fix: replace_fn.cpp

.github/ISSUE_TEMPLATE/bug_report.md

@@ -25,7 +25,7 @@ Please put an X between the brackets as you perform the following steps:
 
 ### Context
 
-[Broader context that the issue occurred in. If there was any prior discussion on [the Lean Zulip](https://leanprover.zulipchat.com), link it here as well.]
+[Broader context that the issue occured in. If there was any prior discussion on [the Lean Zulip](https://leanprover.zulipchat.com), link it here as well.]
 
 ### Steps to Reproduce
 
@@ -39,7 +39,7 @@ Please put an X between the brackets as you perform the following steps:
 
 ### Versions
 
-[Output of `#version` or `#eval Lean.versionString`]
+[Output of `#eval Lean.versionString`]
 [OS version, if not using live.lean-lang.org.]
 
 ### Additional Information

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,17 +5,10 @@
 * Include the link to your `RFC` or `bug` issue in the description.
 * If the issue does not already have approval from a developer, submit the PR as draft.
 * The PR title/description will become the commit message. Keep it up-to-date as the PR evolves.
-* For `feat/fix` PRs, the first paragraph starting with "This PR" must be present and will become a
-  changelog entry unless the PR is labeled with `no-changelog`. If the PR does not have this label,
-  it must instead be categorized with one of the `changelog-*` labels (which will be done by a
-  reviewer for external PRs).
-* A toolchain of the form `leanprover/lean4-pr-releases:pr-release-NNNN` for Linux and M-series Macs will be generated upon build. To generate binaries for Windows and Intel-based Macs as well, write a comment containing `release-ci` on its own line.
 * If you rebase your PR onto `nightly-with-mathlib` then CI will test Mathlib against your PR.
 * You can manage the `awaiting-review`, `awaiting-author`, and `WIP` labels yourself, by writing a comment containing one of these labels on its own line.
 * Remove this section, up to and including the `---` before submitting.
 
 ---
 
-This PR <short changelog summary for feat/fix, see above>.
-
-Closes <`RFC` or `bug` issue number fixed by this PR, if any>
+Closes #0000 (`RFC` or `bug` issue number fixed by this PR, if any)

.github/dependabot.yml

@@ -1,8 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-    commit-message:
-      prefix: "chore: CI"

.github/workflows/actionlint.yml

@@ -17,6 +17,6 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
     - name: actionlint
-      uses: raven-actions/actionlint@v2
+      uses: raven-actions/actionlint@v1
       with:
         pyflakes: false # we do not use python scripts

.github/workflows/check-prelude.yml

@@ -11,9 +11,7 @@ jobs:
         with:
           # the default is to use a virtual merge commit between the PR and master: just use the PR
           ref: ${{ github.event.pull_request.head.sha }}
-          sparse-checkout: |
-            src/Lean
-            src/Std
+          sparse-checkout: src/Lean
       - name: Check Prelude
         run: |
           failed_files=""
@@ -21,8 +19,8 @@ jobs:
             if ! grep -q "^prelude$" "$file"; then
               failed_files="$failed_files$file\n"
             fi
-          done < <(find src/Lean src/Std -name '*.lean' -print0)
+          done < <(find src/Lean -name '*.lean' -print0)
           if [ -n "$failed_files" ]; then
             echo -e "The following files should use 'prelude':\n$failed_files"
             exit 1
-          fi
+          fi

.github/workflows/ci.yml

@@ -114,7 +114,7 @@ jobs:
           elif [[ "${{ github.event_name }}" != "pull_request" ]]; then
             check_level=1
           else
-            labels="$(gh api repos/${{ github.repository_owner }}/${{ github.event.repository.name }}/pulls/${{ github.event.pull_request.number }} --jq '.labels')"
+            labels="$(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=2
             elif echo "$labels" | grep -q "merge-ci"; then
@@ -176,7 +176,7 @@ jobs:
                 "check-level": 2,
                 "CMAKE_PRESET": "debug",
                 // exclude seriously slow tests
-                "CTEST_OPTIONS": "-E 'interactivetest|leanpkgtest|laketest|benchtest|bv_bitblast_stress'"
+                "CTEST_OPTIONS": "-E 'interactivetest|leanpkgtest|laketest|benchtest'"
               },
               // TODO: suddenly started failing in CI
               /*{
@@ -204,7 +204,7 @@ jobs:
                 "os": "macos-14",
                 "CMAKE_OPTIONS": "-DLEAN_INSTALL_SUFFIX=-darwin_aarch64",
                 "release": true,
-                "check-level": 0,
+                "check-level": 1,
                 "shell": "bash -euxo pipefail {0}",
                 "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-aarch64-apple-darwin.tar.zst",
                 "prepare-llvm": "../script/prepare-llvm-macos.sh lean-llvm*",
@@ -217,7 +217,7 @@ jobs:
                 "release": true,
                 "check-level": 2,
                 "shell": "msys2 {0}",
-                "CMAKE_OPTIONS": "-G \"Unix Makefiles\"",
+                "CMAKE_OPTIONS": "-G \"Unix Makefiles\" -DUSE_GMP=OFF",
                 // for reasons unknown, interactivetests are flaky on Windows
                 "CTEST_OPTIONS": "--repeat until-pass:2",
                 "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-x86_64-w64-windows-gnu.tar.zst",
@@ -226,19 +226,21 @@ jobs:
               },
               {
                 "name": "Linux aarch64",
-                "os": "nscloud-ubuntu-22.04-arm64-4x8",
-                "CMAKE_OPTIONS": "-DLEAN_INSTALL_SUFFIX=-linux_aarch64",
+                "os": "ubuntu-latest",
+                "CMAKE_OPTIONS": "-DUSE_GMP=OFF -DLEAN_INSTALL_SUFFIX=-linux_aarch64",
                 "release": true,
                 "check-level": 2,
+                "cross": true,
+                "cross_target": "aarch64-unknown-linux-gnu",
                 "shell": "nix develop .#oldGlibcAArch -c bash -euxo pipefail {0}",
-                "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-aarch64-linux-gnu.tar.zst",
-                "prepare-llvm": "../script/prepare-llvm-linux.sh lean-llvm*"
+                "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-x86_64-linux-gnu.tar.zst https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-aarch64-linux-gnu.tar.zst",
+                "prepare-llvm": "../script/prepare-llvm-linux.sh lean-llvm-aarch64-* lean-llvm-x86_64-*"
               },
               {
                 "name": "Linux 32bit",
                 "os": "ubuntu-latest",
                 // Use 32bit on stage0 and stage1 to keep oleans compatible
-                "CMAKE_OPTIONS": "-DSTAGE0_USE_GMP=OFF -DSTAGE0_LEAN_EXTRA_CXX_FLAGS='-m32' -DSTAGE0_LEANC_OPTS='-m32' -DSTAGE0_MMAP=OFF -DUSE_GMP=OFF -DLEAN_EXTRA_CXX_FLAGS='-m32' -DLEANC_OPTS='-m32' -DMMAP=OFF -DLEAN_INSTALL_SUFFIX=-linux_x86 -DCMAKE_LIBRARY_PATH=/usr/lib/i386-linux-gnu/ -DSTAGE0_CMAKE_LIBRARY_PATH=/usr/lib/i386-linux-gnu/",
+                "CMAKE_OPTIONS": "-DSTAGE0_USE_GMP=OFF -DSTAGE0_LEAN_EXTRA_CXX_FLAGS='-m32' -DSTAGE0_LEANC_OPTS='-m32' -DSTAGE0_MMAP=OFF -DUSE_GMP=OFF -DLEAN_EXTRA_CXX_FLAGS='-m32' -DLEANC_OPTS='-m32' -DMMAP=OFF -DLEAN_INSTALL_SUFFIX=-linux_x86",
                 "cmultilib": true,
                 "release": true,
                 "check-level": 2,
@@ -249,7 +251,7 @@ jobs:
                 "name": "Web Assembly",
                 "os": "ubuntu-latest",
                 // Build a native 32bit binary in stage0 and use it to compile the oleans and the wasm build
-                "CMAKE_OPTIONS": "-DCMAKE_C_COMPILER_WORKS=1 -DSTAGE0_USE_GMP=OFF -DSTAGE0_LEAN_EXTRA_CXX_FLAGS='-m32' -DSTAGE0_LEANC_OPTS='-m32' -DSTAGE0_CMAKE_CXX_COMPILER=clang++ -DSTAGE0_CMAKE_C_COMPILER=clang -DSTAGE0_CMAKE_EXECUTABLE_SUFFIX=\"\" -DUSE_GMP=OFF -DMMAP=OFF -DSTAGE0_MMAP=OFF -DCMAKE_AR=../emsdk/emsdk-main/upstream/emscripten/emar -DCMAKE_TOOLCHAIN_FILE=../emsdk/emsdk-main/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DLEAN_INSTALL_SUFFIX=-linux_wasm32 -DSTAGE0_CMAKE_LIBRARY_PATH=/usr/lib/i386-linux-gnu/",
+                "CMAKE_OPTIONS": "-DCMAKE_C_COMPILER_WORKS=1 -DSTAGE0_USE_GMP=OFF -DSTAGE0_LEAN_EXTRA_CXX_FLAGS='-m32' -DSTAGE0_LEANC_OPTS='-m32' -DSTAGE0_CMAKE_CXX_COMPILER=clang++ -DSTAGE0_CMAKE_C_COMPILER=clang -DSTAGE0_CMAKE_EXECUTABLE_SUFFIX=\"\" -DUSE_GMP=OFF -DMMAP=OFF -DSTAGE0_MMAP=OFF -DCMAKE_AR=../emsdk/emsdk-main/upstream/emscripten/emar -DCMAKE_TOOLCHAIN_FILE=../emsdk/emsdk-main/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DLEAN_INSTALL_SUFFIX=-linux_wasm32",
                 "wasm": true,
                 "cmultilib": true,
                 "release": true,
@@ -257,7 +259,7 @@ jobs:
                 "cross": true,
                 "shell": "bash -euxo pipefail {0}",
                 // Just a few selected tests because wasm is slow
-                "CTEST_OPTIONS": "-R \"leantest_1007\\.lean|leantest_Format\\.lean|leanruntest\\_1037.lean|leanruntest_ac_rfl\\.lean|leanruntest_tempfile.lean\\.|leanruntest_libuv\\.lean\""
+                "CTEST_OPTIONS": "-R \"leantest_1007\\.lean|leantest_Format\\.lean|leanruntest\\_1037.lean|leanruntest_ac_rfl\\.lean\""
               }
             ];
             console.log(`matrix:\n${JSON.stringify(matrix, null, 2)}`)
@@ -296,12 +298,12 @@ jobs:
         uses: msys2/setup-msys2@v2
         with:
           msystem: clang64
-          # `:` means do not prefix with msystem
-          pacboy: "make: python: cmake clang ccache gmp libuv git: zip: unzip: diffutils: binutils: tree: zstd tar:"
+          # `:p` means prefix with appropriate msystem prefix
+          pacboy: "make python cmake:p clang:p ccache:p gmp:p git zip unzip diffutils binutils tree zstd:p tar"
         if: runner.os == 'Windows'
       - name: Install Brew Packages
         run: |
-          brew install ccache tree zstd coreutils gmp libuv
+          brew install ccache tree zstd coreutils gmp
         if: runner.os == 'macOS'
       - name: Checkout
         uses: actions/checkout@v4
@@ -316,28 +318,26 @@ jobs:
           git fetch --depth=1 origin ${{ github.sha }}
           git checkout FETCH_HEAD flake.nix flake.lock
         if: github.event_name == 'pull_request'
-      # (needs to be after "Checkout" so files don't get overridden)
+      # (needs to be after "Checkout" so files don't get overriden)
       - name: Setup emsdk
-        uses: mymindstorm/setup-emsdk@v14
+        uses: mymindstorm/setup-emsdk@v12
         with:
           version: 3.1.44
           actions-cache-folder: emsdk
         if: matrix.wasm
       - name: Install 32bit c libs
         run: |
-          sudo dpkg --add-architecture i386
           sudo apt-get update
-          sudo apt-get install -y gcc-multilib g++-multilib ccache libuv1-dev:i386
+          sudo apt-get install -y gcc-multilib g++-multilib ccache
         if: matrix.cmultilib
       - name: Cache
-        uses: actions/cache@v4
+        uses: actions/cache@v3
         with:
           path: .ccache
           key: ${{ matrix.name }}-build-v3-${{ github.event.pull_request.head.sha }}
           # fall back to (latest) previous cache
           restore-keys: |
             ${{ matrix.name }}-build-v3
-          save-always: true
       # open nix-shell once for initial setup
       - name: Setup
         run: |
@@ -382,12 +382,6 @@ jobs:
           make -C build install
       - name: Check Binaries
         run: ${{ matrix.binary-check }} lean-*/bin/* || true
-      - name: Count binary symbols
-        run: |
-          for f in lean-*/bin/*; do
-            echo "$f: $(nm $f | grep " T " | wc -l) exported symbols"
-          done
-        if: matrix.name == 'Windows'
       - name: List Install Tree
         run: |
           # omit contents of Init/, ...
@@ -432,7 +426,7 @@ jobs:
         if: matrix.test-speedcenter
       - name: Check Stage 3
         run: |
-          make -C build -j$NPROC check-stage3
+          make -C build -j$NPROC stage3
         if: matrix.test-speedcenter
       - name: Test Speedcenter Benchmarks
         run: |
@@ -452,7 +446,7 @@ jobs:
         run: ccache -s
 
   # This job collects results from all the matrix jobs
-  # This can be made the "required" job, instead of listing each
+  # This can be made the “required” job, instead of listing each
   # matrix job separately
   all-done:
     name: Build matrix complete
@@ -461,24 +455,12 @@ jobs:
     # mark as merely cancelled not failed if builds are cancelled
     if: ${{ !cancelled() }}
     steps:
-    - if: ${{ contains(needs.*.result, 'failure') && github.repository == 'leanprover/lean4' && github.ref_name == 'master' }}
-      uses: zulip/github-actions-zulip/send-message@v1
-      with:
-        api-key: ${{ secrets.ZULIP_BOT_KEY }}
-        email: "github-actions-bot@lean-fro.zulipchat.com"
-        organization-url: "https://lean-fro.zulipchat.com"
-        to: "infrastructure"
-        topic: "Github actions"
-        type: "stream"
-        content: |
-          A build of `${{ github.ref_name }}`, triggered by event `${{ github.event_name }}`, [failed](https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}).
     - if: contains(needs.*.result, 'failure')
       uses: actions/github-script@v7
       with:
         script: |
             core.setFailed('Some jobs failed')
 
-
   # This job creates releases from tags
   # (whether they are "unofficial" releases for experiments, or official releases when the tag is "v" followed by a semver string.)
   # We do not attempt to automatically construct a changelog here:
@@ -492,7 +474,7 @@ jobs:
         with:
           path: artifacts
       - name: Release
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v1
         with:
           files: artifacts/*/*
           fail_on_unmatched_files: true
@@ -536,7 +518,7 @@ 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@v2
+        uses: softprops/action-gh-release@v1
         with:
           body_path: diff.md
           prerelease: true
@@ -551,8 +533,3 @@ jobs:
           gh workflow -R leanprover/release-index run update-index.yml
         env:
           GITHUB_TOKEN: ${{ secrets.RELEASE_INDEX_TOKEN }}
-      - name: Update toolchain on mathlib4's nightly-testing branch
-        run: |
-          gh workflow -R leanprover-community/mathlib4 run nightly_bump_toolchain.yml
-        env:
-          GITHUB_TOKEN: ${{ secrets.MATHLIB4_BOT }}

.github/workflows/jira.yml

@@ -1,34 +0,0 @@
-name: Jira sync
-
-on:
-  issues:
-    types: [closed]
-
-jobs:
-  jira-sync:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Move Jira issue to Done
-        env:
-          JIRA_API_TOKEN: ${{ secrets.JIRA_API_TOKEN }}
-          JIRA_USERNAME: ${{ secrets.JIRA_USERNAME }}
-          JIRA_BASE_URL: ${{ secrets.JIRA_BASE_URL }}
-        run: |
-          issue_number=${{ github.event.issue.number }}
-
-          jira_issue_key=$(curl -s -u "${JIRA_USERNAME}:${JIRA_API_TOKEN}" \
-            -X GET -H "Content-Type: application/json" \
-            "${JIRA_BASE_URL}/rest/api/2/search?jql=summary~\"${issue_number}\"" | \
-            jq -r '.issues[0].key')
-
-          if [ -z "$jira_issue_key" ]; then
-            exit
-          fi
-
-          curl -s -u "${JIRA_USERNAME}:${JIRA_API_TOKEN}" \
-            -X POST -H "Content-Type: application/json" \
-            --data "{\"transition\": {\"id\": \"41\"}}" \
-            "${JIRA_BASE_URL}/rest/api/2/issue/${jira_issue_key}/transitions"
-
-          echo "Moved Jira issue ${jira_issue_key} to Done"

.github/workflows/labels-from-comments.yml

@@ -1,8 +1,6 @@
-# This workflow allows any user to add one of the `awaiting-review`, `awaiting-author`, `WIP`,
-# `release-ci`, or a `changelog-XXX` label by commenting on the PR or issue.
-# If any labels from the set {`awaiting-review`, `awaiting-author`, `WIP`} are added, other labels
-# from that set are removed automatically at the same time.
-# Similarly, if any `changelog-XXX` label is added, other `changelog-YYY` labels are removed.
+# This workflow allows any user to add one of the `awaiting-review`, `awaiting-author`, or `WIP` labels,
+# by commenting on the PR or issue.
+# Other labels from this set are removed automatically at the same time.
 
 name: Label PR based on Comment
 
@@ -12,7 +10,7 @@ on:
 
 jobs:
   update-label:
-    if: github.event.issue.pull_request != null && (contains(github.event.comment.body, 'awaiting-review') || contains(github.event.comment.body, 'awaiting-author') || contains(github.event.comment.body, 'WIP') || contains(github.event.comment.body, 'release-ci') || contains(github.event.comment.body, 'changelog-'))
+    if: github.event.issue.pull_request != null && (contains(github.event.comment.body, 'awaiting-review') || contains(github.event.comment.body, 'awaiting-author') || contains(github.event.comment.body, 'WIP'))
     runs-on: ubuntu-latest
 
     steps:
@@ -21,14 +19,12 @@ jobs:
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}
         script: |
-          const { owner, repo, number: issue_number } = context.issue;
+          const { owner, repo, number: issue_number  } = context.issue;
           const commentLines = context.payload.comment.body.split('\r\n');
 
           const awaitingReview = commentLines.includes('awaiting-review');
           const awaitingAuthor = commentLines.includes('awaiting-author');
           const wip = commentLines.includes('WIP');
-          const releaseCI = commentLines.includes('release-ci');
-          const changelogMatch = commentLines.find(line => line.startsWith('changelog-'));
 
           if (awaitingReview || awaitingAuthor || wip) {
             await github.rest.issues.removeLabel({ owner, repo, issue_number, name: 'awaiting-review' }).catch(() => {});
@@ -45,23 +41,3 @@ jobs:
           if (wip) {
             await github.rest.issues.addLabels({ owner, repo, issue_number, labels: ['WIP'] });
           }
-
-          if (releaseCI) {
-            await github.rest.issues.addLabels({ owner, repo, issue_number, labels: ['release-ci'] });
-          }
-
-          if (changelogMatch) {
-            const changelogLabel = changelogMatch.trim();
-            const { data: existingLabels } = await github.rest.issues.listLabelsOnIssue({ owner, repo, issue_number });
-            const changelogLabels = existingLabels.filter(label => label.name.startsWith('changelog-'));
-
-            // Remove all other changelog labels
-            for (const label of changelogLabels) {
-              if (label.name !== changelogLabel) {
-                await github.rest.issues.removeLabel({ owner, repo, issue_number, name: label.name }).catch(() => {});
-              }
-            }
-
-            // Add the new changelog label
-            await github.rest.issues.addLabels({ owner, repo, issue_number, labels: [changelogLabel] });
-          }

.github/workflows/nix-ci.yml

@@ -55,14 +55,13 @@ jobs:
           # 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: Set Up Nix Cache
-        uses: actions/cache@v4
+        uses: actions/cache@v3
         with:
           path: nix-store-cache
           key: ${{ matrix.name }}-nix-store-cache-${{ github.sha }}
           # fall back to (latest) previous cache
           restore-keys: |
             ${{ matrix.name }}-nix-store-cache
-          save-always: true
       - name: Further Set Up Nix Cache
         shell: bash -euxo pipefail {0}
         run: |
@@ -79,14 +78,13 @@ jobs:
           sudo mkdir -m0770 -p /nix/var/cache/ccache
           sudo chown -R $USER /nix/var/cache/ccache
       - name: Setup CCache Cache
-        uses: actions/cache@v4
+        uses: actions/cache@v3
         with:
           path: /nix/var/cache/ccache
           key: ${{ matrix.name }}-nix-ccache-${{ github.sha }}
           # fall back to (latest) previous cache
           restore-keys: |
             ${{ matrix.name }}-nix-ccache
-          save-always: true
       - name: Further Set Up CCache Cache
         run: |
           sudo chown -R root:nixbld /nix/var/cache
@@ -96,7 +94,7 @@ jobs:
           nix build $NIX_BUILD_ARGS .#cacheRoots -o push-build
       - name: Test
         run: |
-          nix build --keep-failed $NIX_BUILD_ARGS .#test -o push-test || (ln -s /tmp/nix-build-*/build/source/src/build ./push-test; false)
+          nix build --keep-failed $NIX_BUILD_ARGS .#test -o push-test || (ln -s /tmp/nix-build-*/source/src/build/ ./push-test; false)
       - name: Test Summary
         uses: test-summary/action@v2
         with:
@@ -105,11 +103,19 @@ jobs:
         continue-on-error: true
       - name: Build manual
         run: |
-          nix build $NIX_BUILD_ARGS --update-input lean --no-write-lock-file ./doc#{lean-mdbook,leanInk,alectryon,inked} -o push-doc
+          nix build $NIX_BUILD_ARGS --update-input lean --no-write-lock-file ./doc#{lean-mdbook,leanInk,alectryon,test,inked} -o push-doc
           nix build $NIX_BUILD_ARGS --update-input lean --no-write-lock-file ./doc
           # https://github.com/netlify/cli/issues/1809
           cp -r --dereference ./result ./dist
         if: matrix.name == 'Nix Linux'
+      - name: Check manual for broken links
+        id: lychee
+        uses: lycheeverse/lychee-action@v1.9.0
+        with:
+          fail: false  # report errors but do not block CI on temporary failures
+          # gmplib.org consistently times out from GH actions
+          # the GitHub token is to avoid rate limiting
+          args: --base './dist' --no-progress --github-token ${{ secrets.GITHUB_TOKEN }} --exclude 'gmplib.org' './dist/**/*.html'
       - name: Rebuild Nix Store Cache
         run: |
           rm -rf nix-store-cache || true
@@ -121,7 +127,7 @@ jobs:
           python3 -c 'import base64; print("alias="+base64.urlsafe_b64encode(bytes.fromhex("${{github.sha}}")).decode("utf-8").rstrip("="))' >> "$GITHUB_OUTPUT"
           echo "message=`git log -1 --pretty=format:"%s"`" >> "$GITHUB_OUTPUT"
       - name: Publish manual to Netlify
-        uses: nwtgck/actions-netlify@v3.0
+        uses: nwtgck/actions-netlify@v2.0
         id: publish-manual
         with:
           publish-dir: ./dist
@@ -140,3 +146,5 @@ jobs:
       - name: Fixup CCache Cache
         run: |
           sudo chown -R $USER /nix/var/cache
+      - name: CCache stats
+        run: CCACHE_DIR=/nix/var/cache/ccache nix run .#nixpkgs.ccache -- -s

.github/workflows/pr-body.yml

@@ -1,25 +0,0 @@
-name: Check PR body for changelog convention
-
-on:
-  merge_group:
-  pull_request:
-    types: [opened, synchronize, reopened, edited, labeled, converted_to_draft, ready_for_review]
-
-jobs:
-  check-pr-body:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check PR body
-        if: github.event_name == 'pull_request'
-        uses: actions/github-script@v7
-        with:
-          script: |
-            const { title, body, labels, draft } = context.payload.pull_request;
-            if (!draft && /^(feat|fix):/.test(title) && !labels.some(label => label.name == "changelog-no")) {
-              if (!labels.some(label => label.name.startsWith("changelog-"))) {
-                core.setFailed('feat/fix PR must have a `changelog-*` label');
-              }
-              if (!/^This PR [^<]/.test(body)) {
-                core.setFailed('feat/fix PR must have changelog summary starting with "This PR ..." as first line.');
-              }
-            }

.github/workflows/pr-release.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Download artifact from the previous workflow.
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         id: download-artifact
-        uses: dawidd6/action-download-artifact@v6 # https://github.com/marketplace/actions/download-workflow-artifact
+        uses: dawidd6/action-download-artifact@v2 # https://github.com/marketplace/actions/download-workflow-artifact
         with:
           run_id: ${{ github.event.workflow_run.id }}
           path: artifacts
@@ -60,7 +60,7 @@ jobs:
           GH_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
       - name: Release
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v1
         with:
           name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }}
           # There are coredumps files here as well, but all in deeper subdirectories.
@@ -75,7 +75,7 @@ jobs:
 
       - name: Report release status
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: actions/github-script@v7
+        uses: actions/github-script@v6
         with:
           script: |
             await github.rest.repos.createCommitStatus({
@@ -111,7 +111,7 @@ jobs:
 
       - name: 'Setup jq'
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: dcarbone/install-jq-action@v2.1.0
+        uses: dcarbone/install-jq-action@v1.0.1
 
       # Check that the most recently nightly coincides with 'git merge-base HEAD master'
       - name: Check merge-base and nightly-testing-YYYY-MM-DD
@@ -134,7 +134,7 @@ jobs:
               MESSAGE=""
 
               if [[ -n "$MATHLIB_REMOTE_TAGS" ]]; then
-                echo "... and Mathlib has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
+                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."
@@ -149,7 +149,7 @@ jobs:
             echo "but 'git merge-base origin/master HEAD' reported: $MERGE_BASE_SHA"
             git -C lean4.git log -10 origin/master
 
-            git -C lean4.git fetch origin nightly-with-mathlib
+            git -C lean4.git fetch origin nightly-with-mathlib 
             NIGHTLY_WITH_MATHLIB_SHA="$(git -C lean4.git rev-parse "origin/nightly-with-mathlib")"
             MESSAGE="- ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the \`nightly-with-mathlib\` branch. Try \`git rebase $MERGE_BASE_SHA --onto $NIGHTLY_WITH_MATHLIB_SHA\`."
           fi
@@ -163,11 +163,10 @@ jobs:
             # so keep in sync
 
             # Use GitHub API to check if a comment already exists
-            existing_comment="$(curl --retry 3 --location --silent \
-                                    -H "Authorization: token ${{ secrets.MATHLIB4_COMMENT_BOT }}" \
+            existing_comment="$(curl -L -s -H "Authorization: token ${{ secrets.MATHLIB4_BOT }}" \
                                     -H "Accept: application/vnd.github.v3+json" \
                                     "https://api.github.com/repos/leanprover/lean4/issues/${{ steps.workflow-info.outputs.pullRequestNumber }}/comments" \
-                                    | jq 'first(.[] | select(.body | test("^- . Mathlib") or startswith("Mathlib CI status")) | select(.user.login == "leanprover-community-bot"))')"
+                                    | jq 'first(.[] | select(.body | test("^- . Mathlib") or startswith("Mathlib CI status")) | select(.user.login == "leanprover-community-mathlib4-bot"))')"
             existing_comment_id="$(echo "$existing_comment" | jq -r .id)"
             existing_comment_body="$(echo "$existing_comment" | jq -r .body)"
 
@@ -177,14 +176,14 @@ jobs:
               echo "Posting message to the comments: $MESSAGE"
 
               # Append new result to the existing comment or post a new comment
-              # It's essential we use the MATHLIB4_COMMENT_BOT token here, so that Mathlib CI can subsequently edit the comment.
+              # It's essential we use the MATHLIB4_BOT token here, so that Mathlib CI can subsequently edit the comment.
               if [ -z "$existing_comment_id" ]; then
                 INTRO="Mathlib CI status ([docs](https://leanprover-community.github.io/contribute/tags_and_branches.html)):"
                 # Post new comment with a bullet point
                 echo "Posting as new comment at leanprover/lean4/issues/${{ steps.workflow-info.outputs.pullRequestNumber }}/comments"
                 curl -L -s \
                   -X POST \
-                  -H "Authorization: token ${{ secrets.MATHLIB4_COMMENT_BOT }}" \
+                  -H "Authorization: token ${{ secrets.MATHLIB4_BOT }}" \
                   -H "Accept: application/vnd.github.v3+json" \
                   -d "$(jq --null-input --arg intro "$INTRO" --arg val "$MESSAGE" '{"body":($intro + "\n" + $val)}')" \
                   "https://api.github.com/repos/leanprover/lean4/issues/${{ steps.workflow-info.outputs.pullRequestNumber }}/comments"
@@ -193,7 +192,7 @@ jobs:
                 echo "Appending to existing comment at leanprover/lean4/issues/${{ steps.workflow-info.outputs.pullRequestNumber }}/comments"
                 curl -L -s \
                   -X PATCH \
-                  -H "Authorization: token ${{ secrets.MATHLIB4_COMMENT_BOT }}" \
+                  -H "Authorization: token ${{ secrets.MATHLIB4_BOT }}" \
                   -H "Accept: application/vnd.github.v3+json" \
                   -d "$(jq --null-input --arg existing "$existing_comment_body" --arg message "$MESSAGE" '{"body":($existing + "\n" + $message)}')" \
                   "https://api.github.com/repos/leanprover/lean4/issues/comments/$existing_comment_id"
@@ -208,7 +207,7 @@ jobs:
 
       - name: Report mathlib base
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true' }}
-        uses: actions/github-script@v7
+        uses: actions/github-script@v6
         with:
           script: |
             const description =
@@ -329,18 +328,16 @@ jobs:
             git switch -c lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }} "$BASE"
             echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}" > lean-toolchain
             git add lean-toolchain
-            sed -i 's,require "leanprover-community" / "batteries" @ git ".\+",require "leanprover-community" / "batteries" @ git "lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}",' lakefile.lean
+            sed -i 's,require "leanprover-community" / "batteries" @ ".\+",require "leanprover-community" / "batteries" @ "git#nightly-testing-'"${MOST_RECENT_NIGHTLY}"'",' lakefile.lean
             lake update batteries
             git add lakefile.lean lake-manifest.json
             git commit -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           else
-            echo "Branch already exists, merging $BASE and bumping Batteries."
+            echo "Branch already exists, pushing an empty commit."
             git switch lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
             # The Mathlib `nightly-testing` branch or `nightly-testing-YYYY-MM-DD` tag may have moved since this branch was created, so merge their changes.
             # (This should no longer be possible once `nightly-testing-YYYY-MM-DD` is a tag, but it is still safe to merge.)
             git merge "$BASE" --strategy-option ours --no-commit --allow-unrelated-histories
-            lake update batteries
-            git add lake-manifest.json
             git commit --allow-empty -m "Trigger CI for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 

.github/workflows/restart-on-label.yml

@@ -14,9 +14,8 @@ jobs:
         # (unfortunately cannot search by PR number, only base branch,
         # and that is't even unique given PRs from forks, but the risk
         # of confusion is low and the danger is mild)
-        echo "Trying to find a run with branch $head_ref and commit $head_sha"
-        run_id="$(gh run list -e pull_request -b "$head_ref" -c "$head_sha" \
-          --workflow 'CI' --limit 1 --json databaseId --jq '.[0].databaseId')"
+        run_id=$(gh run list -e pull_request -b "$head_ref" --workflow 'CI' --limit 1 \
+          --limit 1 --json databaseId --jq '.[0].databaseId')
         echo "Run id: ${run_id}"
         gh run view "$run_id"
         echo "Cancelling (just in case)"
@@ -30,6 +29,5 @@ jobs:
       shell: bash
       env:
         head_ref: ${{ github.head_ref }}
-        head_sha: ${{ github.event.pull_request.head.sha }}
         GH_TOKEN: ${{ github.token }}
         GH_REPO: ${{ github.repository }}

.github/workflows/stale.yml

@@ -11,7 +11,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/stale@v9
+      - uses: actions/stale@v8
         with:
           days-before-stale: -1
           days-before-pr-stale: 30

.github/workflows/update-stage0.yml

@@ -47,7 +47,7 @@ jobs:
     #  uses: DeterminateSystems/magic-nix-cache-action@v2
     - if: env.should_update_stage0 == 'yes'
       name: Restore Build Cache
-      uses: actions/cache/restore@v4
+      uses: actions/cache/restore@v3
       with:
         path: nix-store-cache
         key: Nix Linux-nix-store-cache-${{ github.sha }}

CMakeLists.txt

@@ -30,35 +30,6 @@ if(NOT (DEFINED STAGE0_CMAKE_EXECUTABLE_SUFFIX))
     set(STAGE0_CMAKE_EXECUTABLE_SUFFIX "${CMAKE_EXECUTABLE_SUFFIX}")
 endif()
 
-# Don't do anything with cadical on wasm
-if (NOT ${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
-  # On CI Linux, we source cadical from Nix instead; see flake.nix
-  find_program(CADICAL cadical)
-  if(NOT CADICAL)
-    set(CADICAL_CXX c++)
-    find_program(CCACHE ccache)
-    if(CCACHE)
-      set(CADICAL_CXX "${CCACHE} ${CADICAL_CXX}")
-    endif()
-    # missing stdio locking API on Windows
-    if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-      string(APPEND CADICAL_CXXFLAGS " -DNUNLOCKED")
-    endif()
-    ExternalProject_add(cadical
-      PREFIX cadical
-      GIT_REPOSITORY https://github.com/arminbiere/cadical
-      GIT_TAG rel-1.9.5
-      CONFIGURE_COMMAND ""
-      # https://github.com/arminbiere/cadical/blob/master/BUILD.md#manual-build
-      BUILD_COMMAND $(MAKE) -f ${CMAKE_SOURCE_DIR}/src/cadical.mk CMAKE_EXECUTABLE_SUFFIX=${CMAKE_EXECUTABLE_SUFFIX} CXX=${CADICAL_CXX} CXXFLAGS=${CADICAL_CXXFLAGS}
-      BUILD_IN_SOURCE ON
-      INSTALL_COMMAND "")
-    set(CADICAL ${CMAKE_BINARY_DIR}/cadical/cadical${CMAKE_EXECUTABLE_SUFFIX} CACHE FILEPATH "path to cadical binary" FORCE)
-    set(EXTRA_DEPENDS "cadical")
-  endif()
-  list(APPEND CL_ARGS -DCADICAL=${CADICAL})
-endif()
-
 ExternalProject_add(stage0
   SOURCE_DIR "${LEAN_SOURCE_DIR}/stage0"
   SOURCE_SUBDIR src

CODEOWNERS

@@ -4,14 +4,14 @@
 # Listed persons will automatically be asked by GitHub to review a PR touching these paths.
 # If multiple names are listed, a review by any of them is considered sufficient by default.
 
-/.github/ @Kha @kim-em
-/RELEASES.md @kim-em
+/.github/ @Kha @semorrison
+/RELEASES.md @semorrison
 /src/kernel/ @leodemoura
 /src/lake/ @tydeu
 /src/Lean/Compiler/ @leodemoura
 /src/Lean/Data/Lsp/ @mhuisi
-/src/Lean/Elab/Deriving/ @kim-em
-/src/Lean/Elab/Tactic/ @kim-em
+/src/Lean/Elab/Deriving/ @semorrison
+/src/Lean/Elab/Tactic/ @semorrison
 /src/Lean/Language/ @Kha
 /src/Lean/Meta/Tactic/ @leodemoura
 /src/Lean/Parser/ @Kha
@@ -19,7 +19,7 @@
 /src/Lean/PrettyPrinter/Delaborator/ @kmill
 /src/Lean/Server/ @mhuisi
 /src/Lean/Widget/ @Vtec234
-/src/Init/Data/ @kim-em
+/src/Init/Data/ @semorrison
 /src/Init/Data/Array/Lemmas.lean @digama0
 /src/Init/Data/List/Lemmas.lean @digama0
 /src/Init/Data/List/BasicAux.lean @digama0
@@ -43,6 +43,3 @@
 /src/Init/Guard.lean @digama0
 /src/Lean/Server/CodeActions/ @digama0
 /src/Std/ @TwoFX
-/src/Std/Tactic/BVDecide/ @hargoniX
-/src/Lean/Elab/Tactic/BVDecide/ @hargoniX
-/src/Std/Sat/ @hargoniX

CONTRIBUTING.md

@@ -63,20 +63,6 @@ Because the change will be squashed, there is no need to polish the commit messa
 Reviews and Feedback:
 ----
 
-The lean4 repo is managed by the Lean FRO's *triage team* that aims to provide initial feedback on new bug reports, PRs, and RFCs weekly.
-This feedback generally consists of prioritizing the ticket using one of the following categories:
-* label `P-high`: We will work on this issue
-* label `P-medium`: We may work on this issue if we find the time
-* label `P-low`: We are not planning to work on this issue
-* *closed*: This issue is already fixed, it is not an issue, or is not sufficiently compatible with our roadmap for the project and we will not work on it nor accept external contributions on it
-
-For *bug reports*, the listed priority reflects our commitment to fixing the issue.
-It is generally indicative but not necessarily identical to the priority an external contribution addressing this bug would receive.
-For *PRs* and *RFCs*, the priority reflects our commitment to reviewing them and getting them to an acceptable state.
-Accepted RFCs are marked with the label `RFC accepted` and afterwards assigned a new "implementation" priority as with bug reports.
-
-General guidelines for interacting with reviews and feedback:
-
 **Be Patient**: Given the limited number of full-time maintainers and the volume of PRs, reviews may take some time.
 
 **Engage Constructively**: Always approach feedback positively and constructively. Remember, reviews are about ensuring the best quality for the project, not personal criticism.

LICENSES

@@ -1341,33 +1341,3 @@ whether future versions of the GNU Lesser General Public License shall
 apply, that proxy's public statement of acceptance of any version is
 permanent authorization for you to choose that version for the
 Library.
-==============================================================================
-CaDiCaL is under the MIT License:
-==============================================================================
-MIT License
-
-Copyright (c) 2016-2021 Armin Biere, Johannes Kepler University Linz, Austria
-Copyright (c) 2020-2021 Mathias Fleury, Johannes Kepler University Linz, Austria
-Copyright (c) 2020-2021 Nils Froleyks, Johannes Kepler University Linz, Austria
-Copyright (c) 2022-2024 Katalin Fazekas, Vienna University of Technology, Austria
-Copyright (c) 2021-2024 Armin Biere, University of Freiburg, Germany
-Copyright (c) 2021-2024 Mathias Fleury, University of Freiburg, Germany
-Copyright (c) 2023-2024 Florian Pollitt, University of Freiburg, Germany
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

debug.log

@@ -1 +0,0 @@
-[0829/202002.254:ERROR:crashpad_client_win.cc(868)] not connected

doc/dev/bootstrap.md

@@ -73,7 +73,7 @@ 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.
 
