mul_of_pos_left {_ _ _} := by simpa [lt_iff_toRat] using Rat.mul_lt_mul_of_pos_left
+  mul_lt_mul_of_pos_right {_ _ _} := by simpa [lt_iff_toRat] using Rat.mul_lt_mul_of_pos_right
 
 end Dyadic

src/Init/Data/Dyadic/Inv.lean

@@ -27,7 +27,7 @@ def invAtPrec (x : Dyadic) (prec : Int) : Dyadic :=
 /-- For a positive dyadic `x`, `invAtPrec x prec * x ≤ 1`. -/
 theorem invAtPrec_mul_le_one {x : Dyadic} (hx : 0 < x) (prec : Int) :
     invAtPrec x prec * x ≤ 1 := by
-  rw [← toRat_le_toRat_iff]
+  rw [le_iff_toRat]
   rw [toRat_mul]
   rw [show (1 : Dyadic).toRat = (1 : Rat) from rfl]
   unfold invAtPrec
@@ -39,19 +39,19 @@ theorem invAtPrec_mul_le_one {x : Dyadic} (hx : 0 < x) (prec : Int) :
     simp only
     have h_le : ((ofOdd n k hn).toRat.inv.toDyadic prec).toRat ≤ (ofOdd n k hn).toRat.inv := Rat.toRat_toDyadic_le
     have h_pos : 0 ≤ (ofOdd n k hn).toRat := by
-      rw [← toRat_lt_toRat_iff, toRat_zero] at hx
+      rw [lt_iff_toRat, toRat_zero] at hx
       exact Rat.le_of_lt hx
     calc ((ofOdd n k hn).toRat.inv.toDyadic prec).toRat * (ofOdd n k hn).toRat
         ≤ (ofOdd n k hn).toRat.inv * (ofOdd n k hn).toRat := Rat.mul_le_mul_of_nonneg_right h_le h_pos
       _ = 1 := by
         apply Rat.inv_mul_cancel
-        rw [← toRat_lt_toRat_iff, toRat_zero] at hx
+        rw [lt_iff_toRat, toRat_zero] at hx
         exact Rat.ne_of_gt hx
 
 /-- For a positive dyadic `x`, `1 < (invAtPrec x prec + 2^(-prec)) * x`. -/
 theorem one_lt_invAtPrec_add_inc_mul {x : Dyadic} (hx : 0 < x) (prec : Int) :
     1 < (invAtPrec x prec + ofIntWithPrec 1 prec) * x := by
-  rw [← toRat_lt_toRat_iff]
+  rw [lt_iff_toRat]
   rw [toRat_mul]
   rw [show (1 : Dyadic).toRat = (1 : Rat) from rfl]
   unfold invAtPrec
@@ -64,12 +64,12 @@ theorem one_lt_invAtPrec_add_inc_mul {x : Dyadic} (hx : 0 < x) (prec : Int) :
     have h_le : (ofOdd n k hn).toRat.inv < ((ofOdd n k hn).toRat.inv.toDyadic prec + ofIntWithPrec 1 prec).toRat :=
       Rat.lt_toRat_toDyadic_add
     have h_pos : 0 < (ofOdd n k hn).toRat := by
-      rwa [← toRat_lt_toRat_iff, toRat_zero] at hx
+      rwa [lt_iff_toRat, toRat_zero] at hx
     calc
       1 = (ofOdd n k hn).toRat.inv * (ofOdd n k hn).toRat := by
         symm
         apply Rat.inv_mul_cancel
-        rw [← toRat_lt_toRat_iff, toRat_zero] at hx
+        rw [lt_iff_toRat, toRat_zero] at hx
         exact Rat.ne_of_gt hx
       _ < ((ofOdd n k hn).toRat.inv.toDyadic prec + ofIntWithPrec 1 prec).toRat * (ofOdd n k hn).toRat :=
            Rat.mul_lt_mul_of_pos_right h_le h_pos

src/Init/Data/Dyadic/Round.lean

@@ -28,7 +28,7 @@ theorem roundDown_le {x : Dyadic} {prec : Int} : roundDown x prec ≤ x :=
     match h : k - prec with
     | .ofNat l =>
       dsimp
-      rw [ofOdd_eq_ofIntWithPrec, ← toRat_le_toRat_iff]
+      rw [ofOdd_eq_ofIntWithPrec, le_iff_toRat]
       replace h : k = Int.ofNat l + prec := by omega
       subst h
       simp only [toRat_ofIntWithPrec_eq_mul_two_pow]
@@ -36,7 +36,7 @@ theorem roundDown_le {x : Dyadic} {prec : Int} : roundDown x prec ≤ x :=
       refine Lean.Grind.OrderedRing.mul_le_mul_of_nonneg_right ?_ (Rat.zpow_nonneg (by decide))
       rw [Int.shiftRight_eq_div_pow]
       rw [← Lean.Grind.Field.IsOrdered.mul_le_mul_iff_of_pos_right (c := 2^(Int.ofNat l)) (Rat.zpow_pos (by decide))]
-      simp only [Int.natCast_pow, Int.cast_ofNat_Int, Int.ofNat_eq_natCast]
+      simp only [Int.natCast_pow, Int.cast_ofNat_Int, Int.ofNat_eq_coe]
       rw [Rat.mul_assoc, ← Rat.zpow_add (by decide), Int.add_left_neg, Rat.zpow_zero, Rat.mul_one]
       have : (2 : Rat) ^ (l : Int) = (2 ^ l : Int) := by
         rw [Rat.zpow_natCast, Rat.intCast_pow, Rat.intCast_ofNat]