-If you have write access to the lean4 repository, you can also manually
+If you have write access to the lean4 repository, you can also also manually
 trigger that process, for example to be able to use new features in the compiler itself.
 You can do that on <https://github.com/leanprover/lean4/actions/workflows/update-stage0.yml>
 or using Github CLI with

doc/dev/debugging.md

@@ -5,7 +5,7 @@ Some notes on how to debug Lean, which may also be applicable to debugging Lean
 
 ## Tracing
 
-In `CoreM` and derived monads, we use `trace[traceCls] "msg with {interpolations}"` to fill the structured trace viewable with `set_option trace.traceCls true`.
+In `CoreM` and derived monads, we use `trace![traceCls] "msg with {interpolations}"` to fill the structured trace viewable with `set_option trace.traceCls true`.
 New trace classes have to be registered using `registerTraceClass` first.
 
 Notable trace classes:
@@ -22,9 +22,7 @@ Notable trace classes:
 
 In pure contexts or when execution is aborted before the messages are finally printed, one can instead use the term `dbg_trace "msg with {interpolations}"; val` (`;` can also be replaced by a newline), which will print the message to stderr before evaluating `val`. `dbgTraceVal val` can be used as a shorthand for `dbg_trace "{val}"; val`.
 Note that if the return value is not actually used, the trace code is silently dropped as well.
-
-By default, such stderr output is buffered and shown as messages after a command has been elaborated, which is necessary to ensure deterministic ordering of messages under parallelism.
-If Lean aborts the process before it can finish the command or takes too long to do that, using `-DstderrAsMessages=false` avoids this buffering and shows `dbg_trace` output (but not `trace`s or other diagnostics) immediately.
+In the language server, stderr output is buffered and shown as messages after a command has been elaborated, unless the option `server.stderrAsMessages` is deactivated.
 
 ## Debuggers
 

doc/dev/release_checklist.md

@@ -5,11 +5,8 @@ See below for the checklist for release candidates.
 
 We'll use `v4.6.0` as the intended release version as a running example.
 
-- One week before the planned release, ensure that
-  (1) someone has written the release notes and
-  (2) someone has written the first draft of the release blog post.
-  If there is any material in `./releases_drafts/` on the `releases/v4.6.0` branch, then the release notes are not done.
-  (See the section "Writing the release notes".)
+- One week before the planned release, ensure that (1) someone has written the release notes and (2) someone has written the first draft of the release blog post.
+  If there is any material in `./releases_drafts/`, then the release notes are not done. (See the section "Writing the release notes".)
 - `git checkout releases/v4.6.0`
   (This branch should already exist, from the release candidates.)
 - `git pull`
@@ -71,12 +68,6 @@ We'll use `v4.6.0` as the intended release version as a running example.
       - Toolchain bump PR including updated Lake manifest
       - Create and push the tag
       - There is no `stable` branch; skip this step
-    - [Verso](https://github.com/leanprover/verso)
-      - Dependencies: exist, but they're not part of the release workflow
-      - The `SubVerso` dependency should be compatible with _every_ Lean release simultaneously, rather than following this workflow
-      - Toolchain bump PR including updated Lake manifest
-      - Create and push the tag
-      - There is no `stable` branch; skip this step
     - [import-graph](https://github.com/leanprover-community/import-graph)
       - Toolchain bump PR including updated Lake manifest
       - Create and push the tag
@@ -153,31 +144,33 @@ We'll use `v4.7.0-rc1` as the intended release version in this example.
   - You can monitor this at `https://github.com/leanprover/lean4/actions/workflows/ci.yml`, looking for the `v4.7.0-rc1` tag.
   - This step can take up to an hour.
 - (GitHub release notes) Once the release appears at https://github.com/leanprover/lean4/releases/
-  - Verify that the release is marked as a prerelease (this should have been done automatically by the CI release job).
-  - In the "previous tag" dropdown, select `v4.6.0`, and click "Generate release notes".
+  - Edit the release notes on Github to select the "Set as a pre-release box".
+  - If release notes have been written already, copy the section of `RELEASES.md` for this version into the Github release notes
+    and use the title "Changes since v4.6.0 (from RELEASES.md)".
+  - Otherwise, in the "previous tag" dropdown, select `v4.6.0`, and click "Generate release notes".
     This will add a list of all the commits since the last stable version.
+    - Delete anything already mentioned in the hand-written release notes above.
     - Delete "update stage0" commits, and anything with a completely inscrutable commit message.
+    - Briefly rearrange the remaining items by category (e.g. `simp`, `lake`, `bug fixes`),
+      but for minor items don't put any work in expanding on commit messages.
+  - (How we want to release notes to look is evolving: please update this section if it looks wrong!)
 - Next, we will move a curated list of downstream repos to the release candidate.
-  - This assumes that for each repository either:
-    * There is already a *reviewed* branch `bump/v4.7.0` containing the required adaptations.
-      The preparation of this branch is beyond the scope of this document.
-    * The repository does not need any changes to move to the new version.
+  - This assumes that there is already a *reviewed* branch `bump/v4.7.0` on each repository
+    containing the required adaptations (or no adaptations are required).
+    The preparation of this branch is beyond the scope of this document.
   - For each of the target repositories:
-    - If the repository does not need any changes (i.e. `bump/v4.7.0` does not exist) then create
-      a new PR updating `lean-toolchain` to `leanprover/lean4:v4.7.0-rc1` and running `lake update`.
-    - Otherwise:
-      - Checkout the `bump/v4.7.0` branch.
-      - Verify that the `lean-toolchain` is set to the nightly from which the release candidate was created.
-      - `git merge origin/master`
-      - Change the `lean-toolchain` to `leanprover/lean4:v4.7.0-rc1`
-      - In `lakefile.lean`, change any dependencies which were using `nightly-testing` or `bump/v4.7.0` branches
-        back to `master` or `main`, and run `lake update` for those dependencies.
-      - Run `lake build` to ensure that dependencies are found (but it's okay to stop it after a moment).
-      - `git commit`
-      - `git push`
-      - Open a PR from `bump/v4.7.0` to `master`, and either merge it yourself after CI, if appropriate,
-        or notify the maintainers that it is ready to go.
-    - Once the PR has been merged, tag `master` with `v4.7.0-rc1` and push this tag.
+    - Checkout the `bump/v4.7.0` branch.
+    - Verify that the `lean-toolchain` is set to the nightly from which the release candidate was created.
+    - `git merge origin/master`
+    - Change the `lean-toolchain` to `leanprover/lean4:v4.7.0-rc1`
+    - In `lakefile.lean`, change any dependencies which were using `nightly-testing` or `bump/v4.7.0` branches
+      back to `master` or `main`, and run `lake update` for those dependencies.
+    - Run `lake build` to ensure that dependencies are found (but it's okay to stop it after a moment).
+    - `git commit`
+    - `git push`
+    - Open a PR from `bump/v4.7.0` to `master`, and either merge it yourself after CI, if appropriate,
+      or notify the maintainers that it is ready to go.
+    - Once this PR has been merged, tag `master` with `v4.7.0-rc1` and push this tag.
   - We do this for the same list of repositories as for stable releases, see above.
     As above, there are dependencies between these, and so the process above is iterative.
     It greatly helps if you can merge the `bump/v4.7.0` PRs yourself!
@@ -194,11 +187,9 @@ We'll use `v4.7.0-rc1` as the intended release version in this example.
   Please also make sure that whoever is handling social media knows the release is out.
 - Begin the next development cycle (i.e. for `v4.8.0`) on the Lean repository, by making a PR that:
   - Updates `src/CMakeLists.txt` to say `set(LEAN_VERSION_MINOR 8)`
-  - Replaces the "release notes will be copied" text in the `v4.6.0` section of `RELEASES.md` with the
-    finalized release notes from the `releases/v4.6.0` branch.
   - Replaces the "development in progress" in the `v4.7.0` section of `RELEASES.md` with
     ```
-    Release candidate, release notes will be copied from the branch `releases/v4.7.0` once completed.
+    Release candidate, release notes will be copied from `branch releases/v4.7.0` once completed.
     ```
     and inserts the following section before that section:
     ```
@@ -207,8 +198,6 @@ We'll use `v4.7.0-rc1` as the intended release version in this example.
     Development in progress.
     ```
   - Removes all the entries from the `./releases_drafts/` folder.
-  - Titled "chore: begin development cycle for v4.8.0"
-
 
 ## Time estimates:
 Slightly longer than the corresponding steps for a stable release.
@@ -233,15 +222,12 @@ Please read https://leanprover-community.github.io/contribute/tags_and_branches.
   * This can either be done by the person managing this process directly,
     or by soliciting assistance from authors of files, or generally helpful people on Zulip!
 * Each repo has a `bump/v4.7.0` which accumulates reviewed changes adapting to new versions.
-* Once `nightly-testing` is working on a given nightly, say `nightly-2024-02-15`, we will create a PR to `bump/v4.7.0`.
-* For Mathlib, there is a script in `scripts/create-adaptation-pr.sh` that automates this process.
-* For Batteries and Aesop it is currently manual.
-* For all of these repositories, the process is the same:
+* Once `nightly-testing` is working on a given nightly, say `nightly-2024-02-15`, we:
   * Make sure `bump/v4.7.0` is up to date with `master` (by merging `master`, no PR necessary)
   * Create from `bump/v4.7.0` a `bump/nightly-2024-02-15` branch.
-  * In that branch, `git merge nightly-testing` to bring across changes from `nightly-testing`.
+  * In that branch, `git merge --squash nightly-testing` to bring across changes from `nightly-testing`.
   * Sanity check changes, commit, and make a PR to `bump/v4.7.0` from the `bump/nightly-2024-02-15` branch.
-  * Solicit review, merge the PR into `bump/v4.7.0`.
+  * Solicit review, merge the PR into `bump/v4,7,0`.
 * It is always okay to merge in the following directions:
   `master` -> `bump/v4.7.0` -> `bump/nightly-2024-02-15` -> `nightly-testing`.
   Please remember to push any merges you make to intermediate steps!
@@ -253,7 +239,7 @@ The exact steps are a work in progress.
 Here is the general idea:
 
 * The work is done right on the `releases/v4.6.0` branch sometime after it is created but before the stable release is made.
-  The release notes for `v4.6.0` will later be copied to `master` when we begin a new development cycle.
+  The release notes for `v4.6.0` will be copied to `master`.
 * There can be material for release notes entries in commit messages.
 * There can also be pre-written entries in `./releases_drafts`, which should be all incorporated in the release notes and then deleted from the branch.
   See `./releases_drafts/README.md` for more information.

doc/examples/ICERM2022/ctor.lean

@@ -18,7 +18,7 @@ def ctor (mvarId : MVarId) (idx : Nat) : MetaM (List MVarId) := do
     else if h : idx - 1 < ctors.length then
       mvarId.apply (.const ctors[idx - 1] us)
     else
-      throwTacticEx `ctor mvarId "invalid index, inductive datatype has only {ctors.length} constructors"
+      throwTacticEx `ctor mvarId "invalid index, inductive datatype has only {ctors.length} contructors"
 
 open Elab Tactic
 

doc/examples/deBruijn.lean

@@ -149,7 +149,7 @@ We now define the constant folding optimization that traverses a term if replace
 /-!
 The correctness of the `Term.constFold` is proved using induction, case-analysis, and the term simplifier.
 We prove all cases but the one for `plus` using `simp [*]`. This tactic instructs the term simplifier to
-use hypotheses such as `a = b` as rewriting/simplifications rules.
+use hypotheses such as `a = b` as rewriting/simplications rules.
 We use the `split` to break the nested `match` expression in the `plus` case into two cases.
 The local variables `iha` and `ihb` are the induction hypotheses for `a` and `b`.
 The modifier `←` in a term simplifier argument instructs the term simplifier to use the equation as a rewriting rule in

doc/examples/interp.lean

@@ -149,4 +149,4 @@ def fact : Expr ctx (Ty.fn Ty.int Ty.int) :=
            (op (·*·) (delay fun _ => app fact (op (·-·) (var stop) (val 1))) (var stop)))
   decreasing_by sorry
 
-#eval! fact.interp Env.nil 10
+#eval fact.interp Env.nil 10

doc/examples/phoas.lean

@@ -225,7 +225,7 @@ We now define the constant folding optimization that traverses a term if replace
 /-!
 The correctness of the `constFold` is proved using induction, case-analysis, and the term simplifier.
 We prove all cases but the one for `plus` using `simp [*]`. This tactic instructs the term simplifier to
-use hypotheses such as `a = b` as rewriting/simplifications rules.
+use hypotheses such as `a = b` as rewriting/simplications rules.
 We use the `split` to break the nested `match` expression in the `plus` case into two cases.
 The local variables `iha` and `ihb` are the induction hypotheses for `a` and `b`.
 The modifier `←` in a term simplifier argument instructs the term simplifier to use the equation as a rewriting rule in

doc/examples/tc.lean

@@ -29,7 +29,7 @@ inductive HasType : Expr → Ty → Prop
 
 /-!
 We can easily show that if `e` has type `t₁` and type `t₂`, then `t₁` and `t₂` must be equal
-by using the `cases` tactic. This tactic creates a new subgoal for every constructor,
+by using the the `cases` tactic. This tactic creates a new subgoal for every constructor,
 and automatically discharges unreachable cases. The tactic combinator `tac₁ <;> tac₂` applies
 `tac₂` to each subgoal produced by `tac₁`. Then, the tactic `rfl` is used to close all produced
 goals using reflexivity.
@@ -82,7 +82,7 @@ theorem Expr.typeCheck_correct (h₁ : HasType e ty) (h₂ : e.typeCheck ≠ .un
 /-!
 Now, we prove that if `Expr.typeCheck e` returns `Maybe.unknown`, then forall `ty`, `HasType e ty` does not hold.
 The notation `e.typeCheck` is sugar for `Expr.typeCheck e`. Lean can infer this because we explicitly said that `e` has type `Expr`.
-The proof is by induction on `e` and case analysis. The tactic `rename_i` is used to rename "inaccessible" variables.
+The proof is by induction on `e` and case analysis. The tactic `rename_i` is used to to rename "inaccessible" variables.
 We say a variable is inaccessible if it is introduced by a tactic (e.g., `cases`) or has been shadowed by another variable introduced
 by the user. Note that the tactic `simp [typeCheck]` is applied to all goal generated by the `induction` tactic, and closes
 the cases corresponding to the constructors `Expr.nat` and `Expr.bool`.

doc/examples/widgets.lean

@@ -4,18 +4,15 @@ open Lean Widget
 /-!
 # The user-widgets system
 
-Proving and programming are inherently interactive tasks.
-Lots of mathematical objects and data structures are visual in nature.
-*User widgets* let you associate custom interactive UIs
-with sections of a Lean document.
-User widgets are rendered in the Lean infoview.
+Proving and programming are inherently interactive tasks. Lots of mathematical objects and data
+structures are visual in nature. *User widgets* let you associate custom interactive UIs with
+sections of a Lean document. User widgets are rendered in the Lean infoview.
 
 ![Rubik's cube](../images/widgets_rubiks.png)
 
 ## Trying it out
 
-To try it out, type in the following code and place your cursor over the `#widget` command.
-You can also [view this manual entry in the online editor](https://live.lean-lang.org/#url=https%3A%2F%2Fraw.githubusercontent.com%2Fleanprover%2Flean4%2Fmaster%2Fdoc%2Fexamples%2Fwidgets.lean).
+To try it out, simply type in the following code and place your cursor over the `#widget` command.
 -/
 
 @[widget_module]
@@ -24,37 +21,38 @@ def helloWidget : Widget.Module where
     import * as React from 'react';
     export default function(props) {
       const name = props.name || 'world'
-      return React.createElement('p', {}, 'Hello ' + name + '!')
+      return React.createElement('p', {}, name + '!')
     }"
 
 #widget helloWidget
 
 /-!
 If you want to dive into a full sample right away, check out
-[`Rubiks`](https://github.com/leanprover-community/ProofWidgets4/blob/main/ProofWidgets/Demos/Rubiks.lean).
-This sample uses higher-level widget components from the ProofWidgets library.
-
+[`RubiksCube`](https://github.com/leanprover/lean4-samples/blob/main/RubiksCube/).
 Below, we'll explain the system piece by piece.
 
 ⚠️ WARNING: All of the user widget APIs are **unstable** and subject to breaking changes.
 
-## Widget modules and instances
+## Widget sources and instances
 
-A [widget module](https://leanprover-community.github.io/mathlib4_docs/Lean/Widget/UserWidget.html#Lean.Widget.Module)
-is a valid JavaScript [ESModule](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules)
-that can execute in the Lean infoview.
-Most widget modules export a [React component](https://reactjs.org/docs/components-and-props.html)
-as the piece of user interface to be rendered.
-To access React, the module can use `import * as React from 'react'`.
-Our first example of a widget module is `helloWidget` above.
-Widget modules must be registered with the `@[widget_module]` attribute.
+A *widget source* is a valid JavaScript [ESModule](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules)
+which exports a [React component](https://reactjs.org/docs/components-and-props.html). To access
+React, the module must use `import * as React from 'react'`. Our first example of a widget source
+is of course the value of `helloWidget.javascript`.
 
-A [widget instance](https://leanprover-community.github.io/mathlib4_docs/Lean/Widget/Types.html#Lean.Widget.WidgetInstance)
-is then the identifier of a widget module (e.g. `` `helloWidget ``)
-bundled with a value for its props.
-This value is passed as the argument to the React component.
-In our first invocation of `#widget`, we set it to `.null`.
-Try out what happens when you type in:
+We can register a widget source with the `@[widget]` attribute, giving it a friendlier name
+in the `name` field. This is bundled together in a `UserWidgetDefinition`.
+
+A *widget instance* is then the identifier of a `UserWidgetDefinition` (so `` `helloWidget ``,
+not `"Hello"`) associated with a range of positions in the Lean source code. Widget instances
+are stored in the *infotree* in the same manner as other information about the source file
+such as the type of every expression. In our example, the `#widget` command stores a widget instance
+with the entire line as its range. We can think of a widget instance as an instruction for the
+infoview: "when the user places their cursor here, please render the following widget".
+
+Every widget instance also contains a `props : Json` value. This value is passed as an argument
+to the React component. In our first invocation of `#widget`, we set it to `.null`. Try out what
+happens when you type in:
 -/
 
 structure HelloWidgetProps where
@@ -64,37 +62,21 @@ structure HelloWidgetProps where
 #widget helloWidget with { name? := "<your name here>" : HelloWidgetProps }
 
 /-!
-Under the hood, widget instances are associated with a range of positions in the source file.
-Widget instances are stored in the *infotree*
-in the same manner as other information about the source file
-such as the type of every expression.
-In our example, the `#widget` command stores a widget instance
-with the entire line as its range.
-One can think of the infotree entry as an instruction for the infoview:
-"when the user places their cursor here, please render the following widget".
--/
+💡 NOTE: The RPC system presented below does not depend on JavaScript. However the primary use case
+is the web-based infoview in VSCode.
 
-/-!
 ## Querying the Lean server
 
-💡 NOTE: The RPC system presented below does not depend on JavaScript.
-However, the primary use case is the web-based infoview in VSCode.
+Besides enabling us to create cool client-side visualizations, user widgets come with the ability
+to communicate with the Lean server. Thanks to this, they have the same metaprogramming capabilities
+as custom elaborators or the tactic framework. To see this in action, let's implement a `#check`
+command as a web input form. This example assumes some familiarity with React.
 
-Besides enabling us to create cool client-side visualizations,
-user widgets have the ability to communicate with the Lean server.
-Thanks to this, they have the same metaprogramming capabilities
-as custom elaborators or the tactic framework.
-To see this in action, let's implement a `#check` command as a web input form.
-This example assumes some familiarity with React.
-
-The first thing we'll need is to create an *RPC method*.
-Meaning "Remote Procedure Call",this is a Lean function callable from widget code
-(possibly remotely over the internet).
+The first thing we'll need is to create an *RPC method*. Meaning "Remote Procedure Call", this
+is basically a Lean function callable from widget code (possibly remotely over the internet).
 Our method will take in the `name : Name` of a constant in the environment and return its type.
-By convention, we represent the input data as a `structure`.
-Since it will be sent over from JavaScript,
-we need `FromJson` and `ToJson` instance.
-We'll see why the position field is needed later.
+By convention, we represent the input data as a `structure`. Since it will be sent over from JavaScript,
+we need `FromJson` and `ToJson`. We'll see below why the position field is needed.
 -/
 
 structure GetTypeParams where
@@ -105,33 +87,25 @@ structure GetTypeParams where
   deriving FromJson, ToJson
 
 /-!
-After its argument structure, we define the `getType` method.
-RPCs method execute in the `RequestM` monad and must return a `RequestTask α`
-where `α` is the "actual" return type.
-The `Task` is so that requests can be handled concurrently.
-As a first guess, we'd use `Expr` as `α`.
-However, expressions in general can be large objects
-which depend on an `Environment` and `LocalContext`.
-Thus we cannot directly serialize an `Expr` and send it to JavaScript.
-Instead, there are two options:
+After its arguments, we define the `getType` method. Every RPC method executes in the `RequestM`
+monad and must return a `RequestTask α` where `α` is its "actual" return type. The `Task` is so
+that requests can be handled concurrently. A first guess for `α` might be `Expr`. However,
+expressions in general can be large objects which depend on an `Environment` and `LocalContext`.
+Thus we cannot directly serialize an `Expr` and send it to the widget. Instead, there are two
+options:
+- One is to send a *reference* which points to an object residing on the server. From JavaScript's
+  point of view, references are entirely opaque, but they can be sent back to other RPC methods for
+  further processing.
+- Two is to pretty-print the expression and send its textual representation called `CodeWithInfos`.
+  This representation contains extra data which the infoview uses for interactivity. We take this
+  strategy here.
 
-- One is to send a *reference* which points to an object residing on the server.
-  From JavaScript's point of view, references are entirely opaque,
-  but they can be sent back to other RPC methods for further processing.
-- The other is to pretty-print the expression and send its textual representation called `CodeWithInfos`.
-  This representation contains extra data which the infoview uses for interactivity.
-  We take this strategy here.
-
-RPC methods execute in the context of a file,
-but not of any particular `Environment`,
-so they don't know about the available `def`initions and `theorem`s.
-Thus, we need to pass in a position at which we want to use the local `Environment`.
-This is why we store it in `GetTypeParams`.
-The `withWaitFindSnapAtPos` method launches a concurrent computation
-whose job is to find such an `Environment` for us,
-in the form of a `snap : Snapshot`.
-With this in hand, we can call `MetaM` procedures
-to find out the type of `name` and pretty-print it.
+RPC methods execute in the context of a file, but not any particular `Environment` so they don't
+know about the available `def`initions and `theorem`s. Thus, we need to pass in a position at which
+we want to use the local `Environment`. This is why we store it in `GetTypeParams`. The `withWaitFindSnapAtPos`
+method launches a concurrent computation whose job is to find such an `Environment` and a bit
+more information for us, in the form of a `snap : Snapshot`. With this in hand, we can call
+`MetaM` procedures to find out the type of `name` and pretty-print it.
 -/
 
 open Server RequestM in
@@ -147,22 +121,18 @@ def getType (params : GetTypeParams) : RequestM (RequestTask CodeWithInfos) :=
 /-!
 ## Using infoview components
 
-Now that we have all we need on the server side, let's write the widget module.
-By importing `@leanprover/infoview`, widgets can render UI components used to implement the infoview itself.
-For example, the `<InteractiveCode>` component displays expressions
-with `term : type` tooltips as seen in the goal view.
-We will use it to implement our custom `#check` display.
+Now that we have all we need on the server side, let's write the widget source. By importing
+`@leanprover/infoview`, widgets can render UI components used to implement the infoview itself.
+For example, the `<InteractiveCode>` component displays expressions with `term : type` tooltips
+as seen in the goal view. We will use it to implement our custom `#check` display.
 
 ⚠️ WARNING: Like the other widget APIs, the infoview JS API is **unstable** and subject to breaking changes.
 
-The code below demonstrates useful parts of the API.
-To make RPC method calls, we invoke the `useRpcSession` hook.
-The `useAsync` helper packs the results of an RPC call into an `AsyncState` structure
-which indicates whether the call has resolved successfully,
-has returned an error, or is still in-flight.
-Based on this we either display an `InteractiveCode` component with the result,
-`mapRpcError` the error in order to turn it into a readable message,
-or show a `Loading..` message, respectively.
+The code below demonstrates useful parts of the API. To make RPC method calls, we use the `RpcContext`.
+The `useAsync` helper packs the results of a call into an `AsyncState` structure which indicates
+whether the call has resolved successfully, has returned an error, or is still in-flight. Based
+on this we either display an `InteractiveCode` with the type, `mapRpcError` the error in order
+to turn it into a readable message, or show a `Loading..` message, respectively.
 -/
 
 @[widget_module]
@@ -170,10 +140,10 @@ def checkWidget : Widget.Module where
   javascript := "
 import * as React from 'react';
 const e = React.createElement;
-import { useRpcSession, InteractiveCode, useAsync, mapRpcError } from '@leanprover/infoview';
+import { RpcContext, InteractiveCode, useAsync, mapRpcError } from '@leanprover/infoview';
 
 export default function(props) {
-  const rs = useRpcSession()
+  const rs = React.useContext(RpcContext)
   const [name, setName] = React.useState('getType')
 
   const st = useAsync(() =>
@@ -189,7 +159,7 @@ export default function(props) {
 "
 
 /-!
-We can now try out the widget.
+Finally we can try out the widget.
 -/
 
 #widget checkWidget
@@ -199,31 +169,30 @@ We can now try out the widget.
 
 ## Building widget sources
 
-While typing JavaScript inline is fine for a simple example,
-for real developments we want to use packages from NPM, a proper build system, and JSX.
-Thus, most actual widget sources are built with Lake and NPM.
-They consist of multiple files and may import libraries which don't work as ESModules by default.
-On the other hand a widget module must be a single, self-contained ESModule in the form of a string.
-Readers familiar with web development may already have guessed that to obtain such a string, we need a *bundler*.
-Two popular choices are [`rollup.js`](https://rollupjs.org/guide/en/)
-and [`esbuild`](https://esbuild.github.io/).
-If we go with `rollup.js`, to make a widget work with the infoview we need to:
+While typing JavaScript inline is fine for a simple example, for real developments we want to use
+packages from NPM, a proper build system, and JSX. Thus, most actual widget sources are built with
+Lake and NPM. They consist of multiple files and may import libraries which don't work as ESModules
+by default. On the other hand a widget source must be a single, self-contained ESModule in the form
+of a string. Readers familiar with web development may already have guessed that to obtain such a
+string, we need a *bundler*. Two popular choices are [`rollup.js`](https://rollupjs.org/guide/en/)
+and [`esbuild`](https://esbuild.github.io/). If we go with `rollup.js`, to make a widget work with
+the infoview we need to:
 - Set [`output.format`](https://rollupjs.org/guide/en/#outputformat) to `'es'`.
 - [Externalize](https://rollupjs.org/guide/en/#external) `react`, `react-dom`, `@leanprover/infoview`.
   These libraries are already loaded by the infoview so they should not be bundled.
 
-ProofWidgets provides a working `rollup.js` build configuration in
-[rollup.config.js](https://github.com/leanprover-community/ProofWidgets4/blob/main/widget/rollup.config.js).
+In the RubiksCube sample, we provide a working `rollup.js` build configuration in
+[rollup.config.js](https://github.com/leanprover/lean4-samples/blob/main/RubiksCube/widget/rollup.config.js).
 
 ## Inserting text
 
-Besides making RPC calls, widgets can instruct the editor to carry out certain actions.
-We can insert text, copy text to the clipboard, or highlight a certain location in the document.
-To do this, use the `EditorContext` React context.
-This will return an `EditorConnection`
-whose `api` field contains a number of methods that interact with the editor.
+We can also instruct the editor to insert text, copy text to the clipboard, or
+reveal a certain location in the document.
+To do this, use the `React.useContext(EditorContext)` React context.
+This will return an `EditorConnection` whose `api` field contains a number of methods to
+interact with the text editor.
 
-The full API can be viewed [here](https://github.com/leanprover/vscode-lean4/blob/master/lean4-infoview-api/src/infoviewApi.ts#L52).
+You can see the full API for this [here](https://github.com/leanprover/vscode-lean4/blob/master/lean4-infoview-api/src/infoviewApi.ts#L52)
 -/
 
 @[widget_module]
@@ -243,4 +212,6 @@ export default function(props) {
 }
 "
 
+/-! Finally, we can try this out: -/
+
 #widget insertTextWidget

doc/expressions.md

@@ -396,7 +396,7 @@ Every expression in Lean has a natural computational interpretation, unless it i
 
 * *β-reduction* : An expression ``(λ x, t) s`` β-reduces to ``t[s/x]``, that is, the result of replacing ``x`` by ``s`` in ``t``.
 * *ζ-reduction* : An expression ``let x := s in t`` ζ-reduces to ``t[s/x]``.
-* *δ-reduction* : If ``c`` is a defined constant with definition ``t``, then ``c`` δ-reduces to ``t``.
+* *δ-reduction* : If ``c`` is a defined constant with definition ``t``, then ``c`` δ-reduces to to ``t``.
 * *ι-reduction* : When a function defined by recursion on an inductive type is applied to an element given by an explicit constructor, the result ι-reduces to the specified function value, as described in [Inductive Types](inductive.md).
 
 The reduction relation is transitive, which is to say, is ``s`` reduces to ``s'`` and ``t`` reduces to ``t'``, then ``s t`` reduces to ``s' t'``, ``λ x, s`` reduces to ``λ x, s'``, and so on. If ``s`` and ``t`` reduce to a common term, they are said to be *definitionally equal*. Definitional equality is defined to be the smallest equivalence relation that satisfies all these properties and also includes α-equivalence and the following two relations:

doc/flake.lock

@@ -18,15 +18,12 @@
       }
     },
     "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
       "locked": {
-        "lastModified": 1710146030,
-        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "lastModified": 1656928814,
+        "narHash": "sha256-RIFfgBuKz6Hp89yRr7+NR5tzIAbn52h8vT6vXkYjZoM=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "rev": "7e2a3b3dfd9af950a856d66b0a7d01e3c18aa249",
         "type": "github"
       },
       "original": {
@@ -38,12 +35,13 @@
     "lean": {
       "inputs": {
         "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs",
-        "nixpkgs-old": "nixpkgs-old"
+        "lean4-mode": "lean4-mode",
+        "nix": "nix",
+        "nixpkgs": "nixpkgs_2"
       },
       "locked": {
         "lastModified": 0,
-        "narHash": "sha256-saRAtQ6VautVXKDw1XH35qwP0KEBKTKZbg/TRa4N9Vw=",
+        "narHash": "sha256-YnYbmG0oou1Q/GE4JbMNb8/yqUVXBPIvcdQQJHBqtPk=",
         "path": "../.",
         "type": "path"
       },
@@ -52,6 +50,22 @@
         "type": "path"
       }
     },
+    "lean4-mode": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1659020985,
+        "narHash": "sha256-+dRaXB7uvN/weSZiKcfSKWhcdJVNg9Vg8k0pJkDNjpc=",
+        "owner": "leanprover",
+        "repo": "lean4-mode",
+        "rev": "37d5c99b7b29c80ab78321edd6773200deb0bca6",
+        "type": "github"
+      },
+      "original": {
+        "owner": "leanprover",
+        "repo": "lean4-mode",
+        "type": "github"
+      }
+    },
     "leanInk": {
       "flake": false,
       "locked": {
@@ -69,6 +83,22 @@
         "type": "github"
       }
     },
+    "lowdown-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1633514407,
+        "narHash": "sha256-Dw32tiMjdK9t3ETl5fzGrutQTzh2rufgZV4A/BbxuD4=",
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "rev": "d2c2b44ff6c27b936ec27358a2653caaef8f73b8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "type": "github"
+      }
+    },
     "mdBook": {
       "flake": false,
       "locked": {
@@ -85,13 +115,65 @@
         "type": "github"
       }
     },
+    "nix": {
+      "inputs": {
+        "lowdown-src": "lowdown-src",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-regression": "nixpkgs-regression"
+      },
+      "locked": {
+        "lastModified": 1657097207,
+        "narHash": "sha256-SmeGmjWM3fEed3kQjqIAO8VpGmkC2sL1aPE7kKpK650=",
+        "owner": "NixOS",
+        "repo": "nix",
+        "rev": "f6316b49a0c37172bca87ede6ea8144d7d89832f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nix",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1710889954,
-        "narHash": "sha256-Pr6F5Pmd7JnNEMHHmspZ0qVqIBVxyZ13ik1pJtm2QXk=",
+        "lastModified": 1653988320,
+        "narHash": "sha256-ZaqFFsSDipZ6KVqriwM34T739+KLYJvNmCWzErjAg7c=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "7872526e9c5332274ea5932a0c3270d6e4724f3b",
+        "rev": "2fa57ed190fd6c7c746319444f34b5917666e5c1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-22.05-small",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-regression": {
+      "locked": {
+        "lastModified": 1643052045,
+        "narHash": "sha256-uGJ0VXIhWKGXxkeNnq4TvV3CIOkUJ3PAoLZ3HMzNVMw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1657208011,
+        "narHash": "sha256-BlIFwopAykvdy1DYayEkj6ZZdkn+cVgPNX98QVLc0jM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2770cc0b1e8faa0e20eb2c6aea64c256a706d4f2",
         "type": "github"
       },
       "original": {
@@ -101,23 +183,6 @@
         "type": "github"
       }
     },
-    "nixpkgs-old": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1581379743,
-        "narHash": "sha256-i1XCn9rKuLjvCdu2UeXKzGLF6IuQePQKFt4hEKRU5oc=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "34c7eb7545d155cc5b6f499b23a7cb1c96ab4d59",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-19.03",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "root": {
       "inputs": {
         "alectryon": "alectryon",
@@ -129,21 +194,6 @@
         "leanInk": "leanInk",
         "mdBook": "mdBook"
       }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
     }
   },
   "root": "root",

doc/flake.nix

@@ -17,7 +17,7 @@
   };
 
   outputs = inputs@{ self, ... }: inputs.flake-utils.lib.eachDefaultSystem (system:
-    with inputs.lean.packages.${system}.deprecated; with nixpkgs;
+    with inputs.lean.packages.${system}; with nixpkgs;
     let
       doc-src = lib.sourceByRegex ../. ["doc.*" "tests(/lean(/beginEndAsMacro.lean)?)?"];
     in {
@@ -44,6 +44,21 @@
           mdbook build -d $out
         '';
       };
+      # We use a separate derivation instead of `checkPhase` so we can push it but not `doc` to the binary cache
+      test = stdenv.mkDerivation {
+        name ="lean-doc-test";
+        src = doc-src;
+        buildInputs = [ lean-mdbook stage1.Lean.lean-package strace ];
+        patchPhase = ''
+          cd doc
+          patchShebangs test
+        '';
+        buildPhase = ''
+          mdbook test
+          touch $out
+        '';
+        dontInstall = true;
+      };
       leanInk = (buildLeanPackage {
         name = "Main";
         src = inputs.leanInk;

doc/make/index.md

@@ -1,6 +1,6 @@
-These are instructions to set up a working development environment for those who wish to make changes to Lean itself. It is part of the [Development Guide](../dev/index.md).
+These are instructions to set up a working development environment for those who wish to make changes to Lean itself. It is part of the [Development Guide](doc/dev/index.md).
 
-We strongly suggest that new users instead follow the [Quickstart](../quickstart.md) to get started using Lean, since this sets up an environment that can automatically manage multiple Lean toolchain versions, which is necessary when working within the Lean ecosystem.
+We strongly suggest that new users instead follow the [Quickstart](doc/quickstart.md) to get started using Lean, since this sets up an environment that can automatically manage multiple Lean toolchain versions, which is necessary when working within the Lean ecosystem.
 
 Requirements
 ------------
@@ -8,7 +8,6 @@ Requirements
 - C++14 compatible compiler
 - [CMake](http://www.cmake.org)
 - [GMP (GNU multiprecision library)](http://gmplib.org/)
-- [LibUV](https://libuv.org/)
 
 Platform-Specific Setup
 -----------------------
@@ -28,9 +27,9 @@ Setting up a basic parallelized release build:
 git clone https://github.com/leanprover/lean4
 cd lean4
 cmake --preset release
-make -C build/release -j$(nproc || sysctl -n hw.logicalcpu)
+make -C build/release -j$(nproc)  # see below for macOS
 ```
-You can replace `$(nproc || sysctl -n hw.logicalcpu)` with the desired parallelism amount.
+You can replace `$(nproc)`, which is not available on macOS and some alternative shells, with the desired parallelism amount.
 
 The above commands will compile the Lean library and binaries into the
 `stage1` subfolder; see below for details.

doc/make/msys2.md

@@ -15,24 +15,17 @@ Mode](https://docs.microsoft.com/en-us/windows/apps/get-started/enable-your-devi
 which will allow Lean to create symlinks that e.g. enable go-to-definition in
 the stdlib.
 
-## Installing the Windows SDK
-
-Install the Windows SDK from [Microsoft](https://developer.microsoft.com/en-us/windows/downloads/windows-sdk/).
-The oldest supported version is 10.0.18362.0. If you installed the Windows SDK to the default location,
-then there should be a directory with the version number at `C:\Program Files (x86)\Windows Kits\10\Include`.
-If there are multiple directories, only the highest version number matters.
-
 ## Installing dependencies
 
 [The official webpage of MSYS2][msys2] provides one-click installers.
-Once installed, you should run the "MSYS2 CLANG64" shell from the start menu (the one that runs `clang64.exe`).
-Do not run "MSYS2 MSYS" or "MSYS2 MINGW64" instead!
-MSYS2 has a package management system, [pacman][pacman].
+Once installed, you should run the "MSYS2 MinGW 64-bit shell" from the start menu (the one that runs `mingw64.exe`).
+Do not run "MSYS2 MSYS" instead!
+MSYS2 has a package management system, [pacman][pacman], which is used in Arch Linux.
 
 Here are the commands to install all dependencies needed to compile Lean on your machine.
 
 ```bash
-pacman -S make python mingw-w64-clang-x86_64-cmake mingw-w64-clang-x86_64-clang mingw-w64-clang-x86_64-ccache mingw-w64-clang-x86_64-libuv mingw-w64-clang-x86_64-gmp git unzip diffutils binutils
+pacman -S make python mingw-w64-x86_64-cmake mingw-w64-x86_64-clang mingw-w64-x86_64-ccache git unzip diffutils binutils
 ```
 
 You should now be able to run these commands:
@@ -68,9 +61,9 @@ If you want a version that can run independently of your MSYS install
 then you need to copy the following dependent DLL's from where ever
 they are installed in your MSYS setup:
 
-- libc++.dll
+- libgcc_s_seh-1.dll
+- libstdc++-6.dll
 - libgmp-10.dll
-- libuv-1.dll
 - libwinpthread-1.dll
 
 The following linux command will do that:
@@ -88,6 +81,6 @@ version clang to your path.
 
 **-bash: gcc: command not found**
 
-Make sure `/clang64/bin` is in your PATH environment.  If it is not then
-check you launched the MSYS2 CLANG64 shell from the start menu.
-(The one that runs `clang64.exe`).
+Make sure `/mingw64/bin` is in your PATH environment.  If it is not then
+check you launched the MSYS2 MinGW 64-bit shell from the start menu.
+(The one that runs `mingw64.exe`).

doc/make/osx-10.9.md

@@ -32,16 +32,15 @@ following to use `g++`.
 cmake -DCMAKE_CXX_COMPILER=g++ ...
 ```
 
-## Required Packages: CMake, GMP, libuv
+## Required Packages: CMake, GMP
 
 ```bash
 brew install cmake
 brew install gmp
-brew install libuv
 ```
 
 ## Recommended Packages: CCache
 
 ```bash
 brew install ccache
-```
+```

doc/make/ubuntu.md

@@ -8,5 +8,5 @@ follow the [generic build instructions](index.md).
 ## Basic packages
 
 ```bash
-sudo apt-get install git libgmp-dev libuv1-dev cmake ccache clang
+sudo apt-get install git libgmp-dev cmake ccache clang
 ```

doc/monads/applicatives.lean

@@ -138,8 +138,8 @@ definition:
 
 -/
 instance : Applicative List where
-  pure := List.singleton
-  seq f x := List.flatMap f fun y => Functor.map y (x ())
+  pure := List.pure
+  seq f x := List.bind f fun y => Functor.map y (x ())
 /-!
 
 Notice you can now sequence a _list_ of functions and a _list_ of items.

doc/monads/laws.lean

@@ -128,8 +128,8 @@ Applying the identity function through an applicative structure should not chang
 values or structure.  For example:
 -/
 instance : Applicative List where
-  pure := List.singleton
-  seq f x := List.flatMap f fun y => Functor.map y (x ())
+  pure := List.pure
+  seq f x := List.bind f fun y => Functor.map y (x ())
 
 #eval pure id <*> [1, 2, 3]  -- [1, 2, 3]
 /-!
@@ -171,7 +171,7 @@ of data contained in the container resulting in a new container that has the sam
 
 `u <*> pure y = pure (. y) <*> u`.
 
-This law is a little more complicated, so don't sweat it too much. It states that the order that
+This law is is a little more complicated, so don't sweat it too much. It states that the order that
 you wrap things shouldn't matter. One the left, you apply any applicative `u` over a pure wrapped
 object. On the right, you first wrap a function applying the object as an argument. Note that `(·
 y)` is short hand for: `fun f => f y`. Then you apply this to the first applicative `u`. These
@@ -235,8 +235,8 @@ structure or its values.
 Left identity is `x >>= pure = x` and is demonstrated by the following examples on a monadic `List`:
 -/
 instance : Monad List  where
-  pure := List.singleton
-  bind := List.flatMap
+  pure := List.pure
+  bind := List.bind
 
 def a := ["apple", "orange"]
 

doc/monads/monads.lean

@@ -192,8 +192,8 @@ implementation of `pure` and `bind`.
 
 -/
 instance : Monad List  where
-  pure := List.singleton
-  bind := List.flatMap
+  pure := List.pure
+  bind := List.bind
 /-!
 
 Like you saw with the applicative `seq` operator, the `bind` operator applies the given function

doc/quickstart.md

@@ -5,19 +5,14 @@ See [Setup](./setup.md) for supported platforms and other ways to set up Lean 4.
 
 1. Install [VS Code](https://code.visualstudio.com/).
 
-1. Launch VS Code and install the `Lean 4` extension by clicking on the 'Extensions' sidebar entry and searching for 'Lean 4'.
+1. Launch VS Code and install the `lean4` extension by clicking on the "Extensions" sidebar entry and searching for "lean4".
 
-   ![installing the vscode-lean4 extension](images/code-ext.png)
+    ![installing the vscode-lean4 extension](images/code-ext.png)
 
-1. Open the Lean 4 setup guide by creating a new text file using 'File > New Text File' (`Ctrl+N` / `Cmd+N`), clicking on the ∀-symbol in the top right and selecting 'Documentation… > Docs: Show Setup Guide'.
+1. Open the Lean 4 setup guide by creating a new text file using "File > New Text File" (`Ctrl+N`), clicking on the ∀-symbol in the top right and selecting "Documentation… > Setup: Show Setup Guide".
 
-   ![show setup guide](images/show-setup-guide.png)
+    ![show setup guide](images/show-setup-guide.png)
 
-1. Follow the Lean 4 setup guide. It will:
+1. Follow the Lean 4 setup guide. It will walk you through learning resources for Lean 4, teach you how to set up Lean's dependencies on your platform, install Lean 4 for you at the click of a button and help you set up your first project.
 
-   - walk you through learning resources for Lean,
-   - teach you how to set up Lean's dependencies on your platform,
-   - install Lean 4 for you at the click of a button,
-   - help you set up your first project.
-
-   ![setup guide](images/setup_guide.png)
+    ![setup guide](images/setup_guide.png)

doc/setup.md

@@ -7,7 +7,7 @@ Platforms built & tested by our CI, available as binary releases via elan (see b
 * x86-64 Linux with glibc 2.27+
 * x86-64 macOS 10.15+
 * aarch64 (Apple Silicon) macOS 10.15+
-* x86-64 Windows 11 (any version), Windows 10 (version 1903 or higher), Windows Server 2022
+* x86-64 Windows 10+
 
 ### Tier 2
 

flake.lock

@@ -1,5 +1,21 @@
 {
   "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1673956053,
+        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -18,35 +34,72 @@
         "type": "github"
       }
     },
-    "nixpkgs": {
+    "lean4-mode": {
+      "flake": false,
       "locked": {
-        "lastModified": 1710889954,
-        "narHash": "sha256-Pr6F5Pmd7JnNEMHHmspZ0qVqIBVxyZ13ik1pJtm2QXk=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "7872526e9c5332274ea5932a0c3270d6e4724f3b",
+        "lastModified": 1709737301,
+        "narHash": "sha256-uT9JN2kLNKJK9c/S/WxLjiHmwijq49EgLb+gJUSDpz0=",
+        "owner": "leanprover",
+        "repo": "lean4-mode",
+        "rev": "f1f24c15134dee3754b82c9d9924866fe6bc6b9f",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
-        "ref": "nixpkgs-unstable",
-        "repo": "nixpkgs",
+        "owner": "leanprover",
+        "repo": "lean4-mode",
         "type": "github"
       }
     },
-    "nixpkgs-cadical": {
+    "libgit2": {
+      "flake": false,
       "locked": {
-        "lastModified": 1722221733,
-        "narHash": "sha256-sga9SrrPb+pQJxG1ttJfMPheZvDOxApFfwXCFO0H9xw=",
+        "lastModified": 1697646580,
+        "narHash": "sha256-oX4Z3S9WtJlwvj0uH9HlYcWv+x1hqp8mhXl7HsLu2f0=",
+        "owner": "libgit2",
+        "repo": "libgit2",
+        "rev": "45fd9ed7ae1a9b74b957ef4f337bc3c8b3df01b5",
+        "type": "github"
+      },
+      "original": {
+        "owner": "libgit2",
+        "repo": "libgit2",
+        "type": "github"
+      }
+    },
+    "nix": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "libgit2": "libgit2",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-regression": "nixpkgs-regression"
+      },
+      "locked": {
+        "lastModified": 1711102798,
+        "narHash": "sha256-CXOIJr8byjolqG7eqCLa+Wfi7rah62VmLoqSXENaZnw=",
         "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "12bf09802d77264e441f48e25459c10c93eada2e",
+        "repo": "nix",
+        "rev": "a22328066416650471c3545b0b138669ea212ab4",
         "type": "github"
       },
       "original": {
+        "owner": "NixOS",
+        "repo": "nix",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1709083642,
+        "narHash": "sha256-7kkJQd4rZ+vFrzWu8sTRtta5D1kBG0LSRYAfhtmMlSo=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "12bf09802d77264e441f48e25459c10c93eada2e",
+        "rev": "b550fe4b4776908ac2a861124307045f8e717c8e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "release-23.11",
+        "repo": "nixpkgs",
         "type": "github"
       }
     },
@@ -67,11 +120,44 @@
         "type": "github"
       }
     },
+    "nixpkgs-regression": {
+      "locked": {
+        "lastModified": 1643052045,
+        "narHash": "sha256-uGJ0VXIhWKGXxkeNnq4TvV3CIOkUJ3PAoLZ3HMzNVMw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1710889954,
+        "narHash": "sha256-Pr6F5Pmd7JnNEMHHmspZ0qVqIBVxyZ13ik1pJtm2QXk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "7872526e9c5332274ea5932a0c3270d6e4724f3b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs",
-        "nixpkgs-cadical": "nixpkgs-cadical",
+        "lean4-mode": "lean4-mode",
+        "nix": "nix",
+        "nixpkgs": "nixpkgs_2",
         "nixpkgs-old": "nixpkgs-old"
       }
     },

flake.nix

@@ -1,36 +1,48 @@
 {
-  description = "Lean development flake. Not intended for end users.";
+  description = "Lean interactive theorem prover";
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
   # old nixpkgs used for portable release with older glibc (2.27)
   inputs.nixpkgs-old.url = "github:NixOS/nixpkgs/nixos-19.03";
   inputs.nixpkgs-old.flake = false;
-  # for cadical 1.9.5; sync with CMakeLists.txt
-  inputs.nixpkgs-cadical.url = "github:NixOS/nixpkgs/12bf09802d77264e441f48e25459c10c93eada2e";
   inputs.flake-utils.url = "github:numtide/flake-utils";
+  inputs.nix.url = "github:NixOS/nix";
+  inputs.lean4-mode = {
+    url = "github:leanprover/lean4-mode";
+    flake = false;
+  };
+  # used *only* by `stage0-from-input` below
+  #inputs.lean-stage0 = {
+  #  url = github:leanprover/lean4;
+  #  inputs.nixpkgs.follows = "nixpkgs";
+  #  inputs.flake-utils.follows = "flake-utils";
+  #  inputs.nix.follows = "nix";
+  #  inputs.lean4-mode.follows = "lean4-mode";
+  #};
 
-  outputs = { self, nixpkgs, nixpkgs-old, flake-utils, ... }@inputs: flake-utils.lib.eachDefaultSystem (system:
+  outputs = { self, nixpkgs, nixpkgs-old, flake-utils, nix, lean4-mode, ... }@inputs: flake-utils.lib.eachDefaultSystem (system:
     let
-      pkgs = import nixpkgs { inherit system; };
+      pkgs = import nixpkgs {
+        inherit system;
+        # for `vscode-with-extensions`
+        config.allowUnfree = true;
+      };
       # An old nixpkgs for creating releases with an old glibc
       pkgsDist-old = import nixpkgs-old { inherit system; };
       # An old nixpkgs for creating releases with an old glibc
       pkgsDist-old-aarch = import nixpkgs-old { localSystem.config = "aarch64-unknown-linux-gnu"; };
-      pkgsCadical = import inputs.nixpkgs-cadical { inherit system; };
-      cadical = if pkgs.stdenv.isLinux then
-        # use statically-linked cadical on Linux to avoid glibc versioning troubles
-        pkgsCadical.pkgsStatic.cadical.overrideAttrs { doCheck = false; }
-      else pkgsCadical.cadical;
 
-      lean-packages = pkgs.callPackage (./nix/packages.nix) { src = ./.; };
+      lean-packages = pkgs.callPackage (./nix/packages.nix) { src = ./.; inherit nix lean4-mode; };
 
       devShellWithDist = pkgsDist: pkgs.mkShell.override {
           stdenv = pkgs.overrideCC pkgs.stdenv lean-packages.llvmPackages.clang;
         } ({
           buildInputs = with pkgs; [
-            cmake gmp libuv ccache cadical
+            cmake gmp ccache
             lean-packages.llvmPackages.llvm  # llvm-symbolizer for asan/lsan
             gdb
+            # TODO: only add when proven to not affect the flakification
+            #pkgs.python3
             tree  # for CI
           ];
           # https://github.com/NixOS/nixpkgs/issues/60919
@@ -38,24 +50,7 @@
           # more convenient `ctest` output
           CTEST_OUTPUT_ON_FAILURE = 1;
         } // pkgs.lib.optionalAttrs pkgs.stdenv.isLinux {
-          GMP = (pkgsDist.gmp.override { withStatic = true; }).overrideAttrs (attrs:
-            pkgs.lib.optionalAttrs (pkgs.stdenv.system == "aarch64-linux") {
-              # would need additional linking setup on Linux aarch64, we don't use it anywhere else either
-              hardeningDisable = [ "stackprotector" ];
-            });
-          LIBUV = pkgsDist.libuv.overrideAttrs (attrs: {
-            configureFlags = ["--enable-static"];
-            hardeningDisable = [ "stackprotector" ];
-            # Sync version with CMakeLists.txt
-            version = "1.48.0";
-            src = pkgs.fetchFromGitHub {
-              owner = "libuv";
-              repo = "libuv";
-              rev = "v1.48.0";
-              sha256 = "100nj16fg8922qg4m2hdjh62zv4p32wyrllsvqr659hdhjc03bsk";
-            };
-            doCheck = false;
-          });
+          GMP = pkgsDist.gmp.override { withStatic = true; };
           GLIBC = pkgsDist.glibc;
           GLIBC_DEV = pkgsDist.glibc.dev;
           GCC_LIB = pkgsDist.gcc.cc.lib;
@@ -63,15 +58,41 @@
           GDB = pkgsDist.gdb;
         });
     in {
-      packages = {
-        # to be removed when Nix CI is not needed anymore
-        inherit (lean-packages) cacheRoots test update-stage0-commit ciShell;
-        deprecated = lean-packages;
+      packages = lean-packages // rec {
+        debug = lean-packages.override { debug = true; };
+        stage0debug = lean-packages.override { stage0debug = true; };
+        asan = lean-packages.override { extraCMakeFlags = [ "-DLEAN_EXTRA_CXX_FLAGS=-fsanitize=address" "-DLEANC_EXTRA_FLAGS=-fsanitize=address" "-DSMALL_ALLOCATOR=OFF" "-DSYMBOLIC=OFF" ]; };
+        asandebug = asan.override { debug = true; };
+        tsan = lean-packages.override {
+          extraCMakeFlags = [ "-DLEAN_EXTRA_CXX_FLAGS=-fsanitize=thread" "-DLEANC_EXTRA_FLAGS=-fsanitize=thread" "-DCOMPRESSED_OBJECT_HEADER=OFF" ];
+          stage0 = (lean-packages.override {
+            # Compressed headers currently trigger data race reports in tsan.
+            # Turn them off for stage 0 as well so stage 1 can read its own stdlib.
+            extraCMakeFlags = [ "-DCOMPRESSED_OBJECT_HEADER=OFF" ];
+          }).stage1;
+        };
+        tsandebug = tsan.override { debug = true; };
+        stage0-from-input = lean-packages.override {
+          stage0 = pkgs.writeShellScriptBin "lean" ''
+            exec ${inputs.lean-stage0.packages.${system}.lean}/bin/lean -Dinterpreter.prefer_native=false "$@"
+          '';
+        };
+        inherit self;
       };
+      defaultPackage = lean-packages.lean-all;
 
       # The default development shell for working on lean itself
       devShells.default = devShellWithDist pkgs;
       devShells.oldGlibc = devShellWithDist pkgsDist-old;
       devShells.oldGlibcAArch = devShellWithDist pkgsDist-old-aarch;
-    });
+
+      checks.lean = lean-packages.test;
+    }) // rec {
+      templates.pkg = {
+        path = ./nix/templates/pkg;
+        description = "A custom Lean package";
+      };
+
+      defaultTemplate = templates.pkg;
+    };
 }

nix/bootstrap.nix

@@ -1,13 +1,13 @@
 { src, debug ? false, stage0debug ? false, extraCMakeFlags ? [],
-  stdenv, lib, cmake, gmp, libuv, cadical, git, gnumake, bash, buildLeanPackage, writeShellScriptBin, runCommand, symlinkJoin, lndir, perl, gnused, darwin, llvmPackages, linkFarmFromDrvs,
+  stdenv, lib, cmake, gmp, git, gnumake, bash, buildLeanPackage, writeShellScriptBin, runCommand, symlinkJoin, lndir, perl, gnused, darwin, llvmPackages, linkFarmFromDrvs,
   ... } @ args:
 with builtins;
-lib.warn "The Nix-based build is deprecated" rec {
+rec {
   inherit stdenv;
   sourceByRegex = p: rs: lib.sourceByRegex p (map (r: "(/src/)?${r}") rs);
   buildCMake = args: stdenv.mkDerivation ({
     nativeBuildInputs = [ cmake ];
-    buildInputs = [ gmp libuv llvmPackages.llvm ];
+    buildInputs = [ gmp llvmPackages.llvm ];
     # https://github.com/NixOS/nixpkgs/issues/60919
     hardeningDisable = [ "all" ];
     dontStrip = (args.debug or debug);
@@ -17,7 +17,7 @@ lib.warn "The Nix-based build is deprecated" rec {
     '';
   } // args // {
     src = args.realSrc or (sourceByRegex args.src [ "[a-z].*" "CMakeLists\.txt" ]);
-    cmakeFlags = (args.cmakeFlags or [ "-DSTAGE=1" "-DPREV_STAGE=./faux-prev-stage" "-DUSE_GITHASH=OFF" "-DCADICAL=${cadical}/bin/cadical" ]) ++ (args.extraCMakeFlags or extraCMakeFlags) ++ lib.optional (args.debug or debug) [ "-DCMAKE_BUILD_TYPE=Debug" ];
+    cmakeFlags = (args.cmakeFlags or [ "-DSTAGE=1" "-DPREV_STAGE=./faux-prev-stage" "-DUSE_GITHASH=OFF" ]) ++ (args.extraCMakeFlags or extraCMakeFlags) ++ lib.optional (args.debug or debug) [ "-DCMAKE_BUILD_TYPE=Debug" ];
     preConfigure = args.preConfigure or "" + ''
       # ignore absence of submodule
       sed -i 's!lake/Lake.lean!!' CMakeLists.txt
@@ -26,7 +26,11 @@ lib.warn "The Nix-based build is deprecated" rec {
   lean-bin-tools-unwrapped = buildCMake {
     name = "lean-bin-tools";
     outputs = [ "out" "leanc_src" ];
-    realSrc = sourceByRegex (src + "/src") [ "CMakeLists\.txt" "[a-z].*" ".*\.in" "Leanc\.lean" ];
+    realSrc = sourceByRegex (src + "/src") [ "CMakeLists\.txt" "cmake.*" "bin.*" "include.*" ".*\.in" "Leanc\.lean" ];
+    preConfigure = ''
+      touch empty.cpp
+      sed -i 's/add_subdirectory.*//;s/set(LEAN_OBJS.*/set(LEAN_OBJS empty.cpp)/' CMakeLists.txt
+    '';
     dontBuild = true;
     installPhase = ''
       mkdir $out $leanc_src
@@ -41,10 +45,11 @@ lib.warn "The Nix-based build is deprecated" rec {
   leancpp = buildCMake {
     name = "leancpp";
     src = src + "/src";
-    buildFlags = [ "leancpp" "leanrt" "leanrt_initial-exec" "leanshell" "leanmain" ];
+    buildFlags = [ "leancpp" "leanrt" "leanrt_initial-exec" "shell" ];
     installPhase = ''
       mkdir -p $out
       mv lib/ $out/
+      mv shell/CMakeFiles/shell.dir/lean.cpp.o $out/lib
       mv runtime/libleanrt_initial-exec.a $out/lib
     '';
   };
@@ -95,13 +100,12 @@ lib.warn "The Nix-based build is deprecated" rec {
       Lean = attachSharedLib leanshared Lean' // { allExternalDeps = [ Std ]; };
       Lake = build {
         name = "Lake";
-        sharedLibName = "Lake_shared";
         src = src + "/src/lake";
         deps = [ Init Lean ];
       };
       Lake-Main = build {
-        name = "LakeMain";
-        roots = [{ glob = "one"; mod = "LakeMain"; }];
+        name = "Lake.Main";
+        roots = [ "Lake.Main" ];
         executableName = "lake";
         deps = [ Lake ];
         linkFlags = lib.optional stdenv.isLinux "-rdynamic";
@@ -118,15 +122,12 @@ lib.warn "The Nix-based build is deprecated" rec {
         touch empty.c
         ${stdenv.cc}/bin/cc -shared -o $out/$libName empty.c
       '';
-      leanshared_1 = runCommand "leanshared_1" { buildInputs = [ stdenv.cc ]; libName = "leanshared_1${stdenv.hostPlatform.extensions.sharedLibrary}"; } ''
-        mkdir $out
-        touch empty.c
-        ${stdenv.cc}/bin/cc -shared -o $out/$libName empty.c
-      '';
       leanshared = runCommand "leanshared" { buildInputs = [ stdenv.cc ]; libName = "libleanshared${stdenv.hostPlatform.extensions.sharedLibrary}"; } ''
         mkdir $out
         LEAN_CC=${stdenv.cc}/bin/cc ${lean-bin-tools-unwrapped}/bin/leanc -shared ${lib.optionalString stdenv.isLinux "-Wl,-Bsymbolic"} \
-          -Wl,--whole-archive ${leancpp}/lib/temp/libleanshell.a -lInit -lStd -lLean -lleancpp ${leancpp}/lib/libleanrt_initial-exec.a -Wl,--no-whole-archive -lstdc++ \
+          ${if stdenv.isDarwin
+            then "-Wl,-force_load,${Init.staticLib}/libInit.a -Wl,-force_load,${Std.staticLib}/libStd.a -Wl,-force_load,${Lean.staticLib}/libLean.a -Wl,-force_load,${leancpp}/lib/lean/libleancpp.a ${leancpp}/lib/libleanrt_initial-exec.a -lc++"
+            else "-Wl,--whole-archive -lInit -lStd -lLean -lleancpp ${leancpp}/lib/libleanrt_initial-exec.a -Wl,--no-whole-archive -lstdc++"} \
           -lm ${stdlibLinkFlags} \
           $(${llvmPackages.libllvm.dev}/bin/llvm-config --ldflags --libs) \
           -o $out/$libName
@@ -134,18 +135,18 @@ lib.warn "The Nix-based build is deprecated" rec {
       mods = foldl' (mods: pkg: mods // pkg.mods) {} stdlib;
       print-paths = Lean.makePrintPathsFor [] mods;
       leanc = writeShellScriptBin "leanc" ''
-        LEAN_CC=${stdenv.cc}/bin/cc ${Leanc.executable}/bin/leanc -I${lean-bin-tools-unwrapped}/include ${stdlibLinkFlags} -L${libInit_shared} -L${leanshared_1} -L${leanshared} -L${Lake.sharedLib} "$@"
+        LEAN_CC=${stdenv.cc}/bin/cc ${Leanc.executable}/bin/leanc -I${lean-bin-tools-unwrapped}/include ${stdlibLinkFlags} -L${libInit_shared} -L${leanshared} "$@"
       '';
       lean = runCommand "lean" { buildInputs = lib.optional stdenv.isDarwin darwin.cctools; } ''
         mkdir -p $out/bin
-        ${leanc}/bin/leanc ${leancpp}/lib/temp/libleanmain.a ${libInit_shared}/* ${leanshared_1}/* ${leanshared}/* -o $out/bin/lean
+        ${leanc}/bin/leanc ${leancpp}/lib/lean.cpp.o ${libInit_shared}/* ${leanshared}/* -o $out/bin/lean
       '';
       # derivation following the directory layout of the "basic" setup, mostly useful for running tests
       lean-all = stdenv.mkDerivation {
         name = "lean-${desc}";
         buildCommand = ''
           mkdir -p $out/bin $out/lib/lean
-          ln -sf ${leancpp}/lib/lean/* ${lib.concatMapStringsSep " " (l: "${l.modRoot}/* ${l.staticLib}/*") (lib.reverseList stdlib)} ${libInit_shared}/* ${leanshared_1}/* ${leanshared}/* ${Lake.sharedLib}/* $out/lib/lean/
+          ln -sf ${leancpp}/lib/lean/* ${lib.concatMapStringsSep " " (l: "${l.modRoot}/* ${l.staticLib}/*") (lib.reverseList stdlib)} ${libInit_shared}/* ${leanshared}/* $out/lib/lean/
           # put everything in a single final derivation so `IO.appDir` references work
           cp ${lean}/bin/lean ${leanc}/bin/leanc ${Lake-Main.executable}/bin/lake $out/bin
           # NOTE: `lndir` will not override existing `bin/leanc`
@@ -159,7 +160,7 @@ lib.warn "The Nix-based build is deprecated" rec {
       test = buildCMake {
         name = "lean-test-${desc}";
         realSrc = lib.sourceByRegex src [ "src.*" "tests.*" ];
-        buildInputs = [ gmp libuv perl git cadical ];
+        buildInputs = [ gmp perl git ];
         preConfigure = ''
           cd src
         '';
@@ -170,7 +171,7 @@ lib.warn "The Nix-based build is deprecated" rec {
           ln -sf ${lean-all}/* .
         '';
         buildPhase = ''
-         ctest --output-junit test-results.xml --output-on-failure -E 'leancomptest_(doc_example|foreign)|leanlaketest_reverse-ffi|leanruntest_timeIO' -j$NIX_BUILD_CORES
+          ctest --output-junit test-results.xml --output-on-failure -E 'leancomptest_(doc_example|foreign)' -j$NIX_BUILD_CORES
         '';
         installPhase = ''
           mkdir $out
@@ -178,7 +179,7 @@ lib.warn "The Nix-based build is deprecated" rec {
         '';
       };
       update-stage0 =
-        let cTree = symlinkJoin { name = "cs"; paths = map (lib: lib.cTree) (stdlib ++ [Lake-Main]); }; in
+        let cTree = symlinkJoin { name = "cs"; paths = map (lib: lib.cTree) stdlib; }; in
         writeShellScriptBin "update-stage0" ''
           CSRCS=${cTree} CP_C_PARAMS="--dereference --no-preserve=all" ${src + "/script/lib/update-stage0"}
         '';

nix/buildLeanPackage.nix

@@ -1,5 +1,5 @@
 { lean, lean-leanDeps ? lean, lean-final ? lean, leanc,
-  stdenv, lib, coreutils, gnused, writeShellScriptBin, bash, substituteAll, symlinkJoin, linkFarmFromDrvs,
+  stdenv, lib, coreutils, gnused, writeShellScriptBin, bash, lean-emacs, lean-vscode, nix, substituteAll, symlinkJoin, linkFarmFromDrvs,
   runCommand, darwin, mkShell, ... }:
 let lean-final' = lean-final; in
 lib.makeOverridable (
@@ -30,7 +30,7 @@ lib.makeOverridable (
   pluginDeps ? [],
   # `overrideAttrs` for `buildMod`
   overrideBuildModAttrs ? null,
-  debug ? false, leanFlags ? [], leancFlags ? [], linkFlags ? [], executableName ? lib.toLower name, libName ? name, sharedLibName ? libName,
+  debug ? false, leanFlags ? [], leancFlags ? [], linkFlags ? [], executableName ? lib.toLower name, libName ? name,
   srcTarget ? "..#stage0", srcArgs ? "(\${args[*]})", lean-final ? lean-final' }@args:
 with builtins; let
   # "Init.Core" ~> "Init/Core"
@@ -197,6 +197,19 @@ with builtins; let
              then map (m: m.module) header.imports
              else abort "errors while parsing imports of ${mod}:\n${lib.concatStringsSep "\n" header.errors}";
     in mkMod mod (map (dep: if modDepsMap ? ${dep} then modCandidates.${dep} else externalModMap.${dep}) deps)) modDepsMap;
+  makeEmacsWrapper = name: emacs: lean: writeShellScriptBin name ''
+    ${emacs} --eval "(progn (setq lean4-rootdir \"${lean}\"))" "$@"
+  '';
+  makeVSCodeWrapper = name: lean: writeShellScriptBin name ''
+    PATH=${lean}/bin:$PATH ${lean-vscode}/bin/code "$@"
+  '';
+  printPaths = deps: writeShellScriptBin "print-paths" ''
+    echo '${toJSON {
+      oleanPath = [(depRoot "print-paths" deps)];
+      srcPath = ["."] ++ map (dep: dep.src) allExternalDeps;
+      loadDynlibPaths = map pathOfSharedLib (loadDynlibsOfDeps deps);
+    }}'
+  '';
   expandGlob = g:
     if typeOf g == "string" then [g]
     else if g.glob == "one" then [g.mod]
@@ -233,7 +246,7 @@ in rec {
   cTree     = symlinkJoin { name = "${name}-cTree"; paths = map (mod: mod.c) (attrValues mods); };
   oTree     = symlinkJoin { name = "${name}-oTree"; paths = (attrValues objects); };
   iTree     = symlinkJoin { name = "${name}-iTree"; paths = map (mod: mod.ilean) (attrValues mods); };
-  sharedLib = mkSharedLib "lib${sharedLibName}" ''
+  sharedLib = mkSharedLib "lib${libName}" ''
     ${if stdenv.isDarwin then "-Wl,-force_load,${staticLib}/lib${libName}.a" else "-Wl,--whole-archive ${staticLib}/lib${libName}.a -Wl,--no-whole-archive"} \
     ${lib.concatStringsSep " " (map (d: "${d.sharedLib}/*") deps)}'';
   executable = lib.makeOverridable ({ withSharedStdlib ? true }: let
@@ -244,4 +257,48 @@ in rec {
         -o $out/bin/${executableName} \
         ${lib.concatStringsSep " " allLinkFlags}
     '') {};
+
+  lean-package = writeShellScriptBin "lean" ''
+    LEAN_PATH=${modRoot}:$LEAN_PATH LEAN_SRC_PATH=$LEAN_SRC_PATH:${src} exec ${lean-final}/bin/lean "$@"
+  '';
+  emacs-package = makeEmacsWrapper "emacs-package" lean-package;
+  vscode-package = makeVSCodeWrapper "vscode-package" lean-package;
+
+  link-ilean = writeShellScriptBin "link-ilean" ''
+    dest=''${1:-.}
+    mkdir -p $dest/build/lib
+    ln -sf ${iTree}/* $dest/build/lib
+  '';
+
+  makePrintPathsFor = deps: mods: printPaths deps // mapAttrs (_: mod: makePrintPathsFor (deps ++ [mod]) mods) mods;
+  print-paths = makePrintPathsFor [] (mods' // externalModMap);
+  # `lean` wrapper that dynamically runs Nix for the actual `lean` executable so the same editor can be
+  # used for multiple projects/after upgrading the `lean` input/for editing both stage 1 and the tests
+  lean-bin-dev = substituteAll {
+    name = "lean";
+    dir = "bin";
+    src = ./lean-dev.in;
+    isExecutable = true;
+    srcRoot = fullSrc;  # use root flake.nix in case of Lean repo
+    inherit bash nix srcTarget srcArgs;
+  };
+  lake-dev = substituteAll {
+    name = "lake";
+    dir = "bin";
+    src = ./lake-dev.in;
+    isExecutable = true;
+    srcRoot = fullSrc;  # use root flake.nix in case of Lean repo
+    inherit bash nix srcTarget srcArgs;
+  };
+  lean-dev = symlinkJoin { name = "lean-dev"; paths = [ lean-bin-dev lake-dev ]; };
+  emacs-dev = makeEmacsWrapper "emacs-dev" "${lean-emacs}/bin/emacs" lean-dev;
+  emacs-path-dev = makeEmacsWrapper "emacs-path-dev" "emacs" lean-dev;
+  vscode-dev = makeVSCodeWrapper "vscode-dev" lean-dev;
+
+  devShell = mkShell {
+    buildInputs = [ nix ];
+    shellHook = ''
+      export LEAN_SRC_PATH="${srcPath}"
+    '';
+  };
 })

nix/packages.nix

@@ -1,6 +1,9 @@
-{ src, pkgs, ... } @ args:
+{ src, pkgs, nix, ... } @ args:
 with pkgs;
 let
+  nix-pinned = writeShellScriptBin "nix" ''
+    ${nix.packages.${system}.default}/bin/nix --experimental-features 'nix-command flakes' --extra-substituters https://lean4.cachix.org/ --option warn-dirty false "$@"
+  '';
   # https://github.com/NixOS/nixpkgs/issues/130963
   llvmPackages = if stdenv.isDarwin then llvmPackages_11 else llvmPackages_15;
   cc = (ccacheWrapper.override rec {
@@ -39,9 +42,40 @@ let
     inherit (lean) stdenv;
     lean = lean.stage1;
     inherit (lean.stage1) leanc;
+    inherit lean-emacs lean-vscode;
+    nix = nix-pinned;
   }));
+  lean4-mode = emacsPackages.melpaBuild {
+    pname = "lean4-mode";
+    version = "1";
+    commit = "1";
+    src = args.lean4-mode;
+    packageRequires = with pkgs.emacsPackages.melpaPackages; [ dash f flycheck magit-section lsp-mode s ];
+    recipe = pkgs.writeText "recipe" ''
+      (lean4-mode
+       :repo "leanprover/lean4-mode"
+       :fetcher github
+       :files ("*.el" "data"))
+    '';
+  };
+  lean-emacs = emacsWithPackages [ lean4-mode ];
+  # updating might be nicer by building from source from a flake input, but this is good enough for now
+  vscode-lean4 = vscode-utils.extensionFromVscodeMarketplace {
+      name = "lean4";
+      publisher = "leanprover";
+      version = "0.0.63";
+      sha256 = "sha256-kjEex7L0F2P4pMdXi4NIZ1y59ywJVubqDqsoYagZNkI=";
+  };
+  lean-vscode = vscode-with-extensions.override {
+    vscodeExtensions = [ vscode-lean4 ];
+  };
 in {
-  inherit cc buildLeanPackage llvmPackages;
+  inherit cc lean4-mode buildLeanPackage llvmPackages vscode-lean4;
+  lean = lean.stage1;
+  stage0print-paths = lean.stage1.Lean.print-paths;
+  HEAD-as-stage0 = (lean.stage1.Lean.overrideArgs { srcTarget = "..#stage0-from-input.stage0"; srcArgs = "(--override-input lean-stage0 ..\?rev=$(git rev-parse HEAD) -- -Dinterpreter.prefer_native=false \"$@\")"; });
+  HEAD-as-stage1 = (lean.stage1.Lean.overrideArgs { srcTarget = "..\?rev=$(git rev-parse HEAD)#stage0"; });
+  nix = nix-pinned;
   nixpkgs = pkgs;
   ciShell = writeShellScriptBin "ciShell" ''
     set -o pipefail
@@ -49,4 +83,5 @@ in {
     # prefix lines with cumulative and individual execution time
     "$@" |& ts -i "(%.S)]" | ts -s "[%M:%S"
   '';
-} // lean.stage1
+  vscode = lean-vscode;
+} // lean.stage1.Lean // lean.stage1 // lean

releases_drafts/varCtorNameLint.md

@@ -0,0 +1,45 @@
+A new linter flags situations where a local variable's name is one of
+the argumentless constructors of its type. This can arise when a user either
+doesn't open a namespace or doesn't add a dot or leading qualifier, as
+in the following:
+
+````
+inductive Tree (α : Type) where
+  | leaf
+  | branch (left : Tree α) (val : α) (right : Tree α)
+
+def depth : Tree α → Nat
+  | leaf => 0
+````
+
+With this linter, the `leaf` pattern is highlighted as a local
+variable whose name overlaps with the constructor `Tree.leaf`.
+
+The linter can be disabled with `set_option linter.constructorNameAsVariable false`.
+
+Additionally, the error message that occurs when a name in a pattern that takes arguments isn't valid now suggests similar names that would be valid. This means that the following definition:
+
+```
+def length (list : List α) : Nat :=
+  match list with
+  | nil => 0
+  | cons x xs => length xs + 1
+```
+
+now results in the following warning:
+
+```
+warning: Local variable 'nil' resembles constructor 'List.nil' - write '.nil' (with a dot) or 'List.nil' to use the constructor.
+note: this linter can be disabled with `set_option linter.constructorNameAsVariable false`
+```
+
+and error:
+
+```
+invalid pattern, constructor or constant marked with '[match_pattern]' expected
+
+Suggestion: 'List.cons' is similar
+```
+
+
+#4301

script/lib/update-stage0

@@ -17,8 +17,8 @@ for f in $(git ls-files src ':!:src/lake/*' ':!:src/Leanc.lean'); do
 done
 
 # special handling for Lake files due to its nested directory
-# copy the README to ensure the `stage0/src/lake` directory is committed
-for f in $(git ls-files 'src/lake/Lake/*' src/lake/Lake.lean src/lake/LakeMain.lean src/lake/README.md ':!:src/lakefile.toml'); do
+# copy the README to ensure the `stage0/src/lake` directory is comitted
+for f in $(git ls-files 'src/lake/Lake/*' src/lake/Lake.lean src/lake/README.md ':!:src/lakefile.toml'); do
     if [[ $f == *.lean ]]; then
         f=${f#src/lake}
         f=${f%.lean}.c

script/prepare-llvm-linux.sh

@@ -38,7 +38,7 @@ $CP $GLIBC/lib/*crt* llvm/lib/
 $CP $GLIBC/lib/*crt* stage1/lib/
 # runtime
 (cd llvm; $CP --parents lib/clang/*/lib/*/{clang_rt.*.o,libclang_rt.builtins*} ../stage1)
-$CP llvm/lib/*/lib{c++,c++abi,unwind}.* $GMP/lib/libgmp.a $LIBUV/lib/libuv.a stage1/lib/
+$CP llvm/lib/*/lib{c++,c++abi,unwind}.* $GMP/lib/libgmp.a stage1/lib/
 # LLVM 15 appears to ship the dependencies in 'llvm/lib/<target-triple>/' and 'llvm/include/<target-triple>/'
 # but clang-15 that we use to compile is linked against 'llvm/lib/' and 'llvm/include'
 # https://github.com/llvm/llvm-project/issues/54955
@@ -48,8 +48,6 @@ $CP llvm-host/lib/*/lib{c++,c++abi,unwind}.* llvm-host/lib/
 $CP -r llvm/include/*-*-* llvm-host/include/
 # glibc: use for linking (so Lean programs don't embed newer symbol versions), but not for running (because libc.so, librt.so, and ld.so must be compatible)!
 $CP $GLIBC/lib/libc_nonshared.a stage1/lib/glibc
-# libpthread_nonshared.a must be linked in order to be able to use `pthread_atfork(3)`. LibUV uses this function.
-$CP $GLIBC/lib/libpthread_nonshared.a stage1/lib/glibc
 for f in $GLIBC/lib/lib{c,dl,m,rt,pthread}-*; do b=$(basename $f); cp $f stage1/lib/glibc/${b%-*}.so; done
 OPTIONS=()
 echo -n " -DLEAN_STANDALONE=ON"
@@ -64,8 +62,8 @@ fi
 # use `-nostdinc` to make sure headers are not visible by default (in particular, not to `#include_next` in the clang headers),
 # but do not change sysroot so users can still link against system libs
 echo -n " -DLEANC_INTERNAL_FLAGS='-nostdinc -isystem ROOT/include/clang' -DLEANC_CC=ROOT/bin/clang"
-echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/glibc ROOT/lib/glibc/libc_nonshared.a ROOT/lib/glibc/libpthread_nonshared.a -Wl,--as-needed -Wl,-Bstatic -lgmp -lunwind -luv -Wl,-Bdynamic -Wl,--no-as-needed -fuse-ld=lld'"
+echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/glibc ROOT/lib/glibc/libc_nonshared.a -Wl,--as-needed -Wl,-Bstatic -lgmp -lunwind -Wl,-Bdynamic -Wl,--no-as-needed -fuse-ld=lld'"
 # when not using the above flags, link GMP dynamically/as usual
-echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-Wl,--as-needed -lgmp -luv -lpthread -ldl -lrt -Wl,--no-as-needed'"
+echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-Wl,--as-needed -lgmp -Wl,--no-as-needed'"
 # do not set `LEAN_CC` for tests
 echo -n " -DLEAN_TEST_VARS=''"

script/prepare-llvm-macos.sh

@@ -9,7 +9,6 @@ set -uxo pipefail
 # use full LLVM release for compiling C++ code, but subset for compiling C code and distribution
 
 GMP=${GMP:-$(brew --prefix)}
-LIBUV=${LIBUV:-$(brew --prefix)}
 
 [[ -d llvm ]] || (mkdir llvm; gtar xf $1 --strip-components 1 --directory llvm)
 [[ -d llvm-host ]] || if [[ "$#" -gt 1 ]]; then
@@ -47,9 +46,8 @@ echo -n " -DLEAN_EXTRA_CXX_FLAGS='${EXTRA_FLAGS:-}'"
 if [[ -L llvm-host ]]; then
   echo -n " -DCMAKE_C_COMPILER=$PWD/stage1/bin/clang"
   gcp $GMP/lib/libgmp.a stage1/lib/
-  gcp $LIBUV/lib/libuv.a stage1/lib/
   echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/libc -fuse-ld=lld'"
-  echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-lgmp -luv'"
+  echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-lgmp'"
 else
   echo -n " -DCMAKE_C_COMPILER=$PWD/llvm-host/bin/clang -DLEANC_OPTS='--sysroot $PWD/stage1 -resource-dir $PWD/stage1/lib/clang/15.0.1 ${EXTRA_FLAGS:-}'"
   echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/libc -fuse-ld=lld'"

script/prepare-llvm-mingw.sh

@@ -31,21 +31,15 @@ cp /clang64/lib/{crtbegin,crtend,crt2,dllcrt2}.o stage1/lib/
 # runtime
 (cd llvm; cp --parents lib/clang/*/lib/*/libclang_rt.builtins* ../stage1)
 # further dependencies
-# Note: even though we're linking against libraries like `libbcrypt.a` which appear to be static libraries from the file name,
-# we're not actually linking statically against the code.
-# Rather, `libbcrypt.a` is an import library (see https://en.wikipedia.org/wiki/Dynamic-link_library#Import_libraries) that just
-# tells the compiler how to dynamically link against `bcrypt.dll` (which is located in the System32 folder).
-# This distinction is relevant specifically for `libicu.a`/`icu.dll` because there we want updates to the time zone database to
-# be delivered to users via Windows Update without having to recompile Lean or Lean programs.
-cp /clang64/lib/lib{m,bcrypt,mingw32,moldname,mingwex,msvcrt,pthread,advapi32,shell32,user32,kernel32,ucrtbase,psapi,iphlpapi,userenv,ws2_32,dbghelp,ole32,icu}.* /clang64/lib/libgmp.a /clang64/lib/libuv.a llvm/lib/lib{c++,c++abi,unwind}.a stage1/lib/
+cp /clang64/lib/lib{m,bcrypt,mingw32,moldname,mingwex,msvcrt,pthread,advapi32,shell32,user32,kernel32,ucrtbase}.* /clang64/lib/libgmp.a llvm/lib/lib{c++,c++abi,unwind}.a stage1/lib/
 echo -n " -DLEAN_STANDALONE=ON"
 echo -n " -DCMAKE_C_COMPILER=$PWD/stage1/bin/clang.exe -DCMAKE_C_COMPILER_WORKS=1 -DCMAKE_CXX_COMPILER=$PWD/llvm/bin/clang++.exe -DCMAKE_CXX_COMPILER_WORKS=1 -DLEAN_CXX_STDLIB='-lc++ -lc++abi'"
 echo -n " -DSTAGE0_CMAKE_C_COMPILER=clang -DSTAGE0_CMAKE_CXX_COMPILER=clang++"
 echo -n " -DLEAN_EXTRA_CXX_FLAGS='--sysroot $PWD/llvm -idirafter /clang64/include/'"
 echo -n " -DLEANC_INTERNAL_FLAGS='--sysroot ROOT -nostdinc -isystem ROOT/include/clang' -DLEANC_CC=ROOT/bin/clang.exe"
-echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -static-libgcc -Wl,-Bstatic -lgmp $(pkg-config --static --libs libuv) -lunwind -Wl,-Bdynamic -fuse-ld=lld'"
-# when not using the above flags, link GMP dynamically/as usual. Always link ICU dynamically.
-echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-lgmp $(pkg-config --libs libuv) -lucrtbase'"
+echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -static-libgcc -Wl,-Bstatic -lgmp -lunwind -Wl,-Bdynamic -fuse-ld=lld'"
+# when not using the above flags, link GMP dynamically/as usual
+echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-lgmp -lucrtbase'"
 # do not set `LEAN_CC` for tests
 echo -n " -DAUTO_THREAD_FINALIZATION=OFF -DSTAGE0_AUTO_THREAD_FINALIZATION=OFF"
 echo -n " -DLEAN_TEST_VARS=''"

src/CMakeLists.txt

@@ -1,6 +1,5 @@
 cmake_minimum_required(VERSION 3.10)
 cmake_policy(SET CMP0054 NEW)
-cmake_policy(SET CMP0110 NEW)
 if(NOT (${CMAKE_GENERATOR} MATCHES "Unix Makefiles"))
   message(FATAL_ERROR "The only supported CMake generator at the moment is 'Unix Makefiles'")
 endif()
@@ -10,15 +9,13 @@ endif()
 include(ExternalProject)
 project(LEAN CXX C)
 set(LEAN_VERSION_MAJOR 4)
-set(LEAN_VERSION_MINOR 15)
+set(LEAN_VERSION_MINOR 11)
 set(LEAN_VERSION_PATCH 0)
 set(LEAN_VERSION_IS_RELEASE 0)  # This number is 1 in the release revision, and 0 otherwise.
 set(LEAN_SPECIAL_VERSION_DESC "" CACHE STRING "Additional version description like 'nightly-2018-03-11'")
 set(LEAN_VERSION_STRING "${LEAN_VERSION_MAJOR}.${LEAN_VERSION_MINOR}.${LEAN_VERSION_PATCH}")
 if (LEAN_SPECIAL_VERSION_DESC)
   string(APPEND LEAN_VERSION_STRING "-${LEAN_SPECIAL_VERSION_DESC}")
-elseif (NOT LEAN_VERSION_IS_RELEASE)
-  string(APPEND LEAN_VERSION_STRING "-pre")
 endif()
 
 set(LEAN_PLATFORM_TARGET "" CACHE STRING "LLVM triple of the target platform")
@@ -157,10 +154,6 @@ endif ()
 # We want explicit stack probes in huge Lean stack frames for robust stack overflow detection
 string(APPEND LEANC_EXTRA_FLAGS " -fstack-clash-protection")
 
-# This makes signed integer overflow guaranteed to match 2's complement.
-string(APPEND CMAKE_CXX_FLAGS " -fwrapv")
-string(APPEND LEANC_EXTRA_FLAGS " -fwrapv")
-
 if(NOT MULTI_THREAD)
   message(STATUS "Disabled multi-thread support, it will not be safe to run multiple threads in parallel")
   set(AUTO_THREAD_FINALIZATION OFF)
@@ -249,77 +242,6 @@ if("${USE_GMP}" MATCHES "ON")
   endif()
 endif()
 
-# LibUV
-if("${CMAKE_SYSTEM_NAME}" MATCHES "Emscripten")
-  # Only on WebAssembly we compile LibUV ourselves
-  set(LIBUV_EMSCRIPTEN_FLAGS "${EMSCRIPTEN_SETTINGS}")
-
-  # LibUV does not compile on WebAssembly without modifications because
-  # building LibUV on a platform requires including stub implementations
-  # for features not present on the target platform. This patch includes
-  # the minimum amount of stub implementations needed for successfully
-  # running Lean on WebAssembly and using LibUV's temporary file support.
-  # It still leaves several symbols completely undefined: uv__fs_event_close,
-  # uv__hrtime, uv__io_check_fd, uv__io_fork, uv__io_poll, uv__platform_invalidate_fd
-  # uv__platform_loop_delete, uv__platform_loop_init. Making additional
-  # LibUV features available on WebAssembly might require adapting the
-  # patch to include additional LibUV source files.
-  set(LIBUV_PATCH_IN "
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index 5e8e0166..f3b29134 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -317,6 +317,11 @@ if(CMAKE_SYSTEM_NAME STREQUAL \"GNU\")
-        src/unix/hurd.c)
- endif()
-
-+if(CMAKE_SYSTEM_NAME STREQUAL \"Emscripten\")
-+  list(APPEND uv_sources
-+       src/unix/no-proctitle.c)
-+endif()
-+
- if(CMAKE_SYSTEM_NAME STREQUAL \"Linux\")
-   list(APPEND uv_defines _GNU_SOURCE _POSIX_C_SOURCE=200112)
-   list(APPEND uv_libraries dl rt)
-")
-  string(REPLACE "\n" "\\n" LIBUV_PATCH ${LIBUV_PATCH_IN})
-
-  ExternalProject_add(libuv
-    PREFIX libuv
-    GIT_REPOSITORY https://github.com/libuv/libuv
-    # Sync version with flake.nix
-    GIT_TAG v1.48.0
-    CMAKE_ARGS -DCMAKE_BUILD_TYPE=Release -DLIBUV_BUILD_TESTS=OFF -DLIBUV_BUILD_SHARED=OFF -DCMAKE_AR=${CMAKE_AR} -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE} -DCMAKE_POSITION_INDEPENDENT_CODE=ON -DCMAKE_C_FLAGS=${LIBUV_EMSCRIPTEN_FLAGS}
-	  PATCH_COMMAND git reset --hard HEAD && printf "${LIBUV_PATCH}" > patch.diff && git apply patch.diff
-    BUILD_IN_SOURCE ON
-    INSTALL_COMMAND "")
-  set(LIBUV_INCLUDE_DIR "${CMAKE_BINARY_DIR}/libuv/src/libuv/include")
-  set(LIBUV_LIBRARIES "${CMAKE_BINARY_DIR}/libuv/src/libuv/libuv.a")
-else()
-  find_package(LibUV 1.0.0 REQUIRED)
-endif()
-include_directories(${LIBUV_INCLUDE_DIR})
-if(NOT LEAN_STANDALONE)
-  string(APPEND LEAN_EXTRA_LINKER_FLAGS " ${LIBUV_LIBRARIES}")
-endif()
-
-# Windows SDK (for ICU)
-if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  # Pass 'tools' to skip MSVC version check (as MSVC/Visual Studio is not necessarily installed)
-  find_package(WindowsSDK REQUIRED COMPONENTS tools)
-
-  # This will give a semicolon-separated list of include directories
-  get_windowssdk_include_dirs(${WINDOWSSDK_LATEST_DIR} WINDOWSSDK_INCLUDE_DIRS)
-
-  # To successfully build against Windows SDK headers, the Windows SDK headers must have lower
-  # priority than other system headers, so use `-idirafter`. Unfortunately, CMake does not
-  # support this using `include_directories`.
-  string(REPLACE ";" "\" -idirafter \"" WINDOWSSDK_INCLUDE_DIRS "${WINDOWSSDK_INCLUDE_DIRS}")
-  string(APPEND CMAKE_CXX_FLAGS " -idirafter \"${WINDOWSSDK_INCLUDE_DIRS}\"")
-
-  string(APPEND LEAN_EXTRA_LINKER_FLAGS " -licu")
-endif()
-
 # ccache
 if(CCACHE AND NOT CMAKE_CXX_COMPILER_LAUNCHER AND NOT CMAKE_C_COMPILER_LAUNCHER)
   find_program(CCACHE_PATH ccache)
@@ -401,12 +323,7 @@ if(NOT LEAN_STANDALONE)
 endif()
 
 # flags for user binaries = flags for toolchain binaries + Lake
-set(LEANC_STATIC_LINKER_FLAGS " ${TOOLCHAIN_STATIC_LINKER_FLAGS} -lLake")
-if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
-  set(LEANC_SHARED_LINKER_FLAGS " ${TOOLCHAIN_SHARED_LINKER_FLAGS} -Wl,--as-needed -lLake_shared -Wl,--no-as-needed")
-else()
-  set(LEANC_SHARED_LINKER_FLAGS " ${TOOLCHAIN_SHARED_LINKER_FLAGS} -lLake_shared")
-endif()
+string(APPEND LEANC_STATIC_LINKER_FLAGS " ${TOOLCHAIN_STATIC_LINKER_FLAGS} -lLake")
 
 if (LLVM)
   string(APPEND LEANSHARED_LINKER_FLAGS " -L${LLVM_CONFIG_LIBDIR} ${LLVM_CONFIG_LDFLAGS} ${LLVM_CONFIG_LIBS} ${LLVM_CONFIG_SYSTEM_LIBS}")
@@ -451,20 +368,15 @@ if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   string(APPEND CMAKE_CXX_FLAGS " -fPIC -ftls-model=initial-exec")
   string(APPEND LEANC_EXTRA_FLAGS " -fPIC")
   string(APPEND TOOLCHAIN_SHARED_LINKER_FLAGS " -Wl,-rpath=\\$$ORIGIN/..:\\$$ORIGIN")
-  string(APPEND LAKESHARED_LINKER_FLAGS " -Wl,--whole-archive ${CMAKE_BINARY_DIR}/lib/temp/libLake.a.export -Wl,--no-whole-archive")
   string(APPEND CMAKE_EXE_LINKER_FLAGS " -Wl,-rpath=\\\$ORIGIN/../lib:\\\$ORIGIN/../lib/lean")
 elseif(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   string(APPEND CMAKE_CXX_FLAGS " -ftls-model=initial-exec")
   string(APPEND INIT_SHARED_LINKER_FLAGS " -install_name @rpath/libInit_shared.dylib")
-  string(APPEND LEANSHARED_1_LINKER_FLAGS " -install_name @rpath/libleanshared_1.dylib")
   string(APPEND LEANSHARED_LINKER_FLAGS " -install_name @rpath/libleanshared.dylib")
-  string(APPEND LAKESHARED_LINKER_FLAGS " -Wl,-force_load,${CMAKE_BINARY_DIR}/lib/temp/libLake.a.export -install_name @rpath/libLake_shared.dylib")
   string(APPEND CMAKE_EXE_LINKER_FLAGS " -Wl,-rpath,@executable_path/../lib -Wl,-rpath,@executable_path/../lib/lean")
 elseif(${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
   string(APPEND CMAKE_CXX_FLAGS " -fPIC")
   string(APPEND LEANC_EXTRA_FLAGS " -fPIC")
-elseif(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  string(APPEND LAKESHARED_LINKER_FLAGS " -Wl,--out-implib,${CMAKE_BINARY_DIR}/lib/lean/libLake_shared.dll.a -Wl,--whole-archive ${CMAKE_BINARY_DIR}/lib/temp/libLake.a.export -Wl,--no-whole-archive")
 endif()
 
 if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
@@ -489,8 +401,8 @@ endif()
 # executable or `leanshared`, plugins would try to look them up at load time (even though they
 # are already loaded) and probably fail unless we set up LD_LIBRARY_PATH.
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  # import libraries created by the stdlib.make targets
-  string(APPEND LEANC_SHARED_LINKER_FLAGS " -lInit_shared -lleanshared_1 -lleanshared")
+  # import library created by the `leanshared` target
+  string(APPEND LEANC_SHARED_LINKER_FLAGS " -lInit_shared -lleanshared")
 elseif("${CMAKE_SYSTEM_NAME}" MATCHES "Darwin")
   string(APPEND LEANC_SHARED_LINKER_FLAGS " -Wl,-undefined,dynamic_lookup")
 endif()
@@ -503,7 +415,7 @@ endif()
 # Git HASH
 if(USE_GITHASH)
   include(GetGitRevisionDescription)
-  get_git_head_revision(GIT_REFSPEC GIT_SHA1 ALLOW_LOOKING_ABOVE_CMAKE_SOURCE_DIR)
+  get_git_head_revision(GIT_REFSPEC GIT_SHA1)
   if(${GIT_SHA1} MATCHES "GITDIR-NOTFOUND")
     message(STATUS "Failed to read git_sha1")
     set(GIT_SHA1 "")
@@ -547,22 +459,6 @@ if(CMAKE_OSX_SYSROOT AND NOT LEAN_STANDALONE)
   string(APPEND LEANC_EXTRA_FLAGS " ${CMAKE_CXX_SYSROOT_FLAG}${CMAKE_OSX_SYSROOT}")
 endif()
 
-add_subdirectory(initialize)
-add_subdirectory(shell)
-# to be included in `leanshared` but not the smaller `leanshared_1` (as it would pull
-# in the world)
-add_library(leaninitialize STATIC $<TARGET_OBJECTS:initialize>)
-set_target_properties(leaninitialize PROPERTIES
-  ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib/temp
-  OUTPUT_NAME leaninitialize)
-add_library(leanshell STATIC util/shell.cpp)
-set_target_properties(leanshell PROPERTIES
-  ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib/temp
-  OUTPUT_NAME leanshell)
-if (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  string(APPEND CMAKE_EXE_LINKER_FLAGS " -Wl,--whole-archive -lleanmanifest -Wl,--no-whole-archive")
-endif()
-
 if(${STAGE} GREATER 1)
   # reuse C++ parts, which don't change
   add_library(leanrt_initial-exec STATIC IMPORTED)
@@ -571,17 +467,13 @@ if(${STAGE} GREATER 1)
   add_library(leanrt STATIC IMPORTED)
   set_target_properties(leanrt PROPERTIES
     IMPORTED_LOCATION "${CMAKE_BINARY_DIR}/lib/lean/libleanrt.a")
-  add_library(leancpp_1 STATIC IMPORTED)
-  set_target_properties(leancpp_1 PROPERTIES
-    IMPORTED_LOCATION "${CMAKE_BINARY_DIR}/lib/temp/libleancpp_1.a")
   add_library(leancpp STATIC IMPORTED)
   set_target_properties(leancpp PROPERTIES
     IMPORTED_LOCATION "${CMAKE_BINARY_DIR}/lib/lean/libleancpp.a")
   add_custom_target(copy-leancpp
     COMMAND cmake -E copy_if_different "${PREV_STAGE}/runtime/libleanrt_initial-exec.a" "${CMAKE_BINARY_DIR}/runtime/libleanrt_initial-exec.a"
     COMMAND cmake -E copy_if_different "${PREV_STAGE}/lib/lean/libleanrt.a" "${CMAKE_BINARY_DIR}/lib/lean/libleanrt.a"
-    COMMAND cmake -E copy_if_different "${PREV_STAGE}/lib/lean/libleancpp.a" "${CMAKE_BINARY_DIR}/lib/lean/libleancpp.a"
-    COMMAND cmake -E copy_if_different "${PREV_STAGE}/lib/temp/libleancpp_1.a" "${CMAKE_BINARY_DIR}/lib/temp/libleancpp_1.a")
+    COMMAND cmake -E copy_if_different "${PREV_STAGE}/lib/lean/libleancpp.a" "${CMAKE_BINARY_DIR}/lib/lean/libleancpp.a")
   add_dependencies(leancpp copy-leancpp)
   if(LLVM)
       add_custom_target(copy-lean-h-bc
@@ -590,10 +482,6 @@ if(${STAGE} GREATER 1)
   endif()
 else()
   add_subdirectory(runtime)
-  if("${CMAKE_SYSTEM_NAME}" MATCHES "Emscripten")
-    add_dependencies(leanrt libuv)
-    add_dependencies(leanrt_initial-exec libuv)
-  endif()
 
   add_subdirectory(util)
   set(LEAN_OBJS ${LEAN_OBJS} $<TARGET_OBJECTS:util>)
@@ -605,23 +493,14 @@ else()
   set(LEAN_OBJS ${LEAN_OBJS} $<TARGET_OBJECTS:constructions>)
   add_subdirectory(library/compiler)
   set(LEAN_OBJS ${LEAN_OBJS} $<TARGET_OBJECTS:compiler>)
+  add_subdirectory(initialize)
+  set(LEAN_OBJS ${LEAN_OBJS} $<TARGET_OBJECTS:initialize>)
 
-  # leancpp without `initialize` (see `leaninitialize` above)
-  add_library(leancpp_1 STATIC ${LEAN_OBJS})
-  set_target_properties(leancpp_1 PROPERTIES
-    ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib/temp
-    OUTPUT_NAME leancpp_1)
-  add_library(leancpp STATIC ${LEAN_OBJS} $<TARGET_OBJECTS:initialize>)
+  add_library(leancpp STATIC ${LEAN_OBJS})
   set_target_properties(leancpp PROPERTIES
     OUTPUT_NAME leancpp)
 endif()
 
-if((${STAGE} GREATER 0) AND CADICAL)
-  add_custom_target(copy-cadical
-    COMMAND cmake -E copy_if_different "${CADICAL}" "${CMAKE_BINARY_DIR}/bin/cadical${CMAKE_EXECUTABLE_SUFFIX}")
-  add_dependencies(leancpp copy-cadical)
-endif()
-
 # MSYS2 bash usually handles Windows paths relatively well, but not when putting them in the PATH
 string(REGEX REPLACE "^([a-zA-Z]):" "/\\1" LEAN_BIN "${CMAKE_BINARY_DIR}/bin")
 
@@ -629,15 +508,25 @@ string(REGEX REPLACE "^([a-zA-Z]):" "/\\1" LEAN_BIN "${CMAKE_BINARY_DIR}/bin")
 # (also looks nicer in the build log)
 file(RELATIVE_PATH LIB ${LEAN_SOURCE_DIR} ${CMAKE_BINARY_DIR}/lib)
 
+# set up libInit_shared only on Windows; see also stdlib.make.in
+if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+  set(INIT_SHARED_LINKER_FLAGS "-Wl,--whole-archive ${CMAKE_BINARY_DIR}/lib/temp/libInit.a.export ${CMAKE_BINARY_DIR}/lib/temp/libStd.a.export ${CMAKE_BINARY_DIR}/runtime/libleanrt_initial-exec.a -Wl,--no-whole-archive -Wl,--out-implib,${CMAKE_BINARY_DIR}/lib/lean/libInit_shared.dll.a")
+endif()
+
+if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+  set(LEANSHARED_LINKER_FLAGS "-Wl,-force_load,${CMAKE_BINARY_DIR}/lib/lean/libInit.a -Wl,-force_load,${CMAKE_BINARY_DIR}/lib/lean/libStd.a -Wl,-force_load,${CMAKE_BINARY_DIR}/lib/lean/libLean.a -Wl,-force_load,${CMAKE_BINARY_DIR}/lib/lean/libleancpp.a ${CMAKE_BINARY_DIR}/runtime/libleanrt_initial-exec.a ${LEANSHARED_LINKER_FLAGS}")
+elseif(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
+  set(LEANSHARED_LINKER_FLAGS "-Wl,--whole-archive ${CMAKE_BINARY_DIR}/lib/temp/libLean.a.export -lleancpp -Wl,--no-whole-archive -lInit_shared -Wl,--out-implib,${CMAKE_BINARY_DIR}/lib/lean/libleanshared.dll.a")
+else()
+  set(LEANSHARED_LINKER_FLAGS "-Wl,--whole-archive -lInit -lStd -lLean -lleancpp -Wl,--no-whole-archive ${CMAKE_BINARY_DIR}/runtime/libleanrt_initial-exec.a ${LEANSHARED_LINKER_FLAGS}")
+endif()
+
 if (${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
   # We do not use dynamic linking via leanshared for Emscripten to keep things
   # simple. (And we are not interested in `Lake` anyway.) To use dynamic
   # linking, we would probably have to set MAIN_MODULE=2 on `leanshared`,
   # SIDE_MODULE=2 on `lean`, and set CMAKE_SHARED_LIBRARY_SUFFIX to ".js".
-  # We set `ERROR_ON_UNDEFINED_SYMBOLS=0` because our build of LibUV does not
-  # define all symbols, see the comment about LibUV on WebAssembly further up
-  # in this file.
-  string(APPEND LEAN_EXE_LINKER_FLAGS " ${LIB}/temp/libleanshell.a ${TOOLCHAIN_STATIC_LINKER_FLAGS} ${EMSCRIPTEN_SETTINGS} -lnodefs.js -s EXIT_RUNTIME=1 -s MAIN_MODULE=1 -s LINKABLE=1 -s EXPORT_ALL=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0")
+  string(APPEND LEAN_EXE_LINKER_FLAGS " ${TOOLCHAIN_STATIC_LINKER_FLAGS} ${EMSCRIPTEN_SETTINGS} -lnodefs.js -s EXIT_RUNTIME=1 -s MAIN_MODULE=1 -s LINKABLE=1 -s EXPORT_ALL=1")
 endif()
 
 # Build the compiler using the bootstrapped C sources for stage0, and use
@@ -671,13 +560,8 @@ if(${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
   )
   add_custom_target(leanshared ALL
     DEPENDS Init_shared leancpp
-    COMMAND touch ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libleanshared_1${CMAKE_SHARED_LIBRARY_SUFFIX}
     COMMAND touch ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libleanshared${CMAKE_SHARED_LIBRARY_SUFFIX}
   )
-  add_custom_target(lake_shared ALL
-    DEPENDS leanshared
-    COMMAND touch ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/libLake_shared${CMAKE_SHARED_LIBRARY_SUFFIX}
-  )
 else()
   add_custom_target(Init_shared ALL
     WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
@@ -687,29 +571,19 @@ else()
 
   add_custom_target(leanshared ALL
     WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
-    DEPENDS Init_shared leancpp_1 leancpp leanshell leaninitialize
+    DEPENDS Init_shared leancpp
     COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make leanshared
     VERBATIM)
 
-  string(APPEND CMAKE_EXE_LINKER_FLAGS " -lInit_shared -lleanshared_1 -lleanshared")
+  string(APPEND CMAKE_EXE_LINKER_FLAGS " -lInit_shared -lleanshared")
 endif()
 
 if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Emscripten")
-  add_custom_target(lake_lib ALL
+  add_custom_target(lake ALL
     WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
     DEPENDS leanshared
     COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make Lake
     VERBATIM)
-  add_custom_target(lake_shared ALL
-    WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
-    DEPENDS lake_lib
-    COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make libLake_shared
-    VERBATIM)
-  add_custom_target(lake ALL
-    WORKING_DIRECTORY ${LEAN_SOURCE_DIR}
-    DEPENDS lake_shared
-    COMMAND $(MAKE) -f ${CMAKE_BINARY_DIR}/stdlib.make lake
-    VERBATIM)
 endif()
 
 if(PREV_STAGE)
@@ -738,9 +612,7 @@ file(COPY ${LEAN_SOURCE_DIR}/bin/leanmake DESTINATION ${CMAKE_BINARY_DIR}/bin)
 
 install(DIRECTORY "${CMAKE_BINARY_DIR}/bin/" USE_SOURCE_PERMISSIONS DESTINATION bin)
 
-if (${STAGE} GREATER 0 AND CADICAL)
-  install(PROGRAMS "${CADICAL}" DESTINATION bin)
-endif()
+add_subdirectory(shell)
 
 add_custom_target(clean-stdlib
   COMMAND rm -rf "${CMAKE_BINARY_DIR}/lib" || true)

src/Init.lean

@@ -35,5 +35,3 @@ import Init.Ext
 import Init.Omega
 import Init.MacroTrace
 import Init.Grind
-import Init.While
-import Init.Syntax

src/Init/ByCases.lean

@@ -37,26 +37,42 @@ theorem apply_ite (f : α → β) (P : Prop) [Decidable P] (x y : α) :
     f (ite P x y) = ite P (f x) (f y) :=
   apply_dite f P (fun _ => x) (fun _ => y)
 
+@[simp] theorem dite_eq_left_iff {P : Prop} [Decidable P] {B : ¬ P → α} :
+    dite P (fun _ => a) B = a ↔ ∀ h, B h = a := by
+  by_cases P <;> simp [*, forall_prop_of_true, forall_prop_of_false]
+
+@[simp] theorem dite_eq_right_iff {P : Prop} [Decidable P] {A : P → α} :
+    (dite P A fun _ => b) = b ↔ ∀ h, A h = b := by
+  by_cases P <;> simp [*, forall_prop_of_true, forall_prop_of_false]
+
+@[simp] theorem ite_eq_left_iff {P : Prop} [Decidable P] : ite P a b = a ↔ ¬P → b = a :=
+  dite_eq_left_iff
+
+@[simp] theorem ite_eq_right_iff {P : Prop} [Decidable P] : ite P a b = b ↔ P → a = b :=
+  dite_eq_right_iff
+
 /-- 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
 
-@[deprecated "Use `ite_eq_right_iff`" (since := "2024-09-18")]
+-- We don't mark this as `simp` as it is already handled by `ite_eq_right_iff`.
 theorem ite_some_none_eq_none [Decidable P] :
     (if P then some x else none) = none ↔ ¬ P := by
-  simp only [ite_eq_right_iff, reduceCtorEq]
+  simp only [ite_eq_right_iff]
   rfl
 
-@[deprecated "Use `Option.ite_none_right_eq_some`" (since := "2024-09-18")]
-theorem ite_some_none_eq_some [Decidable P] :
+@[simp] theorem ite_some_none_eq_some [Decidable P] :
     (if P then some x else none) = some y ↔ P ∧ x = y := by
   split <;> simp_all
 
-@[deprecated "Use `dite_eq_right_iff" (since := "2024-09-18")]
+-- This is not marked as `simp` as it is already handled by `dite_eq_right_iff`.
 theorem dite_some_none_eq_none [Decidable P] {x : P → α} :
     (if h : P then some (x h) else none) = none ↔ ¬P := by
-  simp
+  simp only [dite_eq_right_iff]
+  rfl
 
-@[deprecated "Use `Option.dite_none_right_eq_some`" (since := "2024-09-18")]
-theorem dite_some_none_eq_some [Decidable P] {x : P → α} {y : α} :
+@[simp] theorem dite_some_none_eq_some [Decidable P] {x : P → α} {y : α} :
     (if h : P then some (x h) else none) = some y ↔ ∃ h : P, x h = y := by
-  by_cases h : P <;> simp [h]
+  by_cases h : P <;> simp only [h, dite_cond_eq_true, dite_cond_eq_false, Option.some.injEq,
+    false_iff, not_exists]
+  case pos => exact ⟨fun h_eq ↦ Exists.intro h h_eq, fun h_exists => h_exists.2⟩
+  case neg => exact fun h_false _ ↦ h_false

src/Init/Classical.lean

@@ -80,8 +80,6 @@ noncomputable scoped instance (priority := low) propDecidable (a : Prop) : Decid
 noncomputable def decidableInhabited (a : Prop) : Inhabited (Decidable a) where
   default := inferInstance
 
-instance (a : Prop) : Nonempty (Decidable a) := ⟨propDecidable a⟩
-
 noncomputable def typeDecidableEq (α : Sort u) : DecidableEq α :=
   fun _ _ => inferInstance
 
@@ -123,11 +121,11 @@ theorem propComplete (a : Prop) : a = True ∨ a = False :=
   | Or.inl ha => Or.inl (eq_true ha)
   | Or.inr hn => Or.inr (eq_false hn)
 
--- this supersedes byCases in Decidable
+-- this supercedes byCases in Decidable
 theorem byCases {p q : Prop} (hpq : p → q) (hnpq : ¬p → q) : q :=
   Decidable.byCases (dec := propDecidable _) hpq hnpq
 
--- this supersedes byContradiction in Decidable
+-- this supercedes byContradiction in Decidable
 theorem byContradiction {p : Prop} (h : ¬p → False) : p :=
   Decidable.byContradiction (dec := propDecidable _) h
 
@@ -136,30 +134,6 @@ The left-to-right direction, double negation elimination (DNE),
 is classically true but not constructively. -/
 @[simp] theorem not_not : ¬¬a ↔ a := Decidable.not_not
 
-/-- Transfer decidability of `¬ p` to decidability of `p`. -/
--- This can not be an instance as it would be tried everywhere.
-def decidable_of_decidable_not (p : Prop) [h : Decidable (¬ p)] : Decidable p :=
-  match h with
-  | isFalse h => isTrue (Classical.not_not.mp h)
-  | isTrue h => isFalse h
-
-attribute [local instance] decidable_of_decidable_not in
-/-- Negation of the condition `P : Prop` in a `dite` is the same as swapping the branches. -/
-@[simp low] protected theorem dite_not [hn : Decidable (¬p)] (x : ¬p → α) (y : ¬¬p → α) :
-    dite (¬p) x y = dite p (fun h => y (not_not_intro h)) x := by
-  cases hn <;> rename_i g
-  · simp [not_not.mp g]
-  · simp [g]
-
-attribute [local instance] decidable_of_decidable_not in
-/-- Negation of the condition `P : Prop` in a `ite` is the same as swapping the branches. -/
-@[simp low] protected theorem ite_not (p : Prop) [Decidable (¬ p)] (x y : α) : ite (¬p) x y = ite p y x :=
-  dite_not (fun _ => x) (fun _ => y)
-
-attribute [local instance] decidable_of_decidable_not in
-@[simp low] protected theorem decide_not (p : Prop) [Decidable (¬ p)] : decide (¬p) = !decide p :=
-  byCases (fun h : p => by simp_all) (fun h => by simp_all)
-
 @[simp low] theorem not_forall {p : α → Prop} : (¬∀ x, p x) ↔ ∃ x, ¬p x := Decidable.not_forall
 
 theorem not_forall_not {p : α → Prop} : (¬∀ x, ¬p x) ↔ ∃ x, p x := Decidable.not_forall_not
@@ -186,7 +160,7 @@ theorem not_iff : ¬(a ↔ b) ↔ (¬a ↔ b) := Decidable.not_iff
 
 @[simp] theorem not_imp : ¬(a → b) ↔ a ∧ ¬b := Decidable.not_imp_iff_and_not
 
-@[simp] theorem imp_and_neg_imp_iff (p : Prop) {q : Prop} : (p → q) ∧ (¬p → q) ↔ q :=
+@[simp] theorem imp_and_neg_imp_iff (p q : Prop) : (p → q) ∧ (¬p → q) ↔ q :=
   Iff.intro (fun (a : _ ∧ _) => (Classical.em p).rec a.left a.right)
             (fun a => And.intro (fun _ => a) (fun _ => a))
 

src/Init/Control/Basic.lean

@@ -8,42 +8,6 @@ import Init.Core
 
 universe u v w
 
-/--
-A `ForIn'` instance, which handles `for h : x in c do`,
-can also handle `for x in x do` by ignoring `h`, and so provides a `ForIn` instance.
-
-Note that this instance will cause a potentially non-defeq duplication if both `ForIn` and `ForIn'`
-instances are provided for the same type.
--/
--- We set the priority to 500 so it is below the default,
--- but still above the low priority instance from `Stream`.
-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} [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
-  simp [instForInOfForIn']
-  congr
-  apply funext
-  intro a
-  apply funext
-  intro m
-  apply funext
-  intro b
-  simp [h]
-  rfl
-
-/-- Extract the value from a `ForInStep`, ignoring whether it is `done` or `yield`. -/
-def ForInStep.value (x : ForInStep α) : α :=
-  match x with
-  | ForInStep.done b => b
-  | ForInStep.yield b => b
-
-@[simp] theorem ForInStep.value_done (b : β) : (ForInStep.done b).value = b := rfl
-@[simp] theorem ForInStep.value_yield (b : β) : (ForInStep.yield b).value = b := rfl
-
 @[reducible]
 def Functor.mapRev {f : Type u → Type v} [Functor f] {α β : Type u} : f α → (α → β) → f β :=
   fun a f => f <$> a
@@ -64,7 +28,7 @@ Important instances include
 * `Option`, where `failure := none` and `<|>` returns the left-most `some`.
 * Parser combinators typically provide an `Applicative` instance for error-handling and
   backtracking.
-
+  
 Error recovery and state can interact subtly. For example, the implementation of `Alternative` for `OptionT (StateT σ Id)` keeps modifications made to the state while recovering from failure, while `StateT σ (OptionT Id)` discards them.
 -/
 -- NB: List instance is in mathlib. Once upstreamed, add

src/Init/Control/ExceptCps.lean

@@ -34,7 +34,7 @@ instance : Monad (ExceptCpsT ε m) where
   bind x f := fun _ k₁ k₂ => x _ (fun a => f a _ k₁ k₂) k₂
 
 instance : LawfulMonad (ExceptCpsT σ m) := by
-  refine LawfulMonad.mk' _ ?_ ?_ ?_ <;> intros <;> rfl
+  refine' { .. } <;> intros <;> rfl
 
 instance : MonadExceptOf ε (ExceptCpsT ε m) where
   throw e  := fun _ _ k => k e

src/Init/Control/Lawful/Basic.lean

@@ -33,10 +33,6 @@ attribute [simp] id_map
 @[simp] theorem id_map' [Functor m] [LawfulFunctor m] (x : m α) : (fun a => a) <$> x = x :=
   id_map x
 
-@[simp] theorem Functor.map_map [Functor f] [LawfulFunctor f] (m : α → β) (g : β → γ) (x : f α) :
-    g <$> m <$> x = (fun a => g (m a)) <$> x :=
-  (comp_map _ _ _).symm
-
 /--
 The `Applicative` typeclass only contains the operations of an applicative functor.
 `LawfulApplicative` further asserts that these operations satisfy the laws of an applicative functor:
@@ -87,16 +83,12 @@ class LawfulMonad (m : Type u → Type v) [Monad m] extends LawfulApplicative m
   seq_assoc x g h := (by simp [← bind_pure_comp, ← bind_map, bind_assoc, pure_bind])
 
 export LawfulMonad (bind_pure_comp bind_map pure_bind bind_assoc)
-attribute [simp] pure_bind bind_assoc bind_pure_comp
+attribute [simp] pure_bind bind_assoc
 
 @[simp] theorem bind_pure [Monad m] [LawfulMonad m] (x : m α) : x >>= pure = x := by
   show x >>= (fun a => pure (id a)) = x
   rw [bind_pure_comp, id_map]
 
-/--
-Use `simp [← bind_pure_comp]` rather than `simp [map_eq_pure_bind]`,
-as `bind_pure_comp` is in the default simp set, so also using `map_eq_pure_bind` would cause a loop.
--/
 theorem map_eq_pure_bind [Monad m] [LawfulMonad m] (f : α → β) (x : m α) : f <$> x = x >>= fun a => pure (f a) := by
   rw [← bind_pure_comp]
 
@@ -117,24 +109,10 @@ theorem seq_eq_bind {α β : Type u} [Monad m] [LawfulMonad m] (mf : m (α →
 
 theorem seqRight_eq_bind [Monad m] [LawfulMonad m] (x : m α) (y : m β) : x *> y = x >>= fun _ => y := by
   rw [seqRight_eq]
-  simp only [map_eq_pure_bind, const, seq_eq_bind_map, bind_assoc, pure_bind, id_eq, bind_pure]
+  simp [map_eq_pure_bind, seq_eq_bind_map, const]
 
 theorem seqLeft_eq_bind [Monad m] [LawfulMonad m] (x : m α) (y : m β) : x <* y = x >>= fun a => y >>= fun _ => pure a := by
-  rw [seqLeft_eq]
-  simp only [map_eq_pure_bind, seq_eq_bind_map, bind_assoc, pure_bind, const_apply]
-
-@[simp] theorem map_bind [Monad m] [LawfulMonad m] (f : β → γ) (x : m α) (g : α → m β) :
-    f <$> (x >>= g) = x >>= fun a => f <$> g a := by
-  rw [← bind_pure_comp, LawfulMonad.bind_assoc]
-  simp [bind_pure_comp]
-
-@[simp] theorem bind_map_left [Monad m] [LawfulMonad m] (f : α → β) (x : m α) (g : β → m γ) :
-    ((f <$> x) >>= fun b => g b) = (x >>= fun a => g (f a)) := by
-  rw [← bind_pure_comp]
-  simp only [bind_assoc, pure_bind]
-
-@[simp] theorem Functor.map_unit [Monad m] [LawfulMonad m] {a : m PUnit} : (fun _ => PUnit.unit) <$> a = a := by
-  simp [map]
+  rw [seqLeft_eq]; simp [map_eq_pure_bind, seq_eq_bind_map]
 
 /--
 An alternative constructor for `LawfulMonad` which has more
@@ -175,7 +153,7 @@ namespace Id
 @[simp] theorem pure_eq (a : α) : (pure a : Id α) = a := rfl
 
 instance : LawfulMonad Id := by
-  refine LawfulMonad.mk' _ ?_ ?_ ?_ <;> intros <;> rfl
+  refine' { .. } <;> intros <;> rfl
 
 end Id
 
@@ -183,9 +161,9 @@ end Id
 
 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)
+  (pure_bind := fun x f => rfl)
+  (bind_assoc := fun x f g => by cases x <;> rfl)
+  (bind_pure_comp := fun f x => by cases x <;> rfl)
 
 instance : LawfulApplicative Option := inferInstance
 instance : LawfulFunctor Option := inferInstance

src/Init/Control/Lawful/Instances.lean

@@ -7,7 +7,6 @@ prelude
 import Init.Control.Lawful.Basic
 import Init.Control.Except
 import Init.Control.StateRef
-import Init.Ext
 
 open Function
 
@@ -15,7 +14,7 @@ open Function
 
 namespace ExceptT
 
-@[ext] theorem ext {x y : ExceptT ε m α} (h : x.run = y.run) : x = y := by
+theorem ext {x y : ExceptT ε m α} (h : x.run = y.run) : x = y := by
   simp [run] at h
   assumption
 
@@ -26,7 +25,7 @@ namespace ExceptT
 @[simp] theorem run_throw [Monad m] : run (throw e : ExceptT ε m β) = pure (Except.error e) := rfl
 
 @[simp] theorem run_bind_lift [Monad m] [LawfulMonad m] (x : m α) (f : α → ExceptT ε m β) : run (ExceptT.lift x >>= f : ExceptT ε m β) = x >>= fun a => run (f a) := by
-  simp [ExceptT.run, ExceptT.lift, bind, ExceptT.bind, ExceptT.mk, ExceptT.bindCont]
+  simp[ExceptT.run, ExceptT.lift, bind, ExceptT.bind, ExceptT.mk, ExceptT.bindCont, map_eq_pure_bind]
 
 @[simp] theorem bind_throw [Monad m] [LawfulMonad m] (f : α → ExceptT ε m β) : (throw e >>= f) = throw e := by
   simp [throw, throwThe, MonadExceptOf.throw, bind, ExceptT.bind, ExceptT.bindCont, ExceptT.mk]
@@ -44,7 +43,7 @@ theorem run_bind [Monad m] (x : ExceptT ε m α)
 
 @[simp] theorem run_map [Monad m] [LawfulMonad m] (f : α → β) (x : ExceptT ε m α)
     : (f <$> x).run = Except.map f <$> x.run := by
-  simp [Functor.map, ExceptT.map, ←bind_pure_comp]
+  simp [Functor.map, ExceptT.map, map_eq_pure_bind]
   apply bind_congr
   intro a; cases a <;> simp [Except.map]
 
@@ -63,7 +62,7 @@ protected theorem seqLeft_eq {α β ε : Type u} {m : Type u → Type v} [Monad
   intro
   | Except.error _ => simp
   | Except.ok _ =>
-    simp [←bind_pure_comp]; apply bind_congr; intro b;
+    simp [map_eq_pure_bind]; apply bind_congr; intro b;
     cases b <;> simp [comp, Except.map, const]
 
 protected theorem seqRight_eq [Monad m] [LawfulMonad m] (x : ExceptT ε m α) (y : ExceptT ε m β) : x *> y = const α id <$> x <*> y := by
@@ -85,19 +84,14 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (ExceptT ε m) where
   pure_bind      := by intros; apply ext; simp [run_bind]
   bind_assoc     := by intros; apply ext; simp [run_bind]; apply bind_congr; intro a; cases a <;> simp
 
-@[simp] theorem map_throw [Monad m] [LawfulMonad m] {α β : Type _} (f : α → β) (e : ε) :
-    f <$> (throw e : ExceptT ε m α) = (throw e : ExceptT ε m β) := by
-  simp only [ExceptT.instMonad, ExceptT.map, ExceptT.mk, throw, throwThe, MonadExceptOf.throw,
-    pure_bind]
-
 end ExceptT
 
 /-! # Except -/
 
 instance : LawfulMonad (Except ε) := LawfulMonad.mk'
   (id_map := fun x => by cases x <;> rfl)
-  (pure_bind := fun _ _ => rfl)
-  (bind_assoc := fun a _ _ => by cases a <;> rfl)
+  (pure_bind := fun a f => rfl)
+  (bind_assoc := fun a f g => by cases a <;> rfl)
 
 instance : LawfulApplicative (Except ε) := inferInstance
 instance : LawfulFunctor (Except ε) := inferInstance
@@ -106,7 +100,7 @@ instance : LawfulFunctor (Except ε) := inferInstance
 
 namespace ReaderT
 
-@[ext] theorem ext {x y : ReaderT ρ m α} (h : ∀ ctx, x.run ctx = y.run ctx) : x = y := by
+theorem ext {x y : ReaderT ρ m α} (h : ∀ ctx, x.run ctx = y.run ctx) : x = y := by
   simp [run] at h
   exact funext h
 
@@ -168,7 +162,7 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (StateRefT' ω σ m) :=
 
 namespace StateT
 
-@[ext] theorem ext {x y : StateT σ m α} (h : ∀ s, x.run s = y.run s) : x = y :=
+theorem ext {x y : StateT σ m α} (h : ∀ s, x.run s = y.run s) : x = y :=
   funext h
 
 @[simp] theorem run'_eq [Monad m] (x : StateT σ m α) (s : σ) : run' x s = (·.1) <$> run x s :=
@@ -181,7 +175,7 @@ namespace StateT
   simp [bind, StateT.bind, run]
 
 @[simp] 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
-  simp [Functor.map, StateT.map, run, ←bind_pure_comp]
+  simp [Functor.map, StateT.map, run, map_eq_pure_bind]
 
 @[simp] theorem run_get [Monad m] (s : σ)    : (get : StateT σ m σ).run s = pure (s, s) := rfl
 
@@ -216,13 +210,13 @@ theorem run_bind_lift {α σ : Type u} [Monad m] [LawfulMonad m] (x : m α) (f :
 
 theorem seqRight_eq [Monad m] [LawfulMonad m] (x : StateT σ m α) (y : StateT σ m β) : x *> y = const α id <$> x <*> y := by
   apply ext; intro s
-  simp [←bind_pure_comp, const]
+  simp [map_eq_pure_bind, const]
   apply bind_congr; intro p; cases p
   simp [Prod.eta]
 
 theorem seqLeft_eq [Monad m] [LawfulMonad m] (x : StateT σ m α) (y : StateT σ m β) : x <* y = const β <$> x <*> y := by
   apply ext; intro s
-  simp [←bind_pure_comp]
+  simp [map_eq_pure_bind]
 
 instance [Monad m] [LawfulMonad m] : LawfulMonad (StateT σ m) where
   id_map         := by intros; apply ext; intros; simp[Prod.eta]
@@ -230,7 +224,7 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (StateT σ m) where
   seqLeft_eq     := seqLeft_eq
   seqRight_eq    := seqRight_eq
   pure_seq       := by intros; apply ext; intros; simp
-  bind_pure_comp := by intros; apply ext; intros; simp
+  bind_pure_comp := by intros; apply ext; intros; simp; apply LawfulMonad.bind_pure_comp
   bind_map       := by intros; rfl
   pure_bind      := by intros; apply ext; intros; simp
   bind_assoc     := by intros; apply ext; intros; simp

src/Init/Control/StateCps.lean

@@ -35,7 +35,7 @@ instance : Monad (StateCpsT σ m) where
   bind x f := fun δ s k => x δ s fun a s => f a δ s k
 
 instance : LawfulMonad (StateCpsT σ m) := by
-  refine LawfulMonad.mk' _ ?_ ?_ ?_ <;> intros <;> rfl
+  refine' { .. } <;> intros <;> rfl
 
 @[always_inline]
 instance : MonadStateOf σ (StateCpsT σ m) where

src/Init/Control/StateRef.lean

@@ -6,7 +6,8 @@ Authors: Leonardo de Moura, Sebastian Ullrich
 The State monad transformer using IO references.
 -/
 prelude
-import Init.System.ST
+import Init.System.IO
+import Init.Control.State
 
 def StateRefT' (ω : Type) (σ : Type) (m : Type → Type) (α : Type) : Type := ReaderT (ST.Ref ω σ) m α
 

src/Init/Conv.lean

@@ -7,7 +7,6 @@ Notation for operators defined at Prelude.lean
 -/
 prelude
 import Init.Tactics
-import Init.Meta
 
 namespace Lean.Parser.Tactic.Conv
 
@@ -47,20 +46,12 @@ scoped syntax (name := withAnnotateState)
 /-- `skip` does nothing. -/
 syntax (name := skip) "skip" : conv
 
-/--
-Traverses into the left subterm of a binary operator.
-
-In general, for an `n`-ary operator, it traverses into the second to last argument.
-It is a synonym for `arg -2`.
--/
+/-- Traverses into the left subterm of a binary operator.
+(In general, for an `n`-ary operator, it traverses into the second to last argument.) -/
 syntax (name := lhs) "lhs" : conv
 
-/--
-Traverses into the right subterm of a binary operator.
-
-In general, for an `n`-ary operator, it traverses into the last argument.
-It is a synonym for `arg -1`.
--/
+/-- Traverses into the right subterm of a binary operator.
+(In general, for an `n`-ary operator, it traverses into the last argument.) -/
 syntax (name := rhs) "rhs" : conv
 
 /-- Traverses into the function of a (unary) function application.
@@ -83,17 +74,13 @@ subgoals for all the function arguments. For example, if the target is `f x y` t
 `congr` produces two subgoals, one for `x` and one for `y`. -/
 syntax (name := congr) "congr" : conv
 
-syntax argArg := "@"? "-"? num
-
 /--
 * `arg i` traverses into the `i`'th argument of the target. For example if the
   target is `f a b c d` then `arg 1` traverses to `a` and `arg 3` traverses to `c`.
-  The index may be negative; `arg -1` traverses into the last argument,
-  `arg -2` into the second-to-last argument, and so on.
 * `arg @i` is the same as `arg i` but it counts all arguments instead of just the
   explicit arguments.
 * `arg 0` traverses into the function. If the target is `f a b c d`, `arg 0` traverses into `f`. -/
-syntax (name := arg) "arg " argArg : conv
+syntax (name := arg) "arg " "@"? num : conv
 
 /-- `ext x` traverses into a binder (a `fun x => e` or `∀ x, e` expression)
 to target `e`, introducing name `x` in the process. -/
@@ -110,18 +97,11 @@ Users should prefer `unfold` for unfolding definitions. -/
 syntax (name := delta) "delta" (ppSpace colGt ident)+ : conv
 
 /--
-* `unfold id` unfolds all occurrences of definition `id` in the target.
+* `unfold foo` unfolds all occurrences of `foo` in the target.
 * `unfold id1 id2 ...` is equivalent to `unfold id1; unfold id2; ...`.
-
-Definitions can be either global or local definitions.
-
-For non-recursive global definitions, this tactic is identical to `delta`.
-For recursive global definitions, it uses the "unfolding lemma" `id.eq_def`,
-which is generated for each recursive definition, to unfold according to the recursive definition given by the user.
-Only one level of unfolding is performed, in contrast to `simp only [id]`, which unfolds definition `id` recursively.
-
-This is the `conv` version of the `unfold` tactic.
--/
+Like the `unfold` tactic, this uses equational lemmas for the chosen definition
+to rewrite the target. For recursive definitions,
+only one layer of unfolding is performed. -/
 syntax (name := unfold) "unfold" (ppSpace colGt ident)+ : conv
 
 /--
@@ -143,11 +123,11 @@ For example, if we are searching for `f _` in `f (f a) = f b`:
 syntax (name := pattern) "pattern " (occs)? term : conv
 
 /-- `rw [thm]` rewrites the target using `thm`. See the `rw` tactic for more information. -/
-syntax (name := rewrite) "rewrite" optConfig rwRuleSeq : conv
+syntax (name := rewrite) "rewrite" (config)? rwRuleSeq : conv
 
 /-- `simp [thm]` performs simplification using `thm` and marked `@[simp]` lemmas.
 See the `simp` tactic for more information. -/
-syntax (name := simp) "simp" optConfig (discharger)? (&" only")?
+syntax (name := simp) "simp" (config)? (discharger)? (&" only")?
   (" [" withoutPosition((simpStar <|> simpErase <|> simpLemma),*) "]")? : conv
 
 /--
@@ -164,7 +144,7 @@ example (a : Nat): (0 + 0) = a - a := by
     rw [← Nat.sub_self a]
 ```
 -/
-syntax (name := dsimp) "dsimp" optConfig (discharger)? (&" only")?
+syntax (name := dsimp) "dsimp" (config)? (discharger)? (&" only")?
   (" [" withoutPosition((simpErase <|> simpLemma),*) "]")? : conv
 
 /-- `simp_match` simplifies match expressions. For example,
@@ -260,12 +240,12 @@ macro (name := failIfSuccess) tk:"fail_if_success " s:convSeq : conv =>
 
 /-- `rw [rules]` applies the given list of rewrite rules to the target.
 See the `rw` tactic for more information. -/
-macro "rw" c:optConfig s:rwRuleSeq : conv => `(conv| rewrite $c:optConfig $s)
+macro "rw" c:(config)? s:rwRuleSeq : conv => `(conv| rewrite $[$c]? $s)
 
-/-- `erw [rules]` is a shorthand for `rw (transparency := .default) [rules]`.
+/-- `erw [rules]` is a shorthand for `rw (config := { transparency := .default }) [rules]`.
 This does rewriting up to unfolding of regular definitions (by comparison to regular `rw`
 which only unfolds `@[reducible]` definitions). -/
-macro "erw" c:optConfig s:rwRuleSeq : conv => `(conv| rw $[$(getConfigItems c)]* (transparency := .default) $s:rwRuleSeq)
+macro "erw" s:rwRuleSeq : conv => `(conv| rw (config := { transparency := .default }) $s)
 
 /-- `args` traverses into all arguments. Synonym for `congr`. -/
 macro "args" : conv => `(conv| congr)
@@ -276,7 +256,7 @@ macro "right" : conv => `(conv| rhs)
 /-- `intro` traverses into binders. Synonym for `ext`. -/
 macro "intro" xs:(ppSpace colGt ident)* : conv => `(conv| ext $xs*)
 
-syntax enterArg := ident <|> argArg
+syntax enterArg := ident <|> ("@"? num)
 
 /-- `enter [arg, ...]` is a compact way to describe a path to a subterm.
 It is a shorthand for other conv tactics as follows:
@@ -285,7 +265,12 @@ It is a shorthand for other conv tactics as follows:
 * `enter [x]` (where `x` is an identifier) is equivalent to `ext x`.
 For example, given the target `f (g a (fun x => x b))`, `enter [1, 2, x, 1]`
 will traverse to the subterm `b`. -/
-syntax (name := enter) "enter" " [" withoutPosition(enterArg,+) "]" : conv
+syntax "enter" " [" withoutPosition(enterArg,+) "]" : conv
+macro_rules
+  | `(conv| enter [$i:num]) => `(conv| arg $i)
+  | `(conv| enter [@$i]) => `(conv| arg @$i)
+  | `(conv| enter [$id:ident]) => `(conv| ext $id)
+  | `(conv| enter [$arg, $args,*]) => `(conv| (enter [$arg]; enter [$args,*]))
 
 /-- The `apply thm` conv tactic is the same as `apply thm` the tactic.
 There are no restrictions on `thm`, but strange results may occur if `thm`

src/Init/Core.lean

@@ -36,17 +36,6 @@ and `flip (·<·)` is the greater-than relation.
 
 theorem Function.comp_def {α β δ} (f : β → δ) (g : α → β) : f ∘ g = fun x => f (g x) := rfl
 
-@[simp] theorem Function.const_comp {f : α → β} {c : γ} :
-    (Function.const β c ∘ f) = Function.const α c := by
-  rfl
-@[simp] theorem Function.comp_const {f : β → γ} {b : β} :
-    (f ∘ Function.const α b) = Function.const α (f b) := by
-  rfl
-@[simp] theorem Function.true_comp {f : α → β} : ((fun _ => true) ∘ f) = fun _ => true := by
-  rfl
-@[simp] theorem Function.false_comp {f : α → β} : ((fun _ => false) ∘ f) = fun _ => false := by
-  rfl
-
 attribute [simp] namedPattern
 
 /--
@@ -165,23 +154,9 @@ inductive PSum (α : Sort u) (β : Sort v) where
 
 @[inherit_doc] infixr:30 " ⊕' " => PSum
 
-/--
-`PSum α β` is inhabited if `α` is inhabited.
-This is not an instance to avoid non-canonical instances.
--/
-@[reducible] def  PSum.inhabitedLeft {α β} [Inhabited α] : Inhabited (PSum α β) := ⟨PSum.inl default⟩
+instance {α β} [Inhabited α] : Inhabited (PSum α β) := ⟨PSum.inl default⟩
 
-/--
-`PSum α β` is inhabited if `β` is inhabited.
-This is not an instance to avoid non-canonical instances.
--/
-@[reducible] def PSum.inhabitedRight {α β} [Inhabited β] : Inhabited (PSum α β) := ⟨PSum.inr default⟩
-
-instance PSum.nonemptyLeft [h : Nonempty α] : Nonempty (PSum α β) :=
-  Nonempty.elim h (fun a => ⟨PSum.inl a⟩)
-
-instance PSum.nonemptyRight [h : Nonempty β] : Nonempty (PSum α β) :=
-  Nonempty.elim h (fun b => ⟨PSum.inr b⟩)
+instance {α β} [Inhabited β] : Inhabited (PSum α β) := ⟨PSum.inr default⟩
 
 /--
 `Sigma β`, also denoted `Σ a : α, β a` or `(a : α) × β a`, is the type of dependent pairs
@@ -324,6 +299,7 @@ class ForIn' (m : Type u₁ → Type u₂) (ρ : Type u) (α : outParam (Type v)
 
 export ForIn' (forIn')
 
+
 /--
 Auxiliary type used to compile `do` notation. It is used when compiling a do block
 nested inside a combinator like `tryCatch`. It encodes the possible ways the
@@ -498,8 +474,6 @@ class LawfulSingleton (α : Type u) (β : Type v) [EmptyCollection β] [Insert
   insert_emptyc_eq (x : α) : (insert x ∅ : β) = singleton x
 export LawfulSingleton (insert_emptyc_eq)
 
-attribute [simp] insert_emptyc_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 }`. -/
@@ -727,7 +701,7 @@ theorem Ne.elim (h : a ≠ b) : a = b → False := h
 
 theorem Ne.irrefl (h : a ≠ a) : False := h rfl
 
-@[symm] theorem Ne.symm (h : a ≠ b) : b ≠ a := fun h₁ => h (h₁.symm)
+theorem Ne.symm (h : a ≠ b) : b ≠ a := fun h₁ => h (h₁.symm)
 
 theorem ne_comm {α} {a b : α} : a ≠ b ↔ b ≠ a := ⟨Ne.symm, Ne.symm⟩
 
@@ -780,7 +754,7 @@ noncomputable def HEq.elim {α : Sort u} {a : α} {p : α → Sort v} {b : α} (
 theorem HEq.subst {p : (T : Sort u) → T → Prop} (h₁ : HEq a b) (h₂ : p α a) : p β b :=
   HEq.ndrecOn h₁ h₂
 
-@[symm] theorem HEq.symm (h : HEq a b) : HEq b a :=
+theorem HEq.symm (h : HEq a b) : HEq b a :=
   h.rec (HEq.refl a)
 
 theorem heq_of_eq (h : a = a') : HEq a a' :=
@@ -813,16 +787,15 @@ theorem cast_heq {α β : Sort u} : (h : α = β) → (a : α) → HEq (cast h a
 
 variable {a b c d : Prop}
 
-theorem iff_iff_implies_and_implies {a b : Prop} : (a ↔ b) ↔ (a → b) ∧ (b → a) :=
+theorem iff_iff_implies_and_implies (a b : Prop) : (a ↔ b) ↔ (a → b) ∧ (b → a) :=
   Iff.intro (fun h => And.intro h.mp h.mpr) (fun h => Iff.intro h.left h.right)
 
-@[refl] theorem Iff.refl (a : Prop) : a ↔ a :=
+theorem Iff.refl (a : Prop) : a ↔ a :=
   Iff.intro (fun h => h) (fun h => h)
 
 protected theorem Iff.rfl {a : Prop} : a ↔ a :=
   Iff.refl a
 
--- And, also for backward compatibility, we try `Iff.rfl.` using `exact` (see #5366)
 macro_rules | `(tactic| rfl) => `(tactic| exact Iff.rfl)
 
 theorem Iff.of_eq (h : a = b) : a ↔ b := h ▸ Iff.rfl
@@ -837,18 +810,15 @@ instance : Trans Iff Iff Iff where
 theorem Eq.comm {a b : α} : a = b ↔ b = a := Iff.intro Eq.symm Eq.symm
 theorem eq_comm {a b : α} : a = b ↔ b = a := Eq.comm
 
-theorem HEq.comm {a : α} {b : β} : HEq a b ↔ HEq b a := Iff.intro HEq.symm HEq.symm
-theorem heq_comm {a : α} {b : β} : HEq a b ↔ HEq b a := HEq.comm
-
-@[symm] theorem Iff.symm (h : a ↔ b) : b ↔ a := Iff.intro h.mpr h.mp
+theorem Iff.symm (h : a ↔ b) : b ↔ a := Iff.intro h.mpr h.mp
 theorem Iff.comm: (a ↔ b) ↔ (b ↔ a) := Iff.intro Iff.symm Iff.symm
 theorem iff_comm : (a ↔ b) ↔ (b ↔ a) := Iff.comm
 
-@[symm] theorem And.symm : a ∧ b → b ∧ a := fun ⟨ha, hb⟩ => ⟨hb, ha⟩
+theorem And.symm : a ∧ b → b ∧ a := fun ⟨ha, hb⟩ => ⟨hb, ha⟩
 theorem And.comm : a ∧ b ↔ b ∧ a := Iff.intro And.symm And.symm
 theorem and_comm : a ∧ b ↔ b ∧ a := And.comm
 
-@[symm] theorem Or.symm : a ∨ b → b ∨ a := .rec .inr .inl
+theorem Or.symm : a ∨ b → b ∨ a := .rec .inr .inl
 theorem Or.comm : a ∨ b ↔ b ∨ a := Iff.intro Or.symm Or.symm
 theorem or_comm : a ∨ b ↔ b ∨ a := Or.comm
 
@@ -861,21 +831,16 @@ theorem Exists.elim {α : Sort u} {p : α → Prop} {b : Prop}
 
 /-! # Decidable -/
 
-@[simp] theorem decide_true (h : Decidable True) : @decide True h = true :=
+theorem decide_true_eq_true (h : Decidable True) : @decide True h = true :=
   match h with
   | isTrue _  => rfl
   | isFalse h => False.elim <| h ⟨⟩
 
-@[simp] theorem decide_false (h : Decidable False) : @decide False h = false :=
+theorem decide_false_eq_false (h : Decidable False) : @decide False h = false :=
   match h with
   | isFalse _ => rfl
   | isTrue h  => False.elim h
 
-set_option linter.missingDocs false in
-@[deprecated decide_true (since := "2024-11-05")] abbrev decide_true_eq_true := decide_true
-set_option linter.missingDocs false in
-@[deprecated decide_false (since := "2024-11-05")] abbrev decide_false_eq_false := decide_false
-
 /-- Similar to `decide`, but uses an explicit instance -/
 @[inline] def toBoolUsing {p : Prop} (d : Decidable p) : Bool :=
   decide (h := d)
@@ -918,7 +883,7 @@ theorem byContradiction [dec : Decidable p] (h : ¬p → False) : p :=
 theorem of_not_not [Decidable p] : ¬ ¬ p → p :=
   fun hnn => byContradiction (fun hn => absurd hn hnn)
 
-theorem not_and_iff_or_not {p q : Prop} [d₁ : Decidable p] [d₂ : Decidable q] : ¬ (p ∧ q) ↔ ¬ p ∨ ¬ q :=
+theorem not_and_iff_or_not (p q : Prop) [d₁ : Decidable p] [d₂ : Decidable q] : ¬ (p ∧ q) ↔ ¬ p ∨ ¬ q :=
   Iff.intro
     (fun h => match d₁, d₂ with
       | isTrue h₁,  isTrue h₂   => absurd (And.intro h₁ h₂) h
@@ -1137,17 +1102,9 @@ inductive Relation.TransGen {α : Sort u} (r : α → α → Prop) : α → α
 /-- Deprecated synonym for `Relation.TransGen`. -/
 @[deprecated Relation.TransGen (since := "2024-07-16")] abbrev TC := @Relation.TransGen
 
-theorem Relation.TransGen.trans {α : Sort u} {r : α → α → Prop} {a b c} :
-    TransGen r a b → TransGen r b c → TransGen r a c := by
-  intro hab hbc
-  induction hbc with
-  | single h => exact TransGen.tail hab h
-  | tail _ h ih => exact TransGen.tail ih h
-
 /-! # Subtype -/
 
 namespace Subtype
-
 theorem existsOfSubtype {α : Type u} {p : α → Prop} : { x // p x } → Exists (fun x => p x)
   | ⟨a, h⟩ => ⟨a, h⟩
 
@@ -1172,20 +1129,12 @@ end Subtype
 section
 variable {α : Type u} {β : Type v}
 
-/-- This is not an instance to avoid non-canonical instances. -/
-@[reducible] def Sum.inhabitedLeft [Inhabited α] : Inhabited (Sum α β) where
+instance Sum.inhabitedLeft [Inhabited α] : Inhabited (Sum α β) where
   default := Sum.inl default
 
-/-- This is not an instance to avoid non-canonical instances. -/
-@[reducible] def Sum.inhabitedRight [Inhabited β] : Inhabited (Sum α β) where
+instance Sum.inhabitedRight [Inhabited β] : Inhabited (Sum α β) where
   default := Sum.inr default
 
-instance Sum.nonemptyLeft [h : Nonempty α] : Nonempty (Sum α β) :=
-  Nonempty.elim h (fun a => ⟨Sum.inl a⟩)
-
-instance Sum.nonemptyRight [h : Nonempty β] : Nonempty (Sum α β) :=
-  Nonempty.elim h (fun b => ⟨Sum.inr b⟩)
-
 instance {α : Type u} {β : Type v} [DecidableEq α] [DecidableEq β] : DecidableEq (Sum α β) := fun a b =>
   match a, b with
   | Sum.inl a, Sum.inl b =>
@@ -1201,21 +1150,6 @@ end
 
 /-! # Product -/
 
-instance [h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (α × β) :=
-  Nonempty.elim h1 fun x =>
-    Nonempty.elim h2 fun y =>
-      ⟨(x, y)⟩
-
-instance [h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (MProd α β) :=
-  Nonempty.elim h1 fun x =>
-    Nonempty.elim h2 fun y =>
-      ⟨⟨x, y⟩⟩
-
-instance [h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (PProd α β) :=
-  Nonempty.elim h1 fun x =>
-    Nonempty.elim h2 fun y =>
-      ⟨⟨x, y⟩⟩
-
 instance [Inhabited α] [Inhabited β] : Inhabited (α × β) where
   default := (default, default)
 
@@ -1267,13 +1201,9 @@ def Prod.map {α₁ : Type u₁} {α₂ : Type u₂} {β₁ : Type v₁} {β₂
 
 /-! # Dependent products -/
 
-theorem Exists.of_psigma_prop {α : Sort u} {p : α → Prop} : (PSigma (fun x => p x)) → Exists (fun x => p x)
+theorem ex_of_PSigma {α : Type u} {p : α → Prop} : (PSigma (fun x => p x)) → Exists (fun x => p x)
   | ⟨x, hx⟩ => ⟨x, hx⟩
 
-@[deprecated Exists.of_psigma_prop (since := "2024-07-27")]
-theorem ex_of_PSigma {α : Type u} {p : α → Prop} : (PSigma (fun x => p x)) → Exists (fun x => p x) :=
-  Exists.of_psigma_prop
-
 protected theorem PSigma.eta {α : Sort u} {β : α → Sort v} {a₁ a₂ : α} {b₁ : β a₁} {b₂ : β a₂}
     (h₁ : a₁ = a₂) (h₂ : Eq.ndrec b₁ h₁ = b₂) : PSigma.mk a₁ b₁ = PSigma.mk a₂ b₂ := by
   subst h₁
@@ -1389,7 +1319,6 @@ gen_injective_theorems% Except
 gen_injective_theorems% EStateM.Result
 gen_injective_theorems% Lean.Name
 gen_injective_theorems% Lean.Syntax
-gen_injective_theorems% BitVec
 
 theorem Nat.succ.inj {m n : Nat} : m.succ = n.succ → m = n :=
   fun x => Nat.noConfusion x id
@@ -1397,7 +1326,7 @@ theorem Nat.succ.inj {m n : Nat} : m.succ = n.succ → m = n :=
 theorem Nat.succ.injEq (u v : Nat) : (u.succ = v.succ) = (u = v) :=
   Eq.propIntro Nat.succ.inj (congrArg Nat.succ)
 
-@[simp] theorem beq_iff_eq [BEq α] [LawfulBEq α] {a b : α} : a == b ↔ a = b :=
+@[simp] theorem beq_iff_eq [BEq α] [LawfulBEq α] (a b : α) : a == b ↔ a = b :=
   ⟨eq_of_beq, by intro h; subst h; exact LawfulBEq.rfl⟩
 
 /-! # Prop lemmas -/
@@ -1462,7 +1391,7 @@ theorem false_of_true_eq_false  (h : True = False) : False := false_of_true_iff_
 
 theorem true_eq_false_of_false : False → (True = False) := False.elim
 
-theorem iff_def  : (a ↔ b) ↔ (a → b) ∧ (b → a) := iff_iff_implies_and_implies
+theorem iff_def  : (a ↔ b) ↔ (a → b) ∧ (b → a) := iff_iff_implies_and_implies a b
 theorem iff_def' : (a ↔ b) ↔ (b → a) ∧ (a → b) := Iff.trans iff_def And.comm
 
 theorem true_iff_false : (True ↔ False) ↔ False := iff_false_intro (·.mp  True.intro)
@@ -1490,7 +1419,7 @@ theorem imp_true_iff (α : Sort u) : (α → True) ↔ True := iff_true_intro (f
 
 theorem false_imp_iff (a : Prop) : (False → a) ↔ True := iff_true_intro False.elim
 
-theorem true_imp_iff {α : Prop} : (True → α) ↔ α := imp_iff_right True.intro
+theorem true_imp_iff (α : Prop) : (True → α) ↔ α := imp_iff_right True.intro
 
 @[simp high] theorem imp_self : (a → a) ↔ True := iff_true_intro id
 
@@ -1610,13 +1539,13 @@ so you should consider the simpler versions if they apply:
 * `Quot.recOnSubsingleton`, when the target type is a `Subsingleton`
 * `Quot.hrecOn`, which uses `HEq (f a) (f b)` instead of a `sound p ▸ f a = f b` assummption
 -/
-@[elab_as_elim] protected abbrev rec
+protected abbrev rec
     (f : (a : α) → motive (Quot.mk r a))
     (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b)
     (q : Quot r) : motive q :=
   Eq.ndrecOn (Quot.liftIndepPr1 f h q) ((lift (Quot.indep f) (Quot.indepCoherent f h) q).2)
 
-@[inherit_doc Quot.rec, elab_as_elim] protected abbrev recOn
+@[inherit_doc Quot.rec] protected abbrev recOn
     (q : Quot r)
     (f : (a : α) → motive (Quot.mk r a))
     (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b)
@@ -1627,7 +1556,7 @@ so you should consider the simpler versions if they apply:
 Dependent induction principle for a quotient, when the target type is a `Subsingleton`.
 In this case the quotient's side condition is trivial so any function can be lifted.
 -/
-@[elab_as_elim] protected abbrev recOnSubsingleton
+protected abbrev recOnSubsingleton
     [h : (a : α) → Subsingleton (motive (Quot.mk r a))]
     (q : Quot r)
     (f : (a : α) → motive (Quot.mk r a))
@@ -1696,7 +1625,7 @@ protected theorem ind {α : Sort u} {s : Setoid α} {motive : Quotient s → Pro
 
 /--
 The analogue of `Quot.liftOn`: if `f : α → β` respects the equivalence relation `≈`,
-then it lifts to a function on `Quotient s` such that `liftOn (mk a) f h = f a`.
+then it lifts to a function on `Quotient s` such that `lift (mk a) f h = f a`.
 -/
 protected abbrev liftOn {α : Sort u} {β : Sort v} {s : Setoid α} (q : Quotient s) (f : α → β) (c : (a b : α) → a ≈ b → f a = f b) : β :=
   Quot.liftOn q f c
@@ -1869,8 +1798,7 @@ section
 variable {α : Type u}
 variable (r : α → α → Prop)
 
-instance Quotient.decidableEq {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)]
-    : DecidableEq (Quotient s) :=
+instance {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)] : DecidableEq (Quotient s) :=
   fun (q₁ q₂ : Quotient s) =>
     Quotient.recOnSubsingleton₂ q₁ q₂
       fun a₁ a₂ =>
@@ -1902,8 +1830,7 @@ theorem funext {α : Sort u} {β : α → Sort v} {f g : (x : α) → β x}
   show extfunApp (Quot.mk eqv f) = extfunApp (Quot.mk eqv g)
   exact congrArg extfunApp (Quot.sound h)
 
-instance Pi.instSubsingleton {α : Sort u} {β : α → Sort v} [∀ a, Subsingleton (β a)] :
-    Subsingleton (∀ a, β a) where
+instance {α : Sort u} {β : α → Sort v} [∀ a, Subsingleton (β a)] : Subsingleton (∀ a, β a) where
   allEq f g := funext fun a => Subsingleton.elim (f a) (g a)
 
 /-! # Squash -/
@@ -1922,12 +1849,12 @@ represents an element of `Squash α` the same as `α` itself
 `Squash.lift` will extract a value in any subsingleton `β` from a function on `α`,
 while `Nonempty.rec` can only do the same when `β` is a proposition.
 -/
-def Squash (α : Sort u) := Quot (fun (_ _ : α) => True)
+def Squash (α : Type u) := Quot (fun (_ _ : α) => True)
 
 /-- The canonical quotient map into `Squash α`. -/
-def Squash.mk {α : Sort u} (x : α) : Squash α := Quot.mk _ x
+def Squash.mk {α : Type u} (x : α) : Squash α := Quot.mk _ x
 
-theorem Squash.ind {α : Sort u} {motive : Squash α → Prop} (h : ∀ (a : α), motive (Squash.mk a)) : ∀ (q : Squash α), motive q :=
+theorem Squash.ind {α : Type u} {motive : Squash α → Prop} (h : ∀ (a : α), motive (Squash.mk a)) : ∀ (q : Squash α), motive q :=
   Quot.ind h
 
 /-- If `β` is a subsingleton, then a function `α → β` lifts to `Squash α → β`. -/
@@ -1941,6 +1868,15 @@ instance : Subsingleton (Squash α) where
     apply Quot.sound
     trivial
 
+/-! # Relations -/
+
+/--
+`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
+-/
+class Antisymm {α : Sort u} (r : α → α → Prop) : Prop where
+  /-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
+  antisymm {a b : α} : r a b → r b a → a = b
+
 namespace Lean
 /-! # Kernel reduction hints -/
 
@@ -2057,7 +1993,7 @@ class IdempotentOp (op : α → α → α) : Prop where
 `LeftIdentify op o` indicates `o` is a left identity of `op`.
 
 This class does not require a proof that `o` is an identity, and
-is used primarily for inferring the identity using class resolution.
+is used primarily for infering the identity using class resoluton.
 -/
 class LeftIdentity (op : α → β → β) (o : outParam α) : Prop
 
@@ -2073,7 +2009,7 @@ class LawfulLeftIdentity (op : α → β → β) (o : outParam α) extends LeftI
 `RightIdentify op o` indicates `o` is a right identity `o` of `op`.
 
 This class does not require a proof that `o` is an identity, and is used
-primarily for inferring the identity using class resolution.
+primarily for infering the identity using class resoluton.
 -/
 class RightIdentity (op : α → β → α) (o : outParam β) : Prop
 
@@ -2089,7 +2025,7 @@ class LawfulRightIdentity (op : α → β → α) (o : outParam β) extends Righ
 `Identity op o` indicates `o` is a left and right identity of `op`.
 
 This class does not require a proof that `o` is an identity, and is used
-primarily for inferring the identity using class resolution.
+primarily for infering the identity using class resoluton.
 -/
 class Identity (op : α → α → α) (o : outParam α) extends LeftIdentity op o, RightIdentity op o : Prop
 
@@ -2116,14 +2052,4 @@ instance : Commutative Or := ⟨fun _ _ => propext or_comm⟩
 instance : Commutative And := ⟨fun _ _ => propext and_comm⟩
 instance : Commutative Iff := ⟨fun _ _ => propext iff_comm⟩
 
-/--
-`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
--/
-class Antisymm (r : α → α → Prop) : Prop where
-  /-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
-  antisymm {a b : α} : r a b → r b a → a = b
-
-@[deprecated Antisymm (since := "2024-10-16"), inherit_doc Antisymm]
-abbrev _root_.Antisymm (r : α → α → Prop) : Prop := Std.Antisymm r
-
 end Std

src/Init/Data.lean

@@ -19,7 +19,6 @@ import Init.Data.ByteArray
 import Init.Data.FloatArray
 import Init.Data.Fin
 import Init.Data.UInt
-import Init.Data.SInt
 import Init.Data.Float
 import Init.Data.Option
 import Init.Data.Ord
@@ -34,12 +33,6 @@ import Init.Data.Prod
 import Init.Data.AC
 import Init.Data.Queue
 import Init.Data.Channel
+import Init.Data.Cast
 import Init.Data.Sum
 import Init.Data.BEq
-import Init.Data.Subtype
-import Init.Data.ULift
-import Init.Data.PLift
-import Init.Data.Zero
-import Init.Data.NeZero
-import Init.Data.Function
-import Init.Data.RArray

src/Init/Data/AC.lean

@@ -6,7 +6,7 @@ Authors: Dany Fabian
 
 prelude
 import Init.Classical
-import Init.ByCases
+import Init.Data.List
 
 namespace Lean.Data.AC
 inductive Expr
@@ -260,7 +260,7 @@ theorem Context.evalList_sort (ctx : Context α) (h : ContextInformation.isComm
     simp [ContextInformation.isComm, Option.isSome] at h
     match h₂ : ctx.comm with
     | none =>
-      simp [h₂] at h
+      simp only [h₂] at h
     | some val =>
       simp [h₂] at h
       exact val.down

src/Init/Data/Array.lean

@@ -14,8 +14,3 @@ import Init.Data.Array.Attach
 import Init.Data.Array.BasicAux
 import Init.Data.Array.Lemmas
 import Init.Data.Array.TakeDrop
-import Init.Data.Array.Bootstrap
-import Init.Data.Array.GetLit
-import Init.Data.Array.MapIdx
-import Init.Data.Array.Set
-import Init.Data.Array.Monadic

src/Init/Data/Array/Attach.lean

@@ -5,22 +5,10 @@ Authors: Joachim Breitner, Mario Carneiro
 -/
 prelude
 import Init.Data.Array.Mem
-import Init.Data.Array.Lemmas
 import Init.Data.List.Attach
 
 namespace Array
 
-/--
-`O(n)`. Partial map. If `f : Π a, P a → β` is a partial function defined on
-`a : α` satisfying `P`, then `pmap f l h` is essentially the same as `map f l`
-but is defined only when all members of `l` satisfy `P`, using the proof
-to apply `f`.
-
-We replace this at runtime with a more efficient version via the `csimp` lemma `pmap_eq_pmapImpl`.
--/
-def pmap {P : α → Prop} (f : ∀ a, P a → β) (l : Array α) (H : ∀ a ∈ l, P a) : Array β :=
-  (l.toList.pmap f (fun a m => H a (mem_def.mpr m))).toArray
-
 /--
 Unsafe implementation of `attachWith`, taking advantage of the fact that the representation of
 `Array {x // P x}` is the same as the input `Array α`.
@@ -32,552 +20,10 @@ Unsafe implementation of `attachWith`, taking advantage of the fact that the rep
   with the same elements but in the type `{x // P x}`. -/
 @[implemented_by attachWithImpl] def attachWith
     (xs : Array α) (P : α → Prop) (H : ∀ x ∈ xs, P x) : Array {x // P x} :=
-  ⟨xs.toList.attachWith P fun x h => H x (Array.Mem.mk h)⟩
+  ⟨xs.data.attachWith P fun x h => H x (Array.Mem.mk h)⟩
 
 /-- `O(1)`. "Attach" the proof that the elements of `xs` are in `xs` to produce a new array
   with the same elements but in the type `{x // x ∈ xs}`. -/
 @[inline] def attach (xs : Array α) : Array {x // x ∈ xs} := xs.attachWith _ fun _ => id
 
-@[simp] theorem _root_.List.attachWith_toArray {l : List α} {P : α → Prop} {H : ∀ x ∈ l.toArray, P x} :
-    l.toArray.attachWith P H = (l.attachWith P (by simpa using H)).toArray := by
-  simp [attachWith]
-
-@[simp] theorem _root_.List.attach_toArray {l : List α} :
-    l.toArray.attach = (l.attachWith (· ∈ l.toArray) (by simp)).toArray := by
-  simp [attach]
-
-@[simp] theorem _root_.List.pmap_toArray {l : List α} {P : α → Prop} {f : ∀ a, P a → β} {H : ∀ a ∈ l.toArray, P a} :
-    l.toArray.pmap f H = (l.pmap f (by simpa using H)).toArray := by
-  simp [pmap]
-
-@[simp] theorem toList_attachWith {l : Array α} {P : α → Prop} {H : ∀ x ∈ l, P x} :
-   (l.attachWith P H).toList = l.toList.attachWith P (by simpa [mem_toList] using H) := by
-  simp [attachWith]
-
-@[simp] theorem toList_attach {α : Type _} {l : Array α} :
-    l.attach.toList = l.toList.attachWith (· ∈ l) (by simp [mem_toList]) := by
-  simp [attach]
-
-@[simp] theorem toList_pmap {l : Array α} {P : α → Prop} {f : ∀ a, P a → β} {H : ∀ a ∈ l, P a} :
-    (l.pmap f H).toList = l.toList.pmap f (fun a m => H a (mem_def.mpr m)) := by
-  simp [pmap]
-
-/-- Implementation of `pmap` using the zero-copy version of `attach`. -/
-@[inline] private def pmapImpl {P : α → Prop} (f : ∀ a, P a → β) (l : Array α) (H : ∀ a ∈ l, P a) :
-    Array β := (l.attachWith _ H).map fun ⟨x, h'⟩ => f x h'
-
-@[csimp] private theorem pmap_eq_pmapImpl : @pmap = @pmapImpl := by
-  funext α β p f L h'
-  cases L
-  simp only [pmap, pmapImpl, List.attachWith_toArray, List.map_toArray, mk.injEq, List.map_attachWith]
-  apply List.pmap_congr_left
-  intro a m h₁ h₂
-  congr
-
-@[simp] theorem pmap_empty {P : α → Prop} (f : ∀ a, P a → β) : pmap f #[] (by simp) = #[] := rfl
-
-@[simp] theorem pmap_push {P : α → Prop} (f : ∀ a, P a → β) (a : α) (l : Array α) (h : ∀ b ∈ l.push a, P b) :
-    pmap f (l.push a) h =
-      (pmap f l (fun a m => by simp at h; exact h a (.inl m))).push (f a (h a (by simp))) := by
-  simp [pmap]
-
-@[simp] theorem attach_empty : (#[] : Array α).attach = #[] := rfl
-
-@[simp] theorem attachWith_empty {P : α → Prop} (H : ∀ x ∈ #[], P x) : (#[] : Array α).attachWith P H = #[] := rfl
-
-@[simp] theorem _root_.List.attachWith_mem_toArray {l : List α} :
-    l.attachWith (fun x => x ∈ l.toArray) (fun x h => by simpa using h) =
-      l.attach.map fun ⟨x, h⟩ => ⟨x, by simpa using h⟩ := by
-  simp only [List.attachWith, List.attach, List.map_pmap]
-  apply List.pmap_congr_left
-  simp
-
-@[simp]
-theorem pmap_eq_map (p : α → Prop) (f : α → β) (l : Array α) (H) :
-    @pmap _ _ p (fun a _ => f a) l H = map f l := by
-  cases l; simp
-
-theorem pmap_congr_left {p q : α → Prop} {f : ∀ a, p a → β} {g : ∀ a, q a → β} (l : Array α) {H₁ H₂}
-    (h : ∀ a ∈ l, ∀ (h₁ h₂), f a h₁ = g a h₂) : pmap f l H₁ = pmap g l H₂ := by
-  cases l
-  simp only [mem_toArray] at h
-  simp only [List.pmap_toArray, mk.injEq]
-  rw [List.pmap_congr_left _ h]
-
-theorem map_pmap {p : α → Prop} (g : β → γ) (f : ∀ a, p a → β) (l H) :
-    map g (pmap f l H) = pmap (fun a h => g (f a h)) l H := by
-  cases l
-  simp [List.map_pmap]
-
-theorem pmap_map {p : β → Prop} (g : ∀ b, p b → γ) (f : α → β) (l H) :
-    pmap g (map f l) H = pmap (fun a h => g (f a) h) l fun _ h => H _ (mem_map_of_mem _ h) := by
-  cases l
-  simp [List.pmap_map]
-
-theorem attach_congr {l₁ l₂ : Array α} (h : l₁ = l₂) :
-    l₁.attach = l₂.attach.map (fun x => ⟨x.1, h ▸ x.2⟩) := by
-  subst h
-  simp
-
-theorem attachWith_congr {l₁ l₂ : Array α} (w : l₁ = l₂) {P : α → Prop} {H : ∀ x ∈ l₁, P x} :
-    l₁.attachWith P H = l₂.attachWith P fun _ h => H _ (w ▸ h) := by
-  subst w
-  simp
-
-@[simp] theorem attach_push {a : α} {l : Array α} :
-    (l.push a).attach =
-      (l.attach.map (fun ⟨x, h⟩ => ⟨x, mem_push_of_mem a h⟩)).push ⟨a, by simp⟩ := by
-  cases l
-  rw [attach_congr (List.push_toArray _ _)]
-  simp [Function.comp_def]
-
-@[simp] theorem attachWith_push {a : α} {l : Array α} {P : α → Prop} {H : ∀ x ∈ l.push a, P x} :
-    (l.push a).attachWith P H =
-      (l.attachWith P (fun x h => by simp at H; exact H x (.inl h))).push ⟨a, H a (by simp)⟩ := by
-  cases l
-  simp [attachWith_congr (List.push_toArray _ _)]
-
-theorem pmap_eq_map_attach {p : α → Prop} (f : ∀ a, p a → β) (l H) :
-    pmap f l H = l.attach.map fun x => f x.1 (H _ x.2) := by
-  cases l
-  simp [List.pmap_eq_map_attach]
-
-theorem attach_map_coe (l : Array α) (f : α → β) :
-    (l.attach.map fun (i : {i // i ∈ l}) => f i) = l.map f := by
-  cases l
-  simp [List.attach_map_coe]
-
-theorem attach_map_val (l : Array α) (f : α → β) : (l.attach.map fun i => f i.val) = l.map f :=
-  attach_map_coe _ _
-
-@[simp]
-theorem attach_map_subtype_val (l : Array α) : l.attach.map Subtype.val = l := by
-  cases l; simp
-
-theorem attachWith_map_coe {p : α → Prop} (f : α → β) (l : Array α) (H : ∀ a ∈ l, p a) :
-    ((l.attachWith p H).map fun (i : { i // p i}) => f i) = l.map f := by
-  cases l; simp
-
-theorem attachWith_map_val {p : α → Prop} (f : α → β) (l : Array α) (H : ∀ a ∈ l, p a) :
-    ((l.attachWith p H).map fun i => f i.val) = l.map f :=
-  attachWith_map_coe _ _ _
-
-@[simp]
-theorem attachWith_map_subtype_val {p : α → Prop} (l : Array α) (H : ∀ a ∈ l, p a) :
-    (l.attachWith p H).map Subtype.val = l := by
-  cases l; simp
-
-@[simp]
-theorem mem_attach (l : Array α) : ∀ x, x ∈ l.attach
-  | ⟨a, h⟩ => by
-    have := mem_map.1 (by rw [attach_map_subtype_val] <;> exact h)
-    rcases this with ⟨⟨_, _⟩, m, rfl⟩
-    exact m
-
-@[simp]
-theorem mem_pmap {p : α → Prop} {f : ∀ a, p a → β} {l H b} :
-    b ∈ pmap f l H ↔ ∃ (a : _) (h : a ∈ l), f a (H a h) = b := by
-  simp only [pmap_eq_map_attach, mem_map, mem_attach, true_and, Subtype.exists, eq_comm]
-
-theorem mem_pmap_of_mem {p : α → Prop} {f : ∀ a, p a → β} {l H} {a} (h : a ∈ l) :
-    f a (H a h) ∈ pmap f l H := by
-  rw [mem_pmap]
-  exact ⟨a, h, rfl⟩
-
-@[simp]
-theorem size_pmap {p : α → Prop} {f : ∀ a, p a → β} {l H} : (pmap f l H).size = l.size := by
-  cases l; simp
-
-@[simp]
-theorem size_attach {L : Array α} : L.attach.size = L.size := by
-  cases L; simp
-
-@[simp]
-theorem size_attachWith {p : α → Prop} {l : Array α} {H} : (l.attachWith p H).size = l.size := by
-  cases l; simp
-
-@[simp]
-theorem pmap_eq_empty_iff {p : α → Prop} {f : ∀ a, p a → β} {l H} : pmap f l H = #[] ↔ l = #[] := by
-  cases l; simp
-
-theorem pmap_ne_empty_iff {P : α → Prop} (f : (a : α) → P a → β) {xs : Array α}
-    (H : ∀ (a : α), a ∈ xs → P a) : xs.pmap f H ≠ #[] ↔ xs ≠ #[] := by
-  cases xs; simp
-
-theorem pmap_eq_self {l : Array α} {p : α → Prop} (hp : ∀ (a : α), a ∈ l → p a)
-    (f : (a : α) → p a → α) : l.pmap f hp = l ↔ ∀ a (h : a ∈ l), f a (hp a h) = a := by
-  cases l; simp [List.pmap_eq_self]
-
-@[simp]
-theorem attach_eq_empty_iff {l : Array α} : l.attach = #[] ↔ l = #[] := by
-  cases l; simp
-
-theorem attach_ne_empty_iff {l : Array α} : l.attach ≠ #[] ↔ l ≠ #[] := by
-  cases l; simp
-
-@[simp]
-theorem attachWith_eq_empty_iff {l : Array α} {P : α → Prop} {H : ∀ a ∈ l, P a} :
-    l.attachWith P H = #[] ↔ l = #[] := by
-  cases l; simp
-
-theorem attachWith_ne_empty_iff {l : Array α} {P : α → Prop} {H : ∀ a ∈ l, P a} :
-    l.attachWith P H ≠ #[] ↔ l ≠ #[] := by
-  cases l; simp
-
-@[simp]
-theorem getElem?_pmap {p : α → Prop} (f : ∀ a, p a → β) {l : Array α} (h : ∀ a ∈ l, p a) (n : Nat) :
-    (pmap f l h)[n]? = Option.pmap f l[n]? fun x H => h x (mem_of_getElem? H) := by
-  cases l; simp
-
-@[simp]
-theorem getElem_pmap {p : α → Prop} (f : ∀ a, p a → β) {l : Array α} (h : ∀ a ∈ l, p a) {n : Nat}
-    (hn : n < (pmap f l h).size) :
-    (pmap f l h)[n] =
-      f (l[n]'(@size_pmap _ _ p f l h ▸ hn))
-        (h _ (getElem_mem (@size_pmap _ _ p f l h ▸ hn))) := by
-  cases l; simp
-
-@[simp]
-theorem getElem?_attachWith {xs : Array α} {i : Nat} {P : α → Prop} {H : ∀ a ∈ xs, P a} :
-    (xs.attachWith P H)[i]? = xs[i]?.pmap Subtype.mk (fun _ a => H _ (mem_of_getElem? a)) :=
-  getElem?_pmap ..
-
-@[simp]
-theorem getElem?_attach {xs : Array α} {i : Nat} :
-    xs.attach[i]? = xs[i]?.pmap Subtype.mk (fun _ a => mem_of_getElem? a) :=
-  getElem?_attachWith
-
-@[simp]
-theorem getElem_attachWith {xs : Array α} {P : α → Prop} {H : ∀ a ∈ xs, P a}
-    {i : Nat} (h : i < (xs.attachWith P H).size) :
-    (xs.attachWith P H)[i] = ⟨xs[i]'(by simpa using h), H _ (getElem_mem (by simpa using h))⟩ :=
-  getElem_pmap ..
-
-@[simp]
-theorem getElem_attach {xs : Array α} {i : Nat} (h : i < xs.attach.size) :
-    xs.attach[i] = ⟨xs[i]'(by simpa using h), getElem_mem (by simpa using h)⟩ :=
-  getElem_attachWith h
-
-theorem foldl_pmap (l : Array α) {P : α → Prop} (f : (a : α) → P a → β)
-  (H : ∀ (a : α), a ∈ l → P a) (g : γ → β → γ) (x : γ) :
-    (l.pmap f H).foldl g x = l.attach.foldl (fun acc a => g acc (f a.1 (H _ a.2))) x := by
-  rw [pmap_eq_map_attach, foldl_map]
-
-theorem foldr_pmap (l : Array α) {P : α → Prop} (f : (a : α) → P a → β)
-  (H : ∀ (a : α), a ∈ l → P a) (g : β → γ → γ) (x : γ) :
-    (l.pmap f H).foldr g x = l.attach.foldr (fun a acc => g (f a.1 (H _ a.2)) acc) x := by
-  rw [pmap_eq_map_attach, foldr_map]
-
-/--
-If we fold over `l.attach` with a function that ignores the membership predicate,
-we get the same results as folding over `l` directly.
-
-This is useful when we need to use `attach` to show termination.
-
-Unfortunately this can't be applied by `simp` because of the higher order unification problem,
-and even when rewriting we need to specify the function explicitly.
-See however `foldl_subtype` below.
--/
-theorem foldl_attach (l : Array α) (f : β → α → β) (b : β) :
-    l.attach.foldl (fun acc t => f acc t.1) b = l.foldl f b := by
-  rcases l with ⟨l⟩
-  simp only [List.attach_toArray, List.attachWith_mem_toArray, List.map_attach, size_toArray,
-    List.length_pmap, List.foldl_toArray', mem_toArray, List.foldl_subtype]
-  congr
-  ext
-  simpa using fun a => List.mem_of_getElem? a
-
-/--
-If we fold over `l.attach` with a function that ignores the membership predicate,
-we get the same results as folding over `l` directly.
-
-This is useful when we need to use `attach` to show termination.
-
-Unfortunately this can't be applied by `simp` because of the higher order unification problem,
-and even when rewriting we need to specify the function explicitly.
-See however `foldr_subtype` below.
--/
-theorem foldr_attach (l : Array α) (f : α → β → β) (b : β) :
-    l.attach.foldr (fun t acc => f t.1 acc) b = l.foldr f b := by
-  rcases l with ⟨l⟩
-  simp only [List.attach_toArray, List.attachWith_mem_toArray, List.map_attach, size_toArray,
-    List.length_pmap, List.foldr_toArray', mem_toArray, List.foldr_subtype]
-  congr
-  ext
-  simpa using fun a => List.mem_of_getElem? a
-
-theorem attach_map {l : Array α} (f : α → β) :
-    (l.map f).attach = l.attach.map (fun ⟨x, h⟩ => ⟨f x, mem_map_of_mem f h⟩) := by
-  cases l
-  ext <;> simp
-
-theorem attachWith_map {l : Array α} (f : α → β) {P : β → Prop} {H : ∀ (b : β), b ∈ l.map f → P b} :
-    (l.map f).attachWith P H = (l.attachWith (P ∘ f) (fun _ h => H _ (mem_map_of_mem f h))).map
-      fun ⟨x, h⟩ => ⟨f x, h⟩ := by
-  cases l
-  ext
-  · simp
-  · simp only [List.map_toArray, List.attachWith_toArray, List.getElem_toArray,
-      List.getElem_attachWith, List.getElem_map, Function.comp_apply]
-    erw [List.getElem_attachWith] -- Why is `erw` needed here?
-
-theorem map_attachWith {l : Array α} {P : α → Prop} {H : ∀ (a : α), a ∈ l → P a}
-    (f : { x // P x } → β) :
-    (l.attachWith P H).map f =
-      l.pmap (fun a (h : a ∈ l ∧ P a) => f ⟨a, H _ h.1⟩) (fun a h => ⟨h, H a h⟩) := by
-  cases l
-  ext <;> simp
-
-/-- See also `pmap_eq_map_attach` for writing `pmap` in terms of `map` and `attach`. -/
-theorem map_attach {l : Array α} (f : { x // x ∈ l } → β) :
-    l.attach.map f = l.pmap (fun a h => f ⟨a, h⟩) (fun _ => id) := by
-  cases l
-  ext <;> simp
-
-theorem attach_filterMap {l : Array α} {f : α → Option β} :
-    (l.filterMap f).attach = l.attach.filterMap
-      fun ⟨x, h⟩ => (f x).pbind (fun b m => some ⟨b, mem_filterMap.mpr ⟨x, h, m⟩⟩) := by
-  cases l
-  rw [attach_congr (List.filterMap_toArray f _)]
-  simp [List.attach_filterMap, List.map_filterMap, Function.comp_def]
-
-theorem attach_filter {l : Array α} (p : α → Bool) :
-    (l.filter p).attach = l.attach.filterMap
-      fun x => if w : p x.1 then some ⟨x.1, mem_filter.mpr ⟨x.2, w⟩⟩ else none := by
-  cases l
-  rw [attach_congr (List.filter_toArray p _)]
-  simp [List.attach_filter, List.map_filterMap, Function.comp_def]
-
--- We are still missing here `attachWith_filterMap` and `attachWith_filter`.
--- Also missing are `filterMap_attach`, `filter_attach`, `filterMap_attachWith` and `filter_attachWith`.
-
-theorem pmap_pmap {p : α → Prop} {q : β → Prop} (g : ∀ a, p a → β) (f : ∀ b, q b → γ) (l H₁ H₂) :
-    pmap f (pmap g l H₁) H₂ =
-      pmap (α := { x // x ∈ l }) (fun a h => f (g a h) (H₂ (g a h) (mem_pmap_of_mem a.2))) l.attach
-        (fun a _ => H₁ a a.2) := by
-  cases l
-  simp [List.pmap_pmap, List.pmap_map]
-
-@[simp] theorem pmap_append {p : ι → Prop} (f : ∀ a : ι, p a → α) (l₁ l₂ : Array ι)
-    (h : ∀ a ∈ l₁ ++ l₂, p a) :
-    (l₁ ++ l₂).pmap f h =
-      (l₁.pmap f fun a ha => h a (mem_append_left l₂ ha)) ++
-        l₂.pmap f fun a ha => h a (mem_append_right l₁ ha) := by
-  cases l₁
-  cases l₂
-  simp
-
-theorem pmap_append' {p : α → Prop} (f : ∀ a : α, p a → β) (l₁ l₂ : Array α)
-    (h₁ : ∀ a ∈ l₁, p a) (h₂ : ∀ a ∈ l₂, p a) :
-    ((l₁ ++ l₂).pmap f fun a ha => (mem_append.1 ha).elim (h₁ a) (h₂ a)) =
-      l₁.pmap f h₁ ++ l₂.pmap f h₂ :=
-  pmap_append f l₁ l₂ _
-
-@[simp] theorem attach_append (xs ys : Array α) :
-    (xs ++ ys).attach = xs.attach.map (fun ⟨x, h⟩ => ⟨x, mem_append_left ys h⟩) ++
-      ys.attach.map fun ⟨x, h⟩ => ⟨x, mem_append_right xs h⟩ := by
-  cases xs
-  cases ys
-  rw [attach_congr (List.append_toArray _ _)]
-  simp [List.attach_append, Function.comp_def]
-
-@[simp] theorem attachWith_append {P : α → Prop} {xs ys : Array α}
-    {H : ∀ (a : α), a ∈ xs ++ ys → P a} :
-    (xs ++ ys).attachWith P H = xs.attachWith P (fun a h => H a (mem_append_left ys h)) ++
-      ys.attachWith P (fun a h => H a (mem_append_right xs h)) := by
-  simp [attachWith, attach_append, map_pmap, pmap_append]
-
-@[simp] theorem pmap_reverse {P : α → Prop} (f : (a : α) → P a → β) (xs : Array α)
-    (H : ∀ (a : α), a ∈ xs.reverse → P a) :
-    xs.reverse.pmap f H = (xs.pmap f (fun a h => H a (by simpa using h))).reverse := by
-  induction xs <;> simp_all
-
-theorem reverse_pmap {P : α → Prop} (f : (a : α) → P a → β) (xs : Array α)
-    (H : ∀ (a : α), a ∈ xs → P a) :
-    (xs.pmap f H).reverse = xs.reverse.pmap f (fun a h => H a (by simpa using h)) := by
-  rw [pmap_reverse]
-
-@[simp] theorem attachWith_reverse {P : α → Prop} {xs : Array α}
-    {H : ∀ (a : α), a ∈ xs.reverse → P a} :
-    xs.reverse.attachWith P H =
-      (xs.attachWith P (fun a h => H a (by simpa using h))).reverse := by
-  cases xs
-  simp
-
-theorem reverse_attachWith {P : α → Prop} {xs : Array α}
-    {H : ∀ (a : α), a ∈ xs → P a} :
-    (xs.attachWith P H).reverse = (xs.reverse.attachWith P (fun a h => H a (by simpa using h))) := by
-  cases xs
-  simp
-
-@[simp] theorem attach_reverse (xs : Array α) :
-    xs.reverse.attach = xs.attach.reverse.map fun ⟨x, h⟩ => ⟨x, by simpa using h⟩ := by
-  cases xs
-  rw [attach_congr (List.reverse_toArray _)]
-  simp
-
-theorem reverse_attach (xs : Array α) :
-    xs.attach.reverse = xs.reverse.attach.map fun ⟨x, h⟩ => ⟨x, by simpa using h⟩ := by
-  cases xs
-  simp
-
-@[simp] theorem back?_pmap {P : α → Prop} (f : (a : α) → P a → β) (xs : Array α)
-    (H : ∀ (a : α), a ∈ xs → P a) :
-    (xs.pmap f H).back? = xs.attach.back?.map fun ⟨a, m⟩ => f a (H a m) := by
-  cases xs
-  simp
-
-@[simp] theorem back?_attachWith {P : α → Prop} {xs : Array α}
-    {H : ∀ (a : α), a ∈ xs → P a} :
-    (xs.attachWith P H).back? = xs.back?.pbind (fun a h => some ⟨a, H _ (mem_of_back?_eq_some h)⟩) := by
-  cases xs
-  simp
-
-@[simp]
-theorem back?_attach {xs : Array α} :
-    xs.attach.back? = xs.back?.pbind fun a h => some ⟨a, mem_of_back?_eq_some h⟩ := by
-  cases xs
-  simp
-
-/-! ## unattach
-
-`Array.unattach` is the (one-sided) inverse of `Array.attach`. It is a synonym for `Array.map Subtype.val`.
-
-We use it by providing a simp lemma `l.attach.unattach = l`, and simp lemmas which recognize higher order
-functions applied to `l : Array { x // p x }` which only depend on the value, not the predicate, and rewrite these
-in terms of a simpler function applied to `l.unattach`.
-
-Further, we provide simp lemmas that push `unattach` inwards.
--/
-
-/--
-A synonym for `l.map (·.val)`. Mostly this should not be needed by users.
-It is introduced as in intermediate step by lemmas such as `map_subtype`,
-and is ideally subsequently simplified away by `unattach_attach`.
-
-If not, usually the right approach is `simp [Array.unattach, -Array.map_subtype]` to unfold.
--/
-def unattach {α : Type _} {p : α → Prop} (l : Array { x // p x }) := l.map (·.val)
-
-@[simp] theorem unattach_nil {p : α → Prop} : (#[] : Array { x // p x }).unattach = #[] := rfl
-@[simp] theorem unattach_push {p : α → Prop} {a : { x // p x }} {l : Array { x // p x }} :
-    (l.push a).unattach = l.unattach.push a.1 := by
-  simp only [unattach, Array.map_push]
-
-@[simp] theorem size_unattach {p : α → Prop} {l : Array { x // p x }} :
-    l.unattach.size = l.size := by
-  unfold unattach
-  simp
-
-@[simp] theorem _root_.List.unattach_toArray {p : α → Prop} {l : List { x // p x }} :
-    l.toArray.unattach = l.unattach.toArray := by
-  simp only [unattach, List.map_toArray, List.unattach]
-
-@[simp] theorem toList_unattach {p : α → Prop} {l : Array { x // p x }} :
-    l.unattach.toList = l.toList.unattach := by
-  simp only [unattach, toList_map, List.unattach]
-
-@[simp] theorem unattach_attach {l : Array α} : l.attach.unattach = l := by
-  cases l
-  simp only [List.attach_toArray, List.unattach_toArray, List.unattach_attachWith]
-
-@[simp] theorem unattach_attachWith {p : α → Prop} {l : Array α}
-    {H : ∀ a ∈ l, p a} :
-    (l.attachWith p H).unattach = l := by
-  cases l
-  simp
-
-@[simp] theorem getElem?_unattach {p : α → Prop} {l : Array { x // p x }} (i : Nat) :
-    l.unattach[i]? = l[i]?.map Subtype.val := by
-  simp [unattach]
-
-@[simp] theorem getElem_unattach
-    {p : α → Prop} {l : Array { x // p x }} (i : Nat) (h : i < l.unattach.size) :
-    l.unattach[i] = (l[i]'(by simpa using h)).1 := by
-  simp [unattach]
-
-/-! ### Recognizing higher order functions using a function that only depends on the value. -/
-
-/--
-This lemma identifies folds over arrays of subtypes, where the function only depends on the value, not the proposition,
-and simplifies these to the function directly taking the value.
--/
-theorem foldl_subtype {p : α → Prop} {l : Array { x // p x }}
-    {f : β → { x // p x } → β} {g : β → α → β} {x : β}
-    {hf : ∀ b x h, f b ⟨x, h⟩ = g b x} :
-    l.foldl f x = l.unattach.foldl g x := by
-  cases l
-  simp only [List.foldl_toArray', List.unattach_toArray]
-  rw [List.foldl_subtype] -- Why can't simp do this?
-  simp [hf]
-
-/-- Variant of `foldl_subtype` with side condition to check `stop = l.size`. -/
-@[simp] theorem foldl_subtype' {p : α → Prop} {l : Array { x // p x }}
-    {f : β → { x // p x } → β} {g : β → α → β} {x : β}
-    {hf : ∀ b x h, f b ⟨x, h⟩ = g b x} (h : stop = l.size) :
-    l.foldl f x 0 stop = l.unattach.foldl g x := by
-  subst h
-  rwa [foldl_subtype]
-
-/--
-This lemma identifies folds over arrays of subtypes, where the function only depends on the value, not the proposition,
-and simplifies these to the function directly taking the value.
--/
-theorem foldr_subtype {p : α → Prop} {l : Array { x // p x }}
-    {f : { x // p x } → β → β} {g : α → β → β} {x : β}
-    {hf : ∀ x h b, f ⟨x, h⟩ b = g x b} :
-    l.foldr f x = l.unattach.foldr g x := by
-  cases l
-  simp only [List.foldr_toArray', List.unattach_toArray]
-  rw [List.foldr_subtype]
-  simp [hf]
-
-/-- Variant of `foldr_subtype` with side condition to check `stop = l.size`. -/
-@[simp] theorem foldr_subtype' {p : α → Prop} {l : Array { x // p x }}
-    {f : { x // p x } → β → β} {g : α → β → β} {x : β}
-    {hf : ∀ x h b, f ⟨x, h⟩ b = g x b} (h : start = l.size) :
-    l.foldr f x start 0 = l.unattach.foldr g x := by
-  subst h
-  rwa [foldr_subtype]
-
-/--
-This lemma identifies maps over arrays of subtypes, where the function only depends on the value, not the proposition,
-and simplifies these to the function directly taking the value.
--/
-@[simp] theorem map_subtype {p : α → Prop} {l : Array { x // p x }}
-    {f : { x // p x } → β} {g : α → β} {hf : ∀ x h, f ⟨x, h⟩ = g x} :
-    l.map f = l.unattach.map g := by
-  cases l
-  simp only [List.map_toArray, List.unattach_toArray]
-  rw [List.map_subtype]
-  simp [hf]
-
-@[simp] theorem filterMap_subtype {p : α → Prop} {l : Array { x // p x }}
-    {f : { x // p x } → Option β} {g : α → Option β} {hf : ∀ x h, f ⟨x, h⟩ = g x} :
-    l.filterMap f = l.unattach.filterMap g := by
-  cases l
-  simp only [size_toArray, List.filterMap_toArray', List.unattach_toArray, List.length_unattach,
-    mk.injEq]
-  rw [List.filterMap_subtype]
-  simp [hf]
-
-@[simp] theorem unattach_filter {p : α → Prop} {l : Array { x // p x }}
-    {f : { x // p x } → Bool} {g : α → Bool} {hf : ∀ x h, f ⟨x, h⟩ = g x} :
-    (l.filter f).unattach = l.unattach.filter g := by
-  cases l
-  simp [hf]
-
-/-! ### Simp lemmas pushing `unattach` inwards. -/
-
-@[simp] theorem unattach_reverse {p : α → Prop} {l : Array { x // p x }} :
-    l.reverse.unattach = l.unattach.reverse := by
-  cases l
-  simp
-
-@[simp] theorem unattach_append {p : α → Prop} {l₁ l₂ : Array { x // p x }} :
-    (l₁ ++ l₂).unattach = l₁.unattach ++ l₂.unattach := by
-  cases l₁
-  cases l₂
-  simp
-
 end Array

src/Init/Data/Array/BasicAux.lean

@@ -34,11 +34,11 @@ private theorem List.of_toArrayAux_eq_toArrayAux {as bs : List α} {cs ds : Arra
 
 @[simp] theorem List.toArray_eq_toArray_eq (as bs : List α) : (as.toArray = bs.toArray) = (as = bs) := by
   apply propext; apply Iff.intro
-  · intro h; simpa [toArray] using h
+  · intro h; simp [toArray] at h; have := of_toArrayAux_eq_toArrayAux h rfl; exact this.1
   · intro h; rw [h]
 
 def Array.mapM' [Monad m] (f : α → m β) (as : Array α) : m { bs : Array β // bs.size = as.size } :=
-  go 0 ⟨mkEmpty as.size, rfl⟩ (by simp)
+  go 0 ⟨mkEmpty as.size, rfl⟩ (by simp_arith)
 where
   go (i : Nat) (acc : { bs : Array β // bs.size = i }) (hle : i ≤ as.size) : m { bs : Array β // bs.size = as.size } := do
     if h : i = as.size then
@@ -60,7 +60,7 @@ where
       if ptrEq a b then
         go (i+1) as
       else
-        go (i+1) (as.set i b h)
+        go (i+1) (as.set ⟨i, h⟩ b)
     else
       return as
 

src/Init/Data/Array/BinSearch.lean

@@ -52,7 +52,7 @@ namespace Array
     let mid    := (lo + hi)/2
     let midVal := as.get! mid
     if lt midVal k then
-      if mid == lo then do let v ← add (); pure <| as.insertIdx! (lo+1) v
+      if mid == lo then do let v ← add (); pure <| as.insertAt! (lo+1) v
       else binInsertAux lt merge add as k mid hi
     else if lt k midVal then
       binInsertAux lt merge add as k lo mid
@@ -67,10 +67,10 @@ namespace Array
     (k : α) : m (Array α) :=
   let _ := Inhabited.mk k
   if as.isEmpty then do let v ← add (); pure <| as.push v
-  else if lt k (as.get! 0) then do let v ← add (); pure <| as.insertIdx! 0 v
+  else if lt k (as.get! 0) then do let v ← add (); pure <| as.insertAt! 0 v
   else if !lt (as.get! 0) k then as.modifyM 0 <| merge
-  else if lt as.back! k then do let v ← add (); pure <| as.push v
-  else if !lt k as.back! then as.modifyM (as.size - 1) <| merge
+  else if lt as.back k then do let v ← add (); pure <| as.push v
+  else if !lt k as.back then as.modifyM (as.size - 1) <| merge
   else binInsertAux lt merge add as k 0 (as.size - 1)
 
 @[inline] def binInsert {α : Type u} (lt : α → α → Bool) (as : Array α) (k : α) : Array α :=

src/Init/Data/Array/Bootstrap.lean

@@ -1,155 +0,0 @@
-/-
-Copyright (c) 2022 Mario Carneiro. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Mario Carneiro
--/
-
-prelude
-import Init.Data.List.TakeDrop
-
-/-!
-## Bootstrapping theorems about arrays
-
-This file contains some theorems about `Array` and `List` needed for `Init.Data.List.Impl`.
--/
-
-namespace Array
-
-theorem foldlM_toList.aux [Monad m]
-    (f : β → α → m β) (arr : Array α) (i j) (H : arr.size ≤ i + j) (b) :
-    foldlM.loop f arr arr.size (Nat.le_refl _) i j b = (arr.toList.drop j).foldlM f b := by
-  unfold foldlM.loop
-  split; split
-  · cases Nat.not_le_of_gt ‹_› (Nat.zero_add _ ▸ H)
-  · rename_i i; rw [Nat.succ_add] at H
-    simp [foldlM_toList.aux f arr i (j+1) H]
-    rw (occs := .pos [2]) [← List.getElem_cons_drop_succ_eq_drop ‹_›]
-    rfl
-  · rw [List.drop_of_length_le (Nat.ge_of_not_lt ‹_›)]; rfl
-
-@[simp] theorem foldlM_toList [Monad m]
-    (f : β → α → m β) (init : β) (arr : Array α) :
-    arr.toList.foldlM f init = arr.foldlM f init := by
-  simp [foldlM, foldlM_toList.aux]
-
-@[simp] theorem foldl_toList (f : β → α → β) (init : β) (arr : Array α) :
-    arr.toList.foldl f init = arr.foldl f init :=
-  List.foldl_eq_foldlM .. ▸ foldlM_toList ..
-
-theorem foldrM_eq_reverse_foldlM_toList.aux [Monad m]
-    (f : α → β → m β) (arr : Array α) (init : β) (i h) :
-    (arr.toList.take i).reverse.foldlM (fun x y => f y x) init = foldrM.fold f arr 0 i h init := by
-  unfold foldrM.fold
-  match i with
-  | 0 => simp [List.foldlM, List.take]
-  | i+1 => rw [← List.take_concat_get _ _ h]; simp [← (aux f arr · i)]
-
-theorem foldrM_eq_reverse_foldlM_toList [Monad m] (f : α → β → m β) (init : β) (arr : Array α) :
-    arr.foldrM f init = arr.toList.reverse.foldlM (fun x y => f y x) init := by
-  have : arr = #[] ∨ 0 < arr.size :=
-    match arr with | ⟨[]⟩ => .inl rfl | ⟨a::l⟩ => .inr (Nat.zero_lt_succ _)
-  match arr, this with | _, .inl rfl => rfl | arr, .inr h => ?_
-  simp [foldrM, h, ← foldrM_eq_reverse_foldlM_toList.aux, List.take_length]
-
-@[simp] theorem foldrM_toList [Monad m]
-    (f : α → β → m β) (init : β) (arr : Array α) :
-    arr.toList.foldrM f init = arr.foldrM f init := by
-  rw [foldrM_eq_reverse_foldlM_toList, List.foldlM_reverse]
-
-@[simp] theorem foldr_toList (f : α → β → β) (init : β) (arr : Array α) :
-    arr.toList.foldr f init = arr.foldr f init :=
-  List.foldr_eq_foldrM .. ▸ foldrM_toList ..
-
-@[simp] theorem push_toList (arr : Array α) (a : α) : (arr.push a).toList = arr.toList ++ [a] := by
-  simp [push, List.concat_eq_append]
-
-@[simp] theorem toListAppend_eq (arr : Array α) (l) : arr.toListAppend l = arr.toList ++ l := by
-  simp [toListAppend, ← foldr_toList]
-
-@[simp] theorem toListImpl_eq (arr : Array α) : arr.toListImpl = arr.toList := by
-  simp [toListImpl, ← foldr_toList]
-
-@[simp] theorem pop_toList (arr : Array α) : arr.pop.toList = arr.toList.dropLast := rfl
-
-@[simp] theorem append_eq_append (arr arr' : Array α) : arr.append arr' = arr ++ arr' := rfl
-
-@[simp] theorem toList_append (arr arr' : Array α) :
-    (arr ++ arr').toList = arr.toList ++ arr'.toList := by
-  rw [← append_eq_append]; unfold Array.append
-  rw [← foldl_toList]
-  induction arr'.toList generalizing arr <;> simp [*]
-
-@[simp] theorem toList_empty : (#[] : Array α).toList = [] := rfl
-
-@[simp] theorem append_nil (as : Array α) : as ++ #[] = as := by
-  apply ext'; simp only [toList_append, toList_empty, List.append_nil]
-
-@[simp] theorem nil_append (as : Array α) : #[] ++ as = as := by
-  apply ext'; simp only [toList_append, toList_empty, List.nil_append]
-
-@[simp] theorem append_assoc (as bs cs : Array α) : as ++ bs ++ cs = as ++ (bs ++ cs) := by
-  apply ext'; simp only [toList_append, List.append_assoc]
-
-@[simp] theorem appendList_eq_append
-    (arr : Array α) (l : List α) : arr.appendList l = arr ++ l := rfl
-
-@[simp] theorem appendList_toList (arr : Array α) (l : List α) :
-    (arr ++ l).toList = arr.toList ++ l := by
-  rw [← appendList_eq_append]; unfold Array.appendList
-  induction l generalizing arr <;> simp [*]
-
-@[deprecated "Use the reverse direction of `foldrM_toList`." (since := "2024-11-13")]
-theorem foldrM_eq_foldrM_toList [Monad m]
-    (f : α → β → m β) (init : β) (arr : Array α) :
-    arr.foldrM f init = arr.toList.foldrM f init := by
-  simp
-
-@[deprecated "Use the reverse direction of `foldlM_toList`." (since := "2024-11-13")]
-theorem foldlM_eq_foldlM_toList [Monad m]
-    (f : β → α → m β) (init : β) (arr : Array α) :
-    arr.foldlM f init = arr.toList.foldlM f init:= by
-  simp
-
-@[deprecated "Use the reverse direction of `foldr_toList`." (since := "2024-11-13")]
-theorem foldr_eq_foldr_toList
-    (f : α → β → β) (init : β) (arr : Array α) :
-    arr.foldr f init = arr.toList.foldr f init := by
-  simp
-
-@[deprecated "Use the reverse direction of `foldl_toList`." (since := "2024-11-13")]
-theorem foldl_eq_foldl_toList
-    (f : β → α → β) (init : β) (arr : Array α) :
-    arr.foldl f init = arr.toList.foldl f init:= by
-  simp
-
-@[deprecated foldlM_toList (since := "2024-09-09")]
-abbrev foldlM_eq_foldlM_data := @foldlM_toList
-
-@[deprecated foldl_toList (since := "2024-09-09")]
-abbrev foldl_eq_foldl_data := @foldl_toList
-
-@[deprecated foldrM_eq_reverse_foldlM_toList (since := "2024-09-09")]
-abbrev foldrM_eq_reverse_foldlM_data := @foldrM_eq_reverse_foldlM_toList
-
-@[deprecated foldrM_toList (since := "2024-09-09")]
-abbrev foldrM_eq_foldrM_data := @foldrM_toList
-
-@[deprecated foldr_toList (since := "2024-09-09")]
-abbrev foldr_eq_foldr_data := @foldr_toList
-
-@[deprecated push_toList (since := "2024-09-09")]
-abbrev push_data := @push_toList
-
-@[deprecated toListImpl_eq (since := "2024-09-09")]
-abbrev toList_eq := @toListImpl_eq
-
-@[deprecated pop_toList (since := "2024-09-09")]
-abbrev pop_data := @pop_toList
-
-@[deprecated toList_append (since := "2024-09-09")]
-abbrev append_data := @toList_append
-
-@[deprecated appendList_toList (since := "2024-09-09")]
-abbrev appendList_data := @appendList_toList
-
-end Array

src/Init/Data/Array/DecidableEq.lean

@@ -5,82 +5,43 @@ Authors: Leonardo de Moura
 -/
 prelude
 import Init.Data.Array.Basic
-import Init.Data.BEq
-import Init.Data.Nat.Lemmas
-import Init.Data.List.Nat.BEq
 import Init.ByCases
 
 namespace Array
 
-theorem rel_of_isEqvAux
-    {r : α → α → Bool} {a b : Array α} (hsz : a.size = b.size) {i : Nat} (hi : i ≤ a.size)
-    (heqv : Array.isEqvAux a b hsz r i hi)
-    {j : Nat} (hj : j < i) : r (a[j]'(Nat.lt_of_lt_of_le hj hi)) (b[j]'(Nat.lt_of_lt_of_le hj (hsz ▸ hi))) := by
-  induction i with
-  | zero => contradiction
-  | succ i ih =>
-    simp only [Array.isEqvAux, Bool.and_eq_true, decide_eq_true_eq] at heqv
-    by_cases hj' : j < i
-    next =>
-      exact ih _ heqv.right hj'
-    next =>
-      replace hj' : j = i := Nat.eq_of_le_of_lt_succ (Nat.not_lt.mp hj') hj
-      subst hj'
-      exact heqv.left
+theorem eq_of_isEqvAux [DecidableEq α] (a b : Array α) (hsz : a.size = b.size) (i : Nat) (hi : i ≤ a.size) (heqv : Array.isEqvAux a b hsz (fun x y => x = y) i) (j : Nat) (low : i ≤ j) (high : j < a.size) : a[j] = b[j]'(hsz ▸ high) := by
+  by_cases h : i < a.size
+  · unfold Array.isEqvAux at heqv
+    simp [h] at heqv
+    have hind := eq_of_isEqvAux a b hsz (i+1) (Nat.succ_le_of_lt h) heqv.2
+    by_cases heq : i = j
+    · subst heq; exact heqv.1
+    · exact hind j (Nat.succ_le_of_lt (Nat.lt_of_le_of_ne low heq)) high
+  · have heq : i = a.size := Nat.le_antisymm hi (Nat.ge_of_not_lt h)
+    subst heq
+    exact absurd (Nat.lt_of_lt_of_le high low) (Nat.lt_irrefl j)
+termination_by a.size - i
+decreasing_by decreasing_trivial_pre_omega
 
-theorem isEqvAux_of_rel {r : α → α → Bool} {a b : Array α} (hsz : a.size = b.size) {i : Nat} (hi : i ≤ a.size)
-    (w : ∀ j, (hj : j < i) → r (a[j]'(Nat.lt_of_lt_of_le hj hi)) (b[j]'(Nat.lt_of_lt_of_le hj (hsz ▸ hi)))) : Array.isEqvAux a b hsz r i hi := by
-  induction i with
-  | zero => simp [Array.isEqvAux]
-  | succ i ih =>
-    simp only [isEqvAux, Bool.and_eq_true]
-    exact ⟨w i (Nat.lt_add_one i), ih _ fun j hj => w j (Nat.lt_add_right 1 hj)⟩
 
-theorem rel_of_isEqv {r : α → α → Bool} {a b : Array α} :
-    Array.isEqv a b r → ∃ h : a.size = b.size, ∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h')) := by
-  simp only [isEqv]
-  split <;> rename_i h
-  · exact fun h' => ⟨h, fun i => rel_of_isEqvAux h (Nat.le_refl ..) h'⟩
-  · intro; contradiction
+theorem eq_of_isEqv [DecidableEq α] (a b : Array α) : Array.isEqv a b (fun x y => x = y) → a = b := by
+  simp [Array.isEqv]
+  split
+  next hsz =>
+   intro h
+   have aux := eq_of_isEqvAux a b hsz 0 (Nat.zero_le ..) h
+   exact ext a b hsz fun i h _ => aux i (Nat.zero_le ..) _
+  next => intro; contradiction
 
-theorem isEqv_iff_rel (a b : Array α) (r) :
-    Array.isEqv a b r ↔ ∃ h : a.size = b.size, ∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h')) :=
-  ⟨rel_of_isEqv, fun ⟨h, w⟩ => by
-    simp only [isEqv, ← h, ↓reduceDIte]
-    exact isEqvAux_of_rel h (by simp [h]) w⟩
+theorem isEqvAux_self [DecidableEq α] (a : Array α) (i : Nat) : Array.isEqvAux a a rfl (fun x y => x = y) i = true := by
+  unfold Array.isEqvAux
+  split
+  next h => simp [h, isEqvAux_self a (i+1)]
+  next h => simp [h]
+termination_by a.size - i
+decreasing_by decreasing_trivial_pre_omega
 
-theorem isEqv_eq_decide (a b : Array α) (r) :
-    Array.isEqv a b r =
-      if h : a.size = b.size then decide (∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h'))) else false := by
-  by_cases h : Array.isEqv a b r
-  · simp only [h, Bool.true_eq]
-    simp only [isEqv_iff_rel] at h
-    obtain ⟨h, w⟩ := h
-    simp [h, w]
-  · let h' := h
-    simp only [Bool.not_eq_true] at h
-    simp only [h, Bool.false_eq, dite_eq_right_iff, decide_eq_false_iff_not, Classical.not_forall,
-      Bool.not_eq_true]
-    simpa [isEqv_iff_rel] using h'
-
-@[simp] theorem isEqv_toList [BEq α] (a b : Array α) : (a.toList.isEqv b.toList r) = (a.isEqv b r) := by
-  simp [isEqv_eq_decide, List.isEqv_eq_decide]
-
-theorem eq_of_isEqv [DecidableEq α] (a b : Array α) (h : Array.isEqv a b (fun x y => x = y)) : a = b := by
-  have ⟨h, h'⟩ := rel_of_isEqv h
-  exact ext _ _ h (fun i lt _ => by simpa using h' i lt)
-
-theorem isEqvAux_self (r : α → α → Bool) (hr : ∀ a, r a a) (a : Array α) (i : Nat) (h : i ≤ a.size) :
-    Array.isEqvAux a a rfl r i h = true := by
-  induction i with
-  | zero => simp [Array.isEqvAux]
-  | succ i ih =>
-    simp_all only [isEqvAux, Bool.and_self]
-
-theorem isEqv_self_beq [BEq α] [ReflBEq α] (a : Array α) : Array.isEqv a a (· == ·) = true := by
-  simp [isEqv, isEqvAux_self]
-
-theorem isEqv_self [DecidableEq α] (a : Array α) : Array.isEqv a a (· = ·) = true := by
+theorem isEqv_self [DecidableEq α] (a : Array α) : Array.isEqv a a (fun x y => x = y) = true := by
   simp [isEqv, isEqvAux_self]
 
 instance [DecidableEq α] : DecidableEq (Array α) :=
@@ -89,22 +50,4 @@ instance [DecidableEq α] : DecidableEq (Array α) :=
     | true  => isTrue (eq_of_isEqv a b h)
     | false => isFalse fun h' => by subst h'; rw [isEqv_self] at h; contradiction
 
-theorem beq_eq_decide [BEq α] (a b : Array α) :
-    (a == b) = if h : a.size = b.size then
-      decide (∀ (i : Nat) (h' : i < a.size), a[i] == b[i]'(h ▸ h')) else false := by
-  simp [BEq.beq, isEqv_eq_decide]
-
-@[simp] theorem beq_toList [BEq α] (a b : Array α) : (a.toList == b.toList) = (a == b) := by
-  simp [beq_eq_decide, List.beq_eq_decide]
-
 end Array
-
-namespace List
-
-@[simp] theorem isEqv_toArray [BEq α] (a b : List α) : (a.toArray.isEqv b.toArray r) = (a.isEqv b r) := by
-  simp [isEqv_eq_decide, Array.isEqv_eq_decide]
-
-@[simp] theorem beq_toArray [BEq α] (a b : List α) : (a.toArray == b.toArray) = (a == b) := by
-  simp [beq_eq_decide, Array.beq_eq_decide]
-
-end List

src/Init/Data/Array/Find.lean

@@ -1,281 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Kim Morrison
--/
-prelude
-import Init.Data.List.Find
-import Init.Data.Array.Lemmas
-import Init.Data.Array.Attach
-
-/-!
-# Lemmas about `Array.findSome?`, `Array.find?`.
--/
-
-namespace Array
-
-open Nat
-
-/-! ### findSome? -/
-
-@[simp] theorem findSomeRev?_push_of_isSome (l : Array α) (h : (f a).isSome) : (l.push a).findSomeRev? f = f a := by
-  cases l; simp_all
-
-@[simp] theorem findSomeRev?_push_of_isNone (l : Array α) (h : (f a).isNone) : (l.push a).findSomeRev? f = l.findSomeRev? f := by
-  cases l; simp_all
-
-theorem exists_of_findSome?_eq_some {f : α → Option β} {l : Array α} (w : l.findSome? f = some b) :
-    ∃ a, a ∈ l ∧ f a = b := by
-  cases l; simp_all [List.exists_of_findSome?_eq_some]
-
-@[simp] theorem findSome?_eq_none_iff : findSome? p l = none ↔ ∀ x ∈ l, p x = none := by
-  cases l; simp
-
-@[simp] theorem findSome?_isSome_iff {f : α → Option β} {l : Array α} :
-    (l.findSome? f).isSome ↔ ∃ x, x ∈ l ∧ (f x).isSome := by
-  cases l; simp
-
-theorem findSome?_eq_some_iff {f : α → Option β} {l : Array α} {b : β} :
-    l.findSome? f = some b ↔ ∃ (l₁ : Array α) (a : α) (l₂ : Array α), l = l₁.push a ++ l₂ ∧ f a = some b ∧ ∀ x ∈ l₁, f x = none := by
-  cases l
-  simp only [List.findSome?_toArray, List.findSome?_eq_some_iff]
-  constructor
-  · rintro ⟨l₁, a, l₂, rfl, h₁, h₂⟩
-    exact ⟨l₁.toArray, a, l₂.toArray, by simp_all⟩
-  · rintro ⟨l₁, a, l₂, h₀, h₁, h₂⟩
-    exact ⟨l₁.toList, a, l₂.toList, by simpa using congrArg toList h₀, h₁, by simpa⟩
-
-@[simp] theorem findSome?_guard (l : Array α) : findSome? (Option.guard fun x => p x) l = find? p l := by
-  cases l; simp
-
-@[simp] theorem getElem?_zero_filterMap (f : α → Option β) (l : Array α) : (l.filterMap f)[0]? = l.findSome? f := by
-  cases l; simp [← List.head?_eq_getElem?]
-
-@[simp] theorem getElem_zero_filterMap (f : α → Option β) (l : Array α) (h) :
-    (l.filterMap f)[0] = (l.findSome? f).get (by cases l; simpa [List.length_filterMap_eq_countP] using h) := by
-  cases l; simp [← List.head_eq_getElem, ← getElem?_zero_filterMap]
-
-@[simp] theorem back?_filterMap (f : α → Option β) (l : Array α) : (l.filterMap f).back? = l.findSomeRev? f := by
-  cases l; simp
-
-@[simp] theorem back!_filterMap [Inhabited β] (f : α → Option β) (l : Array α) :
-    (l.filterMap f).back! = (l.findSomeRev? f).getD default := by
-  cases l; simp
-
-@[simp] theorem map_findSome? (f : α → Option β) (g : β → γ) (l : Array α) :
-    (l.findSome? f).map g = l.findSome? (Option.map g ∘ f) := by
-  cases l; simp
-
-theorem findSome?_map (f : β → γ) (l : Array β) : findSome? p (l.map f) = l.findSome? (p ∘ f) := by
-  cases l; simp [List.findSome?_map]
-
-theorem findSome?_append {l₁ l₂ : Array α} : (l₁ ++ l₂).findSome? f = (l₁.findSome? f).or (l₂.findSome? f) := by
-  cases l₁; cases l₂; simp [List.findSome?_append]
-
-theorem getElem?_zero_flatten (L : Array (Array α)) :
-    (flatten L)[0]? = L.findSome? fun l => l[0]? := by
-  cases L using array_array_induction
-  simp [← List.head?_eq_getElem?, List.head?_flatten, List.findSome?_map, Function.comp_def]
-
-theorem getElem_zero_flatten.proof {L : Array (Array α)} (h : 0 < L.flatten.size) :
-    (L.findSome? fun l => l[0]?).isSome := by
-  cases L using array_array_induction
-  simp only [List.findSome?_toArray, List.findSome?_map, Function.comp_def, List.getElem?_toArray,
-    List.findSome?_isSome_iff, List.isSome_getElem?]
-  simp only [flatten_toArray_map_toArray, size_toArray, List.length_flatten,
-    Nat.sum_pos_iff_exists_pos, List.mem_map] at h
-  obtain ⟨_, ⟨xs, m, rfl⟩, h⟩ := h
-  exact ⟨xs, m, by simpa using h⟩
-
-theorem getElem_zero_flatten {L : Array (Array α)} (h) :
-    (flatten L)[0] = (L.findSome? fun l => l[0]?).get (getElem_zero_flatten.proof h) := by
-  have t := getElem?_zero_flatten L
-  simp [getElem?_eq_getElem, h] at t
-  simp [← t]
-
-theorem back?_flatten {L : Array (Array α)} :
-    (flatten L).back? = (L.findSomeRev? fun l => l.back?) := by
-  cases L using array_array_induction
-  simp [List.getLast?_flatten, ← List.map_reverse, List.findSome?_map, Function.comp_def]
-
-theorem findSome?_mkArray : findSome? f (mkArray n a) = if n = 0 then none else f a := by
-  simp [mkArray_eq_toArray_replicate, List.findSome?_replicate]
-
-@[simp] theorem findSome?_mkArray_of_pos (h : 0 < n) : findSome? f (mkArray n a) = f a := by
-  simp [findSome?_mkArray, Nat.ne_of_gt h]
-
--- Argument is unused, but used to decide whether `simp` should unfold.
-@[simp] theorem findSome?_mkArray_of_isSome (_ : (f a).isSome) :
-   findSome? f (mkArray n a) = if n = 0 then none else f a := by
-  simp [findSome?_mkArray]
-
-@[simp] theorem findSome?_mkArray_of_isNone (h : (f a).isNone) :
-    findSome? f (mkArray n a) = none := by
-  rw [Option.isNone_iff_eq_none] at h
-  simp [findSome?_mkArray, h]
-
-/-! ### find? -/
-
-@[simp] theorem find?_singleton (a : α) (p : α → Bool) :
-    #[a].find? p = if p a then some a else none := by
-  simp [singleton_eq_toArray_singleton]
-
-@[simp] theorem findRev?_push_of_pos (l : Array α) (h : p a) :
-    findRev? p (l.push a) = some a := by
-  cases l; simp [h]
-
-@[simp] theorem findRev?_cons_of_neg (l : Array α) (h : ¬p a) :
-    findRev? p (l.push a) = findRev? p l := by
-  cases l; simp [h]
-
-@[simp] theorem find?_eq_none : find? p l = none ↔ ∀ x ∈ l, ¬ p x := by
-  cases l; simp
-
-theorem find?_eq_some_iff_append {xs : Array α} :
-    xs.find? p = some b ↔ p b ∧ ∃ (as bs : Array α), xs = as.push b ++ bs ∧ ∀ a ∈ as, !p a := by
-  rcases xs with ⟨xs⟩
-  simp only [List.find?_toArray, List.find?_eq_some_iff_append, Bool.not_eq_eq_eq_not,
-    Bool.not_true, exists_and_right, and_congr_right_iff]
-  intro w
-  constructor
-  · rintro ⟨as, ⟨⟨x, rfl⟩, h⟩⟩
-    exact ⟨as.toArray, ⟨x.toArray, by simp⟩ , by simpa using h⟩
-  · rintro ⟨as, ⟨⟨x, h'⟩, h⟩⟩
-    exact ⟨as.toList, ⟨x.toList, by simpa using congrArg Array.toList h'⟩,
-      by simpa using h⟩
-
-@[simp]
-theorem find?_push_eq_some {xs : Array α} :
-    (xs.push a).find? p = some b ↔ xs.find? p = some b ∨ (xs.find? p = none ∧ (p a ∧ a = b)) := by
-  cases xs; simp
-
-@[simp] theorem find?_isSome {xs : Array α} {p : α → Bool} : (xs.find? p).isSome ↔ ∃ x, x ∈ xs ∧ p x := by
-  cases xs; simp
-
-theorem find?_some {xs : Array α} (h : find? p xs = some a) : p a := by
-  cases xs
-  simp at h
-  exact List.find?_some h
-
-theorem mem_of_find?_eq_some {xs : Array α} (h : find? p xs = some a) : a ∈ xs := by
-  cases xs
-  simp at h
-  simpa using List.mem_of_find?_eq_some h
-
-theorem get_find?_mem {xs : Array α} (h) : (xs.find? p).get h ∈ xs := by
-  cases xs
-  simp [List.get_find?_mem]
-
-@[simp] theorem find?_filter {xs : Array α} (p q : α → Bool) :
-    (xs.filter p).find? q = xs.find? (fun a => p a ∧ q a) := by
-  cases xs; simp
-
-@[simp] theorem getElem?_zero_filter (p : α → Bool) (l : Array α) :
-    (l.filter p)[0]? = l.find? p := by
-  cases l; simp [← List.head?_eq_getElem?]
-
-@[simp] theorem getElem_zero_filter (p : α → Bool) (l : Array α) (h) :
-    (l.filter p)[0] =
-      (l.find? p).get (by cases l; simpa [← List.countP_eq_length_filter] using h) := by
-  cases l
-  simp [List.getElem_zero_eq_head]
-
-@[simp] theorem back?_filter (p : α → Bool) (l : Array α) : (l.filter p).back? = l.findRev? p := by
-  cases l; simp
-
-@[simp] theorem back!_filter [Inhabited α] (p : α → Bool) (l : Array α) :
-    (l.filter p).back! = (l.findRev? p).get! := by
-  cases l; simp [Option.get!_eq_getD]
-
-@[simp] theorem find?_filterMap (xs : Array α) (f : α → Option β) (p : β → Bool) :
-    (xs.filterMap f).find? p = (xs.find? (fun a => (f a).any p)).bind f := by
-  cases xs; simp
-
-@[simp] theorem find?_map (f : β → α) (xs : Array β) :
-    find? p (xs.map f) = (xs.find? (p ∘ f)).map f := by
-  cases xs; simp
-
-@[simp] theorem find?_append {l₁ l₂ : Array α} :
-    (l₁ ++ l₂).find? p = (l₁.find? p).or (l₂.find? p) := by
-  cases l₁
-  cases l₂
-  simp
-
-@[simp] theorem find?_flatten (xs : Array (Array α)) (p : α → Bool) :
-    xs.flatten.find? p = xs.findSome? (·.find? p) := by
-  cases xs using array_array_induction
-  simp [List.findSome?_map, Function.comp_def]
-
-theorem find?_flatten_eq_none {xs : Array (Array α)} {p : α → Bool} :
-    xs.flatten.find? p = none ↔ ∀ ys ∈ xs, ∀ x ∈ ys, !p x := by
-  simp
-
-/--
-If `find? p` returns `some a` from `xs.flatten`, then `p a` holds, and
-some array in `xs` contains `a`, and no earlier element of that array satisfies `p`.
-Moreover, no earlier array in `xs` has an element satisfying `p`.
--/
-theorem find?_flatten_eq_some {xs : Array (Array α)} {p : α → Bool} {a : α} :
-    xs.flatten.find? p = some a ↔
-      p a ∧ ∃ (as : Array (Array α)) (ys zs : Array α) (bs : Array (Array α)),
-        xs = as.push (ys.push a ++ zs) ++ bs ∧
-        (∀ a ∈ as, ∀ x ∈ a, !p x) ∧ (∀ x ∈ ys, !p x) := by
-  cases xs using array_array_induction
-  simp only [flatten_toArray_map_toArray, List.find?_toArray, List.find?_flatten_eq_some]
-  simp only [Bool.not_eq_eq_eq_not, Bool.not_true, exists_and_right, and_congr_right_iff]
-  intro w
-  constructor
-  · rintro ⟨as, ys, ⟨⟨zs, bs, rfl⟩, h₁, h₂⟩⟩
-    exact ⟨as.toArray.map List.toArray, ys.toArray,
-      ⟨zs.toArray, bs.toArray.map List.toArray, by simp⟩, by simpa using h₁, by simpa using h₂⟩
-  · rintro ⟨as, ys, ⟨⟨zs, bs, h⟩, h₁, h₂⟩⟩
-    replace h := congrArg (·.map Array.toList) (congrArg Array.toList h)
-    simp [Function.comp_def] at h
-    exact ⟨as.toList.map Array.toList, ys.toList,
-      ⟨zs.toList, bs.toList.map Array.toList, by simpa using h⟩,
-        by simpa using h₁, by simpa using h₂⟩
-
-@[simp] theorem find?_flatMap (xs : Array α) (f : α → Array β) (p : β → Bool) :
-    (xs.flatMap f).find? p = xs.findSome? (fun x => (f x).find? p) := by
-  cases xs
-  simp [List.find?_flatMap, Array.flatMap_toArray]
-
-theorem find?_flatMap_eq_none {xs : Array α} {f : α → Array β} {p : β → Bool} :
-    (xs.flatMap f).find? p = none ↔ ∀ x ∈ xs, ∀ y ∈ f x, !p y := by
-  simp
-
-theorem find?_mkArray :
-    find? p (mkArray n a) = if n = 0 then none else if p a then some a else none := by
-  simp [mkArray_eq_toArray_replicate, List.find?_replicate]
-
-@[simp] theorem find?_mkArray_of_length_pos (h : 0 < n) :
-    find? p (mkArray n a) = if p a then some a else none := by
-  simp [find?_mkArray, Nat.ne_of_gt h]
-
-@[simp] theorem find?_mkArray_of_pos (h : p a) :
-    find? p (mkArray n a) = if n = 0 then none else some a := by
-  simp [find?_mkArray, h]
-
-@[simp] theorem find?_mkArray_of_neg (h : ¬ p a) : find? p (mkArray n a) = none := by
-  simp [find?_mkArray, h]
-
--- This isn't a `@[simp]` lemma since there is already a lemma for `l.find? p = none` for any `l`.
-theorem find?_mkArray_eq_none {n : Nat} {a : α} {p : α → Bool} :
-    (mkArray n a).find? p = none ↔ n = 0 ∨ !p a := by
-  simp [mkArray_eq_toArray_replicate, List.find?_replicate_eq_none, Classical.or_iff_not_imp_left]
-
-@[simp] theorem find?_mkArray_eq_some {n : Nat} {a b : α} {p : α → Bool} :
-    (mkArray n a).find? p = some b ↔ n ≠ 0 ∧ p a ∧ a = b := by
-  simp [mkArray_eq_toArray_replicate]
-
-@[simp] theorem get_find?_mkArray (n : Nat) (a : α) (p : α → Bool) (h) :
-    ((mkArray n a).find? p).get h = a := by
-  simp [mkArray_eq_toArray_replicate]
-
-theorem find?_pmap {P : α → Prop} (f : (a : α) → P a → β) (xs : Array α)
-    (H : ∀ (a : α), a ∈ xs → P a) (p : β → Bool) :
-    (xs.pmap f H).find? p = (xs.attach.find? (fun ⟨a, m⟩ => p (f a (H a m)))).map fun ⟨a, m⟩ => f a (H a m) := by
-  simp only [pmap_eq_map_attach, find?_map]
-  rfl
-
-end Array

src/Init/Data/Array/GetLit.lean

@@ -1,46 +0,0 @@
-/-
-Copyright (c) 2018 Microsoft Corporation. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Leonardo de Moura
--/
-
-prelude
-import Init.Data.Array.Basic
-
-namespace Array
-
-/-! ### getLit -/
-
--- auxiliary declaration used in the equation compiler when pattern matching array literals.
-abbrev getLit {α : Type u} {n : Nat} (a : Array α) (i : Nat) (h₁ : a.size = n) (h₂ : i < n) : α :=
-  have := h₁.symm ▸ h₂
-  a[i]
-
-theorem extLit {n : Nat}
-    (a b : Array α)
-    (hsz₁ : a.size = n) (hsz₂ : b.size = n)
-    (h : (i : Nat) → (hi : i < n) → a.getLit i hsz₁ hi = b.getLit i hsz₂ hi) : a = b :=
-  Array.ext a b (hsz₁.trans hsz₂.symm) fun i hi₁ _ => h i (hsz₁ ▸ hi₁)
-
-def toListLitAux (a : Array α) (n : Nat) (hsz : a.size = n) : ∀ (i : Nat), i ≤ a.size → List α → List α
-  | 0,     _,  acc => acc
-  | (i+1), hi, acc => toListLitAux a n hsz i (Nat.le_of_succ_le hi) (a.getLit i hsz (Nat.lt_of_lt_of_eq (Nat.lt_of_lt_of_le (Nat.lt_succ_self i) hi) hsz) :: acc)
-
-def toArrayLit (a : Array α) (n : Nat) (hsz : a.size = n) : Array α :=
-  List.toArray <| toListLitAux a n hsz n (hsz ▸ Nat.le_refl _) []
-
-theorem toArrayLit_eq (as : Array α) (n : Nat) (hsz : as.size = n) : as = toArrayLit as n hsz := by
-  apply ext'
-  simp [toArrayLit, toList_toArray]
-  have hle : n ≤ as.size := hsz ▸ Nat.le_refl _
-  have hge : as.size ≤ n := hsz ▸ Nat.le_refl _
-  have := go n hle
-  rw [List.drop_eq_nil_of_le hge] at this
-  rw [this]
-where
-  getLit_eq (as : Array α) (i : Nat) (h₁ : as.size = n) (h₂ : i < n) : as.getLit i h₁ h₂ = getElem as.toList i ((id (α := as.toList.length = n) h₁) ▸ h₂) :=
-    rfl
-  go (i : Nat) (hi : i ≤ as.size) : toListLitAux as n hsz i hi (as.toList.drop i) = as.toList := by
-    induction i <;> simp only [List.drop, toListLitAux, getLit_eq, List.getElem_cons_drop_succ_eq_drop, *]
-
-end Array

src/Init/Data/Array/MapIdx.lean

@@ -1,112 +0,0 @@
-/-
-Copyright (c) 2022 Mario Carneiro. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Mario Carneiro, Kim Morrison
--/
-prelude
-import Init.Data.Array.Lemmas
-import Init.Data.List.MapIdx
-
-namespace Array
-
-/-! ### mapFinIdx -/
-
--- This could also be proved from `SatisfiesM_mapIdxM` in Batteries.
-theorem mapFinIdx_induction (as : Array α) (f : Fin as.size → α → β)
-    (motive : Nat → Prop) (h0 : motive 0)
-    (p : Fin as.size → β → Prop)
-    (hs : ∀ i, motive i.1 → p i (f i as[i]) ∧ motive (i + 1)) :
-    motive as.size ∧ ∃ eq : (Array.mapFinIdx as f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((Array.mapFinIdx as f)[i]) := by
-  let rec go {bs i j h} (h₁ : j = bs.size) (h₂ : ∀ i h h', p ⟨i, h⟩ bs[i]) (hm : motive j) :
-    let arr : Array β := Array.mapFinIdxM.map (m := Id) as f i j h bs
-    motive as.size ∧ ∃ eq : arr.size = as.size, ∀ i h, p ⟨i, h⟩ arr[i] := by
-    induction i generalizing j bs with simp [mapFinIdxM.map]
-    | zero =>
-      have := (Nat.zero_add _).symm.trans h
-      exact ⟨this ▸ hm, h₁ ▸ this, fun _ _ => h₂ ..⟩
-    | succ i ih =>
-      apply @ih (bs.push (f ⟨j, by omega⟩ as[j])) (j + 1) (by omega) (by simp; omega)
-      · intro i i_lt h'
-        rw [getElem_push]
-        split
-        · apply h₂
-        · simp only [size_push] at h'
-          obtain rfl : i = j := by omega
-          apply (hs ⟨i, by omega⟩ hm).1
-      · exact (hs ⟨j, by omega⟩ hm).2
-  simp [mapFinIdx, mapFinIdxM]; exact go rfl nofun h0
-
-theorem mapFinIdx_spec (as : Array α) (f : Fin as.size → α → β)
-    (p : Fin as.size → β → Prop) (hs : ∀ i, p i (f i as[i])) :
-    ∃ eq : (Array.mapFinIdx as f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((Array.mapFinIdx as f)[i]) :=
-  (mapFinIdx_induction _ _ (fun _ => True) trivial p fun _ _ => ⟨hs .., trivial⟩).2
-
-@[simp] theorem size_mapFinIdx (a : Array α) (f : Fin a.size → α → β) : (a.mapFinIdx f).size = a.size :=
-  (mapFinIdx_spec (p := fun _ _ => True) (hs := fun _ => trivial)).1
-
-@[simp] theorem size_zipWithIndex (as : Array α) : as.zipWithIndex.size = as.size :=
-  Array.size_mapFinIdx _ _
-
-@[simp] theorem getElem_mapFinIdx (a : Array α) (f : Fin a.size → α → β) (i : Nat)
-    (h : i < (mapFinIdx a f).size) :
-    (a.mapFinIdx f)[i] = f ⟨i, by simp_all⟩ (a[i]'(by simp_all)) :=
-  (mapFinIdx_spec _ _ (fun i b => b = f i a[i]) fun _ => rfl).2 i _
-
-@[simp] theorem getElem?_mapFinIdx (a : Array α) (f : Fin a.size → α → β) (i : Nat) :
-    (a.mapFinIdx f)[i]? =
-      a[i]?.pbind fun b h => f ⟨i, (getElem?_eq_some_iff.1 h).1⟩ b := by
-  simp only [getElem?_def, size_mapFinIdx, getElem_mapFinIdx]
-  split <;> simp_all
-
-@[simp] theorem toList_mapFinIdx (a : Array α) (f : Fin a.size → α → β) :
-    (a.mapFinIdx f).toList = a.toList.mapFinIdx (fun i a => f ⟨i, by simp⟩ a) := by
-  apply List.ext_getElem <;> simp
-
-/-! ### mapIdx -/
-
-theorem mapIdx_induction (f : Nat → α → β) (as : Array α)
-    (motive : Nat → Prop) (h0 : motive 0)
-    (p : Fin as.size → β → Prop)
-    (hs : ∀ i, motive i.1 → p i (f i as[i]) ∧ motive (i + 1)) :
-    motive as.size ∧ ∃ eq : (as.mapIdx f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((as.mapIdx f)[i]) :=
-  mapFinIdx_induction as (fun i a => f i a) motive h0 p hs
-
-theorem mapIdx_spec (f : Nat → α → β) (as : Array α)
-    (p : Fin as.size → β → Prop) (hs : ∀ i, p i (f i as[i])) :
-    ∃ eq : (as.mapIdx f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((as.mapIdx f)[i]) :=
-  (mapIdx_induction _ _ (fun _ => True) trivial p fun _ _ => ⟨hs .., trivial⟩).2
-
-@[simp] theorem size_mapIdx (f : Nat → α → β) (as : Array α) : (as.mapIdx f).size = as.size :=
-  (mapIdx_spec (p := fun _ _ => True) (hs := fun _ => trivial)).1
-
-@[simp] theorem getElem_mapIdx (f : Nat → α → β) (as : Array α) (i : Nat)
-    (h : i < (as.mapIdx f).size) :
-    (as.mapIdx f)[i] = f i (as[i]'(by simp_all)) :=
-  (mapIdx_spec _ _ (fun i b => b = f i as[i]) fun _ => rfl).2 i (by simp_all)
-
-@[simp] theorem getElem?_mapIdx (f : Nat → α → β) (as : Array α) (i : Nat) :
-    (as.mapIdx f)[i]? =
-      as[i]?.map (f i) := by
-  simp [getElem?_def, size_mapIdx, getElem_mapIdx]
-
-@[simp] theorem toList_mapIdx (f : Nat → α → β) (as : Array α) :
-    (as.mapIdx f).toList = as.toList.mapIdx (fun i a => f i a) := by
-  apply List.ext_getElem <;> simp
-
-end Array
-
-namespace List
-
-@[simp] theorem mapFinIdx_toArray (l : List α) (f : Fin l.length → α → β) :
-    l.toArray.mapFinIdx f = (l.mapFinIdx f).toArray := by
-  ext <;> simp
-
-@[simp] theorem mapIdx_toArray (f : Nat → α → β) (l : List α) :
-    l.toArray.mapIdx f = (l.mapIdx f).toArray := by
-  ext <;> simp
-
-end List

src/Init/Data/Array/Mem.lean

@@ -10,16 +10,25 @@ import Init.Data.List.BasicAux
 
 namespace Array
 
+/-- `a ∈ as` is a predicate which asserts that `a` is in the array `as`. -/
+-- NB: This is defined as a structure rather than a plain def so that a lemma
+-- like `sizeOf_lt_of_mem` will not apply with no actual arrays around.
+structure Mem (a : α) (as : Array α) : Prop where
+  val : a ∈ as.data
+
+instance : Membership α (Array α) where
+  mem a as := Mem a as
+
 theorem sizeOf_lt_of_mem [SizeOf α] {as : Array α} (h : a ∈ as) : sizeOf a < sizeOf as := by
   cases as with | _ as =>
   exact Nat.lt_trans (List.sizeOf_lt_of_mem h.val) (by simp_arith)
 
-theorem sizeOf_get [SizeOf α] (as : Array α) (i : Nat) (h : i < as.size) : sizeOf (as.get i h) < sizeOf as := by
+theorem sizeOf_get [SizeOf α] (as : Array α) (i : Fin as.size) : sizeOf (as.get i) < sizeOf as := by
   cases as with | _ as =>
-  simpa using Nat.lt_trans (List.sizeOf_get _ ⟨i, h⟩) (by simp_arith)
+  exact Nat.lt_trans (List.sizeOf_get ..) (by simp_arith)
 
 @[simp] theorem sizeOf_getElem [SizeOf α] (as : Array α) (i : Nat) (h : i < as.size) :
-  sizeOf (as[i]'h) < sizeOf as := sizeOf_get _ _ h
+  sizeOf (as[i]'h) < sizeOf as := sizeOf_get _ _
 
 /-- This tactic, added to the `decreasing_trivial` toolbox, proves that
 `sizeOf arr[i] < sizeOf arr`, which is useful for well founded recursions
@@ -29,8 +38,8 @@ macro "array_get_dec" : tactic =>
     -- subsumed by simp
     -- | with_reducible apply sizeOf_get
     -- | with_reducible apply sizeOf_getElem
-    | (with_reducible apply Nat.lt_of_lt_of_le (sizeOf_get ..)); simp_arith
-    | (with_reducible apply Nat.lt_of_lt_of_le (sizeOf_getElem ..)); simp_arith
+    | (with_reducible apply Nat.lt_trans (sizeOf_get ..)); simp_arith
+    | (with_reducible apply Nat.lt_trans (sizeOf_getElem ..)); simp_arith
     )
 
 macro_rules | `(tactic| decreasing_trivial) => `(tactic| array_get_dec)
@@ -43,7 +52,7 @@ macro "array_mem_dec" : tactic =>
   `(tactic| first
     | with_reducible apply Array.sizeOf_lt_of_mem; assumption; done
     | with_reducible
-        apply Nat.lt_of_lt_of_le (Array.sizeOf_lt_of_mem ?h)
+        apply Nat.lt_trans (Array.sizeOf_lt_of_mem ?h)
         case' h => assumption
       simp_arith)
 

src/Init/Data/Array/Monadic.lean

@@ -1,159 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Kim Morrison
--/
-prelude
-import Init.Data.Array.Lemmas
-import Init.Data.Array.Attach
-import Init.Data.List.Monadic
-
-/-!
-# Lemmas about `Array.forIn'` and `Array.forIn`.
--/
-
-namespace Array
-
-open Nat
-
-/-! ## Monadic operations -/
-
-/-! ### mapM -/
-
-theorem mapM_eq_foldlM_push [Monad m] [LawfulMonad m] (f : α → m β) (l : Array α) :
-    mapM f l = l.foldlM (fun acc a => return (acc.push (← f a))) #[] := by
-  rcases l with ⟨l⟩
-  simp only [List.mapM_toArray, bind_pure_comp, size_toArray, List.foldlM_toArray']
-  rw [List.mapM_eq_reverse_foldlM_cons]
-  simp only [bind_pure_comp, Functor.map_map]
-  suffices ∀ (k), (fun a => a.reverse.toArray) <$> List.foldlM (fun acc a => (fun a => a :: acc) <$> f a) k l =
-      List.foldlM (fun acc a => acc.push <$> f a) k.reverse.toArray l by
-    exact this []
-  intro k
-  induction l generalizing k with
-  | nil => simp
-  | cons a as ih =>
-    simp [ih, List.foldlM_cons]
-
-/-! ### foldlM and foldrM -/
-
-theorem foldlM_map [Monad m] (f : β₁ → β₂) (g : α → β₂ → m α) (l : Array β₁) (init : α) :
-    (l.map f).foldlM g init = l.foldlM (fun x y => g x (f y)) init := by
-  cases l
-  rw [List.map_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldlM_map]
-
-theorem foldrM_map [Monad m] [LawfulMonad m] (f : β₁ → β₂) (g : β₂ → α → m α) (l : Array β₁)
-    (init : α) : (l.map f).foldrM g init = l.foldrM (fun x y => g (f x) y) init := by
-  cases l
-  rw [List.map_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldrM_map]
-
-theorem foldlM_filterMap [Monad m] [LawfulMonad m] (f : α → Option β) (g : γ → β → m γ) (l : Array α) (init : γ) :
-    (l.filterMap f).foldlM g init =
-      l.foldlM (fun x y => match f y with | some b => g x b | none => pure x) init := by
-  cases l
-  rw [List.filterMap_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldlM_filterMap]
-  rfl
-
-theorem foldrM_filterMap [Monad m] [LawfulMonad m] (f : α → Option β) (g : β → γ → m γ) (l : Array α) (init : γ) :
-    (l.filterMap f).foldrM g init =
-      l.foldrM (fun x y => match f x with | some b => g b y | none => pure y) init := by
-  cases l
-  rw [List.filterMap_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldrM_filterMap]
-  rfl
-
-theorem foldlM_filter [Monad m] [LawfulMonad m] (p : α → Bool) (g : β → α → m β) (l : Array α) (init : β) :
-    (l.filter p).foldlM g init =
-      l.foldlM (fun x y => if p y then g x y else pure x) init := by
-  cases l
-  rw [List.filter_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldlM_filter]
-
-theorem foldrM_filter [Monad m] [LawfulMonad m] (p : α → Bool) (g : α → β → m β) (l : Array α) (init : β) :
-    (l.filter p).foldrM g init =
-      l.foldrM (fun x y => if p x then g x y else pure y) init := by
-  cases l
-  rw [List.filter_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldrM_filter]
-
-/-! ### forIn' -/
-
-/--
-We can express a for loop over an array as a fold,
-in which whenever we reach `.done b` we keep that value through the rest of the fold.
--/
-theorem forIn'_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : Array α) (f : (a : α) → a ∈ l → β → m (ForInStep β)) (init : β) :
-    forIn' l init f = ForInStep.value <$>
-      l.attach.foldlM (fun b ⟨a, m⟩ => match b with
-        | .yield b => f a m b
-        | .done b => pure (.done b)) (ForInStep.yield init) := by
-  cases l
-  rw [List.attach_toArray] -- Why doesn't this fire via `simp`?
-  simp only [List.forIn'_toArray, List.forIn'_eq_foldlM, List.attachWith_mem_toArray, size_toArray,
-    List.length_map, List.length_attach, List.foldlM_toArray', List.foldlM_map]
-  congr
-
-/-- We can express a for loop over an array which always yields as a fold. -/
-@[simp] theorem forIn'_yield_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : Array α) (f : (a : α) → a ∈ l → β → m γ) (g : (a : α) → a ∈ l → β → γ → β) (init : β) :
-    forIn' l init (fun a m b => (fun c => .yield (g a m b c)) <$> f a m b) =
-      l.attach.foldlM (fun b ⟨a, m⟩ => g a m b <$> f a m b) init := by
-  cases l
-  rw [List.attach_toArray] -- Why doesn't this fire via `simp`?
-  simp [List.foldlM_map]
-
-theorem forIn'_pure_yield_eq_foldl [Monad m] [LawfulMonad m]
-    (l : Array α) (f : (a : α) → a ∈ l → β → β) (init : β) :
-    forIn' l init (fun a m b => pure (.yield (f a m b))) =
-      pure (f := m) (l.attach.foldl (fun b ⟨a, h⟩ => f a h b) init) := by
-  cases l
-  simp [List.forIn'_pure_yield_eq_foldl, List.foldl_map]
-
-@[simp] theorem forIn'_yield_eq_foldl
-    (l : Array α) (f : (a : α) → a ∈ l → β → β) (init : β) :
-    forIn' (m := Id) l init (fun a m b => .yield (f a m b)) =
-      l.attach.foldl (fun b ⟨a, h⟩ => f a h b) init := by
-  cases l
-  simp [List.foldl_map]
-
-/--
-We can express a for loop over an array as a fold,
-in which whenever we reach `.done b` we keep that value through the rest of the fold.
--/
-theorem forIn_eq_foldlM [Monad m] [LawfulMonad m]
-    (f : α → β → m (ForInStep β)) (init : β) (l : Array α) :
-    forIn l init f = ForInStep.value <$>
-      l.foldlM (fun b a => match b with
-        | .yield b => f a b
-        | .done b => pure (.done b)) (ForInStep.yield init) := by
-  cases l
-  simp only [List.forIn_toArray, List.forIn_eq_foldlM, size_toArray, List.foldlM_toArray']
-  congr
-
-/-- We can express a for loop over an array which always yields as a fold. -/
-@[simp] theorem forIn_yield_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : Array α) (f : α → β → m γ) (g : α → β → γ → β) (init : β) :
-    forIn l init (fun a b => (fun c => .yield (g a b c)) <$> f a b) =
-      l.foldlM (fun b a => g a b <$> f a b) init := by
-  cases l
-  simp [List.foldlM_map]
-
-theorem forIn_pure_yield_eq_foldl [Monad m] [LawfulMonad m]
-    (l : Array α) (f : α → β → β) (init : β) :
-    forIn l init (fun a b => pure (.yield (f a b))) =
-      pure (f := m) (l.foldl (fun b a => f a b) init) := by
-  cases l
-  simp [List.forIn_pure_yield_eq_foldl, List.foldl_map]
-
-@[simp] theorem forIn_yield_eq_foldl
-    (l : Array α) (f : α → β → β) (init : β) :
-    forIn (m := Id) l init (fun a b => .yield (f a b)) =
-      l.foldl (fun b a => f a b) init := by
-  cases l
-  simp [List.foldl_map]
-
-end Array

src/Init/Data/Array/QSort.lean

@@ -5,7 +5,6 @@ Authors: Leonardo de Moura
 -/
 prelude
 import Init.Data.Array.Basic
-import Init.Data.Ord
 
 namespace Array
 -- TODO: remove the [Inhabited α] parameters as soon as we have the tactic framework for automating proof generation and using Array.fget
@@ -45,11 +44,4 @@ def qpartition (as : Array α) (lt : α → α → Bool) (lo hi : Nat) : Nat ×
     else as
   sort as low high
 
-set_option linter.unusedVariables.funArgs false in
-/--
-Sort an array using `compare` to compare elements.
--/
-def qsortOrd [ord : Ord α] (xs : Array α) : Array α :=
-  xs.qsort fun x y => compare x y |>.isLT
-
 end Array

src/Init/Data/Array/Set.lean

@@ -1,39 +0,0 @@
-/-
-Copyright (c) 2020 Microsoft Corporation. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Leonardo de Moura, Mario Carneiro
--/
-prelude
-import Init.Tactics
-
-
-/--
-Set an element in an array, using a proof that the index is in bounds.
-(This proof can usually be omitted, and will be synthesized automatically.)
-
-This will perform the update destructively provided that `a` has a reference
-count of 1 when called.
--/
-@[extern "lean_array_fset"]
-def Array.set (a : Array α) (i : @& Nat) (v : α) (h : i < a.size := by get_elem_tactic) :
-    Array α where
-  toList := a.toList.set i v
-
-/--
-Set an element in an array, or do nothing if the index is out of bounds.
-
-This will perform the update destructively provided that `a` has a reference
-count of 1 when called.
--/
-@[inline] def Array.setD (a : Array α) (i : Nat) (v : α) : Array α :=
-  dite (LT.lt i a.size) (fun h => a.set i v h) (fun _ => a)
-
-/--
-Set an element in an array, or panic if the index is out of bounds.
-
-This will perform the update destructively provided that `a` has a reference
-count of 1 when called.
--/
-@[extern "lean_array_set"]
-def Array.set! (a : Array α) (i : @& Nat) (v : α) : Array α :=
-  Array.setD a i v

src/Init/Data/Array/Subarray.lean

@@ -15,6 +15,15 @@ structure Subarray (α : Type u)  where
   start_le_stop : start ≤ stop
   stop_le_array_size : stop ≤ array.size
 
+@[deprecated Subarray.array (since := "2024-04-13")]
+abbrev Subarray.as (s : Subarray α) : Array α := s.array
+
+@[deprecated Subarray.start_le_stop (since := "2024-04-13")]
+theorem Subarray.h₁ (s : Subarray α) : s.start ≤ s.stop := s.start_le_stop
+
+@[deprecated Subarray.stop_le_array_size (since := "2024-04-13")]
+theorem Subarray.h₂ (s : Subarray α) : s.stop ≤ s.array.size := s.stop_le_array_size
+
 namespace Subarray
 
 def size (s : Subarray α) : Nat :=
@@ -39,7 +48,7 @@ instance : GetElem (Subarray α) Nat α fun xs i => i < xs.size where
   getElem xs i h := xs.get ⟨i, h⟩
 
 @[inline] def getD (s : Subarray α) (i : Nat) (v₀ : α) : α :=
-  if h : i < s.size then s[i] else v₀
+  if h : i < s.size then s.get ⟨i, h⟩ else v₀
 
 abbrev get! [Inhabited α] (s : Subarray α) (i : Nat) : α :=
   getD s i default
@@ -50,22 +59,6 @@ def popFront (s : Subarray α) : Subarray α :=
   else
     s
 
-/--
-The empty subarray.
--/
-protected def empty : Subarray α where
-  array := #[]
-  start := 0
-  stop := 0
-  start_le_stop := Nat.le_refl 0
-  stop_le_array_size := Nat.le_refl 0
-
-instance : EmptyCollection (Subarray α) :=
-  ⟨Subarray.empty⟩
-
-instance : Inhabited (Subarray α) :=
-  ⟨{}⟩
-
 @[inline] unsafe def forInUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (s : Subarray α) (b : β) (f : α → β → m (ForInStep β)) : m β :=
   let sz := USize.ofNat s.stop
   let rec @[specialize] loop (i : USize) (b : β) : m β := do

src/Init/Data/Array/TakeDrop.lean

@@ -5,14 +5,13 @@ Authors: Markus Himmel
 -/
 prelude
 import Init.Data.Array.Lemmas
-import Init.Data.List.Nat.TakeDrop
+import Init.Data.List.TakeDrop
 
 namespace Array
 
 theorem exists_of_uset (self : Array α) (i d h) :
-    ∃ l₁ l₂, self.toList = l₁ ++ self[i] :: l₂ ∧ List.length l₁ = i.toNat ∧
-      (self.uset i d h).toList = l₁ ++ d :: l₂ := by
-  simpa only [ugetElem_eq_getElem, getElem_eq_getElem_toList, uset, toList_set] using
-    List.exists_of_set _
+    ∃ l₁ l₂, self.data = l₁ ++ self[i] :: l₂ ∧ List.length l₁ = i.toNat ∧
+      (self.uset i d h).data = l₁ ++ d :: l₂ := by
+  simpa [Array.getElem_eq_data_getElem] using List.exists_of_set _
 
 end Array

src/Init/Data/BEq.lean

@@ -56,5 +56,5 @@ theorem BEq.neq_of_beq_of_neq [BEq α] [PartialEquivBEq α] {a b c : α} :
 
 instance (priority := low) [BEq α] [LawfulBEq α] : EquivBEq α where
   refl := LawfulBEq.rfl
-  symm h := beq_iff_eq.2 <| Eq.symm <| beq_iff_eq.1 h
-  trans hab hbc := beq_iff_eq.2 <| (beq_iff_eq.1 hab).trans <| beq_iff_eq.1 hbc
+  symm h := (beq_iff_eq _ _).2 <| Eq.symm <| (beq_iff_eq _ _).1 h
+  trans hab hbc := (beq_iff_eq _ _).2 <| ((beq_iff_eq _ _).1 hab).trans <| (beq_iff_eq _ _).1 hbc

src/Init/Data/BitVec.lean

@@ -1,7 +1,7 @@
 /-
 Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Kim Morrison
+Authors: Scott Morrison
 -/
 prelude
 import Init.Data.BitVec.Basic

src/Init/Data/BitVec/Basic.lean

@@ -1,34 +1,82 @@
 /-
 Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Joe Hendrix, Wojciech Nawrocki, Leonardo de Moura, Mario Carneiro, Alex Keizer, Harun Khan, Abdalrhman M Mohamed, Siddharth Bhat
+Authors: Joe Hendrix, Wojciech Nawrocki, Leonardo de Moura, Mario Carneiro, Alex Keizer, Harun Khan, Abdalrhman M Mohamed
 -/
 prelude
 import Init.Data.Fin.Basic
 import Init.Data.Nat.Bitwise.Lemmas
 import Init.Data.Nat.Power2
 import Init.Data.Int.Bitwise
-import Init.Data.BitVec.BasicAux
 
 /-!
-We define the basic algebraic structure of bitvectors. We choose the `Fin` representation over
-others for its relative efficiency (Lean has special support for `Nat`),  and the fact that bitwise
-operations on `Fin` are already defined. Some other possible representations are `List Bool`,
-`{ l : List Bool // l.length = w }`, `Fin w → Bool`.
+We define bitvectors. We choose the `Fin` representation over others for its relative efficiency
+(Lean has special support for `Nat`), alignment with `UIntXY` types which are also represented
+with `Fin`, and the fact that bitwise operations on `Fin` are already defined. Some other possible
+representations are `List Bool`, `{ l : List Bool // l.length = w }`, `Fin w → Bool`.
 
 We define many of the bitvector operations from the
 [`QF_BV` logic](https://smtlib.cs.uiowa.edu/logics-all.shtml#QF_BV).
 of SMT-LIBv2.
 -/
 
-set_option linter.missingDocs true
+/--
+A bitvector of the specified width.
+
+This is represented as the underlying `Nat` number in both the runtime
+and the kernel, inheriting all the special support for `Nat`.
+-/
+structure BitVec (w : Nat) where
+  /-- Construct a `BitVec w` from a number less than `2^w`.
+  O(1), because we use `Fin` as the internal representation of a bitvector. -/
+  ofFin ::
+  /-- Interpret a bitvector as a number less than `2^w`.
+  O(1), because we use `Fin` as the internal representation of a bitvector. -/
+  toFin : Fin (2^w)
+
+@[deprecated (since := "2024-04-12")]
+protected abbrev Std.BitVec := _root_.BitVec
+
+-- We manually derive the `DecidableEq` instances for `BitVec` because
+-- we want to have builtin support for bit-vector literals, and we
+-- need a name for this function to implement `canUnfoldAtMatcher` at `WHNF.lean`.
+def BitVec.decEq (a b : BitVec n) : Decidable (a = b) :=
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ =>
+    if h : n = m then
+      isTrue (h ▸ rfl)
+    else
+      isFalse (fun h' => BitVec.noConfusion h' (fun h' => absurd h' h))
+
+instance : DecidableEq (BitVec n) := BitVec.decEq
 
 namespace BitVec
 
 section Nat
 
+/-- The `BitVec` with value `i`, given a proof that `i < 2^n`. -/
+@[match_pattern]
+protected def ofNatLt {n : Nat} (i : Nat) (p : i < 2^n) : BitVec n where
+  toFin := ⟨i, p⟩
+
+/-- The `BitVec` with value `i mod 2^n`. -/
+@[match_pattern]
+protected def ofNat (n : Nat) (i : Nat) : BitVec n where
+  toFin := Fin.ofNat' i (Nat.two_pow_pos n)
+
+instance instOfNat : OfNat (BitVec n) i where ofNat := .ofNat n i
 instance natCastInst : NatCast (BitVec w) := ⟨BitVec.ofNat w⟩
 
+/-- Given a bitvector `a`, return the underlying `Nat`. This is O(1) because `BitVec` is a
+(zero-cost) wrapper around a `Nat`. -/
+protected def toNat (a : BitVec n) : Nat := a.toFin.val
+
+/-- Return the bound in terms of toNat. -/
+theorem isLt (x : BitVec w) : x.toNat < 2^w := x.toFin.isLt
+
+@[deprecated isLt (since := "2024-03-12")]
+theorem toNat_lt (x : BitVec n) : x.toNat < 2^n := x.isLt
+
 /-- Theorem for normalizing the bit vector literal representation. -/
 -- TODO: This needs more usage data to assess which direction the simp should go.
 @[simp, bv_toNat] theorem ofNat_eq_ofNat : @OfNat.ofNat (BitVec n) i _ = .ofNat n i := rfl
@@ -66,76 +114,25 @@ end zero_allOnes
 
 section getXsb
 
-/--
-Return the `i`-th least significant bit.
-
-This will be renamed `getLsb` after the existing deprecated alias is removed.
--/
-@[inline] def getLsb' (x : BitVec w) (i : Fin w) : Bool := x.toNat.testBit i
-
-/-- Return the `i`-th least significant bit or `none` if `i ≥ w`. -/
-@[inline] def getLsb? (x : BitVec w) (i : Nat) : Option Bool :=
-  if h : i < w then some (getLsb' x ⟨i, h⟩) else none
-
-/--
-Return the `i`-th most significant bit.
-
-This will be renamed `getMsb` after the existing deprecated alias is removed.
--/
-@[inline] def getMsb' (x : BitVec w) (i : Fin w) : Bool := x.getLsb' ⟨w-1-i, by omega⟩
-
-/-- Return 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
-
 /-- Return the `i`-th least significant bit or `false` if `i ≥ w`. -/
-@[inline] def getLsbD (x : BitVec w) (i : Nat) : Bool :=
-  x.toNat.testBit i
-
-@[deprecated getLsbD (since := "2024-08-29"), inherit_doc getLsbD]
-def getLsb (x : BitVec w) (i : Nat) : Bool := x.getLsbD i
+@[inline] def getLsb (x : BitVec w) (i : Nat) : Bool := x.toNat.testBit i
 
 /-- Return the `i`-th most significant bit or `false` if `i ≥ w`. -/
-@[inline] def getMsbD (x : BitVec w) (i : Nat) : Bool :=
-  i < w && x.getLsbD (w-1-i)
-
-@[deprecated getMsbD (since := "2024-08-29"), inherit_doc getMsbD]
-def getMsb (x : BitVec w) (i : Nat) : Bool := x.getMsbD i
+@[inline] def getMsb (x : BitVec w) (i : Nat) : Bool := i < w && getLsb x (w-1-i)
 
 /-- Return most-significant bit in bitvector. -/
-@[inline] protected def msb (x : BitVec n) : Bool := getMsbD x 0
+@[inline] protected def msb (a : BitVec n) : Bool := getMsb a 0
 
 end getXsb
 
-section getElem
-
-instance : GetElem (BitVec w) Nat Bool fun _ i => i < w where
-  getElem xs i h := xs.getLsb' ⟨i, h⟩
-
-/-- We prefer `x[i]` as the simp normal form for `getLsb'` -/
-@[simp] theorem getLsb'_eq_getElem (x : BitVec w) (i : Fin w) :
-    x.getLsb' i = x[i] := rfl
-
-/-- We prefer `x[i]?` as the simp normal form for `getLsb?` -/
-@[simp] theorem getLsb?_eq_getElem? (x : BitVec w) (i : Nat) :
-    x.getLsb? i = x[i]? := rfl
-
-theorem getElem_eq_testBit_toNat (x : BitVec w) (i : Nat) (h : i < w) :
-  x[i] = x.toNat.testBit i := rfl
-
-theorem getLsbD_eq_getElem {x : BitVec w} {i : Nat} (h : i < w) :
-    x.getLsbD i = x[i] := rfl
-
-end getElem
-
 section Int
 
 /-- Interpret the bitvector as an integer stored in two's complement form. -/
-protected def toInt (x : BitVec n) : Int :=
-  if 2 * x.toNat < 2^n then
-    x.toNat
+protected def toInt (a : BitVec n) : Int :=
+  if 2 * a.toNat < 2^n then
+    a.toNat
   else
-    (x.toNat : Int) - (2^n : Nat)
+    (a.toNat : Int) - (2^n : Nat)
 
 /-- The `BitVec` with value `(2^n + (i mod 2^n)) mod 2^n`.  -/
 protected def ofInt (n : Nat) (i : Int) : BitVec n := .ofNatLt (i % (Int.ofNat (2^n))).toNat (by
@@ -188,6 +185,22 @@ end repr_toString
 
 section arithmetic
 
+/--
+Addition for bit vectors. This can be interpreted as either signed or unsigned addition
+modulo `2^n`.
+
+SMT-Lib name: `bvadd`.
+-/
+protected def add (x y : BitVec n) : BitVec n := .ofNat n (x.toNat + y.toNat)
+instance : Add (BitVec n) := ⟨BitVec.add⟩
+
+/--
+Subtraction for bit vectors. This can be interpreted as either signed or unsigned subtraction
+modulo `2^n`.
+-/
+protected def sub (x y : BitVec n) : BitVec n := .ofNat n ((2^n - y.toNat) + x.toNat)
+instance : Sub (BitVec n) := ⟨BitVec.sub⟩
+
 /--
 Negation for bit vectors. This can be interpreted as either signed or unsigned negation
 modulo `2^n`.
@@ -200,11 +213,11 @@ instance : Neg (BitVec n) := ⟨.neg⟩
 /--
 Return the absolute value of a signed bitvector.
 -/
-protected def abs (x : BitVec n) : BitVec n := if x.msb then .neg x else x
+protected def abs (s : BitVec n) : BitVec n := if s.msb then .neg s else s
 
 /--
-Multiplication for bit vectors. This can be interpreted as either signed or unsigned
-multiplication modulo `2^n`.
+Multiplication for bit vectors. This can be interpreted as either signed or unsigned negation
+modulo `2^n`.
 
 SMT-Lib name: `bvmul`.
 -/
@@ -247,12 +260,12 @@ sdiv 5#4 -2 = -2#4
 sdiv (-7#4) (-2) = 3#4
 ```
 -/
-def sdiv (x y : BitVec n) : BitVec n :=
-  match x.msb, y.msb with
-  | false, false => udiv x y
-  | false, true  => .neg (udiv x (.neg y))
-  | true,  false => .neg (udiv (.neg x) y)
-  | true,  true  => udiv (.neg x) (.neg y)
+def sdiv (s t : BitVec n) : BitVec n :=
+  match s.msb, t.msb with
+  | false, false => udiv s t
+  | false, true  => .neg (udiv s (.neg t))
+  | true,  false => .neg (udiv (.neg s) t)
+  | true,  true  => udiv (.neg s) (.neg t)
 
 /--
 Signed division for bit vectors using SMTLIB rules for division by zero.
@@ -261,40 +274,40 @@ Specifically, `smtSDiv x 0 = if x >= 0 then -1 else 1`
 
 SMT-Lib name: `bvsdiv`.
 -/
-def smtSDiv (x y : BitVec n) : BitVec n :=
-  match x.msb, y.msb with
-  | false, false => smtUDiv x y
-  | false, true  => .neg (smtUDiv x (.neg y))
-  | true,  false => .neg (smtUDiv (.neg x) y)
-  | true,  true  => smtUDiv (.neg x) (.neg y)
+def smtSDiv (s t : BitVec n) : BitVec n :=
+  match s.msb, t.msb with
+  | false, false => smtUDiv s t
+  | false, true  => .neg (smtUDiv s (.neg t))
+  | true,  false => .neg (smtUDiv (.neg s) t)
+  | true,  true  => smtUDiv (.neg s) (.neg t)
 
 /--
 Remainder for signed division rounding to zero.
 
 SMT_Lib name: `bvsrem`.
 -/
-def srem (x y : BitVec n) : BitVec n :=
-  match x.msb, y.msb with
-  | false, false => umod x y
-  | false, true  => umod x (.neg y)
-  | true,  false => .neg (umod (.neg x) y)
-  | true,  true  => .neg (umod (.neg x) (.neg y))
+def srem (s t : BitVec n) : BitVec n :=
+  match s.msb, t.msb with
+  | false, false => umod s t
+  | false, true  => umod s (.neg t)
+  | true,  false => .neg (umod (.neg s) t)
+  | true,  true  => .neg (umod (.neg s) (.neg t))
 
 /--
 Remainder for signed division rounded to negative infinity.
 
 SMT_Lib name: `bvsmod`.
 -/
-def smod (x y : BitVec m) : BitVec m :=
-  match x.msb, y.msb with
-  | false, false => umod x y
+def smod (s t : BitVec m) : BitVec m :=
+  match s.msb, t.msb with
+  | false, false => umod s t
   | false, true =>
-    let u := umod x (.neg y)
-    (if u = .zero m then u else .add u y)
+    let u := umod s (.neg t)
+    (if u = .zero m then u else .add u t)
   | true, false =>
-    let u := umod (.neg x) y
-    (if u = .zero m then u else .sub y u)
-  | true, true => .neg (umod (.neg x) (.neg y))
+    let u := umod (.neg s) t
+    (if u = .zero m then u else .sub t u)
+  | true, true => .neg (umod (.neg s) (.neg t))
 
 end arithmetic
 
@@ -321,6 +334,10 @@ SMT-Lib name: `bvult`.
 -/
 protected def ult (x y : BitVec n) : Bool := x.toNat < y.toNat
 
+instance : LT (BitVec n) where lt := (·.toNat < ·.toNat)
+instance (x y : BitVec n) : Decidable (x < y) :=
+  inferInstanceAs (Decidable (x.toNat < y.toNat))
+
 /--
 Unsigned less-than-or-equal-to for bit vectors.
 
@@ -328,6 +345,10 @@ SMT-Lib name: `bvule`.
 -/
 protected def ule (x y : BitVec n) : Bool := x.toNat ≤ y.toNat
 
+instance : LE (BitVec n) where le := (·.toNat ≤ ·.toNat)
+instance (x y : BitVec n) : Decidable (x ≤ y) :=
+  inferInstanceAs (Decidable (x.toNat ≤ y.toNat))
+
 /--
 Signed less-than for bit vectors.
 
@@ -350,8 +371,8 @@ end relations
 
 section cast
 
-/-- `cast eq x` embeds `x` into an equal `BitVec` type. -/
-@[inline] def cast (eq : n = m) (x : BitVec n) : BitVec m := .ofNatLt x.toNat (eq ▸ x.isLt)
+/-- `cast eq i` embeds `i` into an equal `BitVec` type. -/
+@[inline] def cast (eq : n = m) (i : BitVec n) : BitVec m := .ofNatLt i.toNat (eq ▸ i.isLt)
 
 @[simp] theorem cast_ofNat {n m : Nat} (h : n = m) (x : Nat) :
     cast h (BitVec.ofNat n x) = BitVec.ofNat m x := by
@@ -368,7 +389,7 @@ Extraction of bits `start` to `start + len - 1` from a bit vector of size `n` to
 new bitvector of size `len`. If `start + len > n`, then the vector will be zero-padded in the
 high bits.
 -/
-def extractLsb' (start len : Nat) (x : BitVec n) : BitVec len := .ofNat _ (x.toNat >>> start)
+def extractLsb' (start len : Nat) (a : BitVec n) : BitVec len := .ofNat _ (a.toNat >>> start)
 
 /--
 Extraction of bits `hi` (inclusive) down to `lo` (inclusive) from a bit vector of size `n` to
@@ -376,59 +397,44 @@ yield a new bitvector of size `hi - lo + 1`.
 
 SMT-Lib name: `extract`.
 -/
-def extractLsb (hi lo : Nat) (x : BitVec n) : BitVec (hi - lo + 1) := extractLsb' lo _ x
+def extractLsb (hi lo : Nat) (a : BitVec n) : BitVec (hi - lo + 1) := extractLsb' lo _ a
 
 /--
-A version of `setWidth` that requires a proof, but is a noop.
+A version of `zeroExtend` that requires a proof, but is a noop.
 -/
-def setWidth' {n w : Nat} (le : n ≤ w) (x : BitVec n) : BitVec w :=
+def zeroExtend' {n w : Nat} (le : n ≤ w) (x : BitVec n)  : BitVec w :=
   x.toNat#'(by
     apply Nat.lt_of_lt_of_le x.isLt
     exact Nat.pow_le_pow_of_le_right (by trivial) le)
 
-@[deprecated setWidth' (since := "2024-09-18"), inherit_doc setWidth'] abbrev zeroExtend' := @setWidth'
-
 /--
 `shiftLeftZeroExtend x n` returns `zeroExtend (w+n) x <<< n` without
 needing to compute `x % 2^(2+n)`.
 -/
-def shiftLeftZeroExtend (msbs : BitVec w) (m : Nat) : BitVec (w + m) :=
-  let shiftLeftLt {x : Nat} (p : x < 2^w) (m : Nat) : x <<< m < 2^(w + m) := by
+def shiftLeftZeroExtend (msbs : BitVec w) (m : Nat) : BitVec (w+m) :=
+  let shiftLeftLt {x : Nat} (p : x < 2^w) (m : Nat) : x <<< m < 2^(w+m) := by
         simp [Nat.shiftLeft_eq, Nat.pow_add]
         apply Nat.mul_lt_mul_of_pos_right p
         exact (Nat.two_pow_pos m)
   (msbs.toNat <<< m)#'(shiftLeftLt msbs.isLt m)
 
 /--
-Transform `x` of length `w` into a bitvector of length `v`, by either:
-- zero extending, that is, adding zeros in the high bits until it has length `v`, if `v > w`, or
-- truncating the high bits, if `v < w`.
+Zero extend vector `x` of length `w` by adding zeros in the high bits until it has length `v`.
+If `v < w` then it truncates the high bits instead.
 
 SMT-Lib name: `zero_extend`.
 -/
-def setWidth (v : Nat) (x : BitVec w) : BitVec v :=
+def zeroExtend (v : Nat) (x : BitVec w) : BitVec v :=
   if h : w ≤ v then
-    setWidth' h x
+    zeroExtend' h x
   else
     .ofNat v x.toNat
 
 /--
-Transform `x` of length `w` into a bitvector of length `v`, by either:
-- zero extending, that is, adding zeros in the high bits until it has length `v`, if `v > w`, or
-- truncating the high bits, if `v < w`.
-
-SMT-Lib name: `zero_extend`.
+Truncate the high bits of bitvector `x` of length `w`, resulting in a vector of length `v`.
+If `v > w` then it zero-extends the vector instead.
 -/
-abbrev zeroExtend := @setWidth
-
-/--
-Transform `x` of length `w` into a bitvector of length `v`, by either:
-- zero extending, that is, adding zeros in the high bits until it has length `v`, if `v > w`, or
-- truncating the high bits, if `v < w`.
-
-SMT-Lib name: `zero_extend`.
--/
-abbrev truncate := @setWidth
+abbrev truncate := @zeroExtend
 
 /--
 Sign extend a vector of length `w`, extending with `i` additional copies of the most significant
@@ -494,24 +500,24 @@ instance : Complement (BitVec w) := ⟨.not⟩
 
 /--
 Left shift for bit vectors. The low bits are filled with zeros. As a numeric operation, this is
-equivalent to `x * 2^s`, modulo `2^n`.
+equivalent to `a * 2^s`, modulo `2^n`.
 
 SMT-Lib name: `bvshl` except this operator uses a `Nat` shift value.
 -/
-protected def shiftLeft (x : BitVec n) (s : Nat) : BitVec n := BitVec.ofNat n (x.toNat <<< s)
+protected def shiftLeft (a : BitVec n) (s : Nat) : BitVec n := BitVec.ofNat n (a.toNat <<< s)
 instance : HShiftLeft (BitVec w) Nat (BitVec w) := ⟨.shiftLeft⟩
 
 /--
 (Logical) right shift for bit vectors. The high bits are filled with zeros.
-As a numeric operation, this is equivalent to `x / 2^s`, rounding down.
+As a numeric operation, this is equivalent to `a / 2^s`, rounding down.
 
 SMT-Lib name: `bvlshr` except this operator uses a `Nat` shift value.
 -/
-def ushiftRight (x : BitVec n) (s : Nat) : BitVec n :=
-  (x.toNat >>> s)#'(by
-  let ⟨x, lt⟩ := x
+def ushiftRight (a : BitVec n) (s : Nat) : BitVec n :=
+  (a.toNat >>> s)#'(by
+  let ⟨a, lt⟩ := a
   simp only [BitVec.toNat, Nat.shiftRight_eq_div_pow, Nat.div_lt_iff_lt_mul (Nat.two_pow_pos s)]
-  rw [←Nat.mul_one x]
+  rw [←Nat.mul_one a]
   exact Nat.mul_lt_mul_of_lt_of_le' lt (Nat.two_pow_pos s) (Nat.le_refl 1))
 
 instance : HShiftRight (BitVec w) Nat (BitVec w) := ⟨.ushiftRight⟩
@@ -519,24 +525,15 @@ instance : HShiftRight (BitVec w) Nat (BitVec w) := ⟨.ushiftRight⟩
 /--
 Arithmetic right shift for bit vectors. The high bits are filled with the
 most-significant bit.
-As a numeric operation, this is equivalent to `x.toInt >>> s`.
+As a numeric operation, this is equivalent to `a.toInt >>> s`.
 
 SMT-Lib name: `bvashr` except this operator uses a `Nat` shift value.
 -/
-def sshiftRight (x : BitVec n) (s : Nat) : BitVec n := .ofInt n (x.toInt >>> s)
+def sshiftRight (a : BitVec n) (s : Nat) : BitVec n := .ofInt n (a.toInt >>> s)
 
 instance {n} : HShiftLeft  (BitVec m) (BitVec n) (BitVec m) := ⟨fun x y => x <<< y.toNat⟩
 instance {n} : HShiftRight (BitVec m) (BitVec n) (BitVec m) := ⟨fun x y => x >>> y.toNat⟩
 
-/--
-Arithmetic right shift for bit vectors. The high bits are filled with the
-most-significant bit.
-As a numeric operation, this is equivalent to `a.toInt >>> s.toNat`.
-
-SMT-Lib name: `bvashr`.
--/
-def sshiftRight' (a : BitVec n) (s : BitVec m) : BitVec n := a.sshiftRight s.toNat
-
 /-- Auxiliary function for `rotateLeft`, which does not take into account the case where
 the rotation amount is greater than the bitvector width. -/
 def rotateLeftAux (x : BitVec w) (n : Nat) : BitVec w :=
@@ -579,16 +576,18 @@ input is on the left, so `0xAB#8 ++ 0xCD#8 = 0xABCD#16`.
 SMT-Lib name: `concat`.
 -/
 def append (msbs : BitVec n) (lsbs : BitVec m) : BitVec (n+m) :=
-  shiftLeftZeroExtend msbs m ||| setWidth' (Nat.le_add_left m n) lsbs
+  shiftLeftZeroExtend msbs m ||| zeroExtend' (Nat.le_add_left m n) lsbs
 
 instance : HAppend (BitVec w) (BitVec v) (BitVec (w + v)) := ⟨.append⟩
 
 -- TODO: write this using multiplication
 /-- `replicate i x` concatenates `i` copies of `x` into a new vector of length `w*i`. -/
 def replicate : (i : Nat) → BitVec w → BitVec (w*i)
-  | 0,   _ => 0#0
+  | 0,   _ => 0
   | n+1, x =>
-    (x ++ replicate n x).cast (by rw [Nat.mul_succ]; omega)
+    have hEq : w + w*n = w*(n + 1) := by
+      rw [Nat.mul_add, Nat.add_comm, Nat.mul_one]
+    hEq ▸ (x ++ replicate n x)
 
 /-!
 ### Cons and Concat
@@ -602,13 +601,6 @@ result of appending a single bit to the front in the naive implementation).
     That is, the new bit is the least significant bit. -/
 def concat {n} (msbs : BitVec n) (lsb : Bool) : BitVec (n+1) := msbs ++ (ofBool lsb)
 
-/--
-`x.shiftConcat b` shifts all bits of `x` to the left by `1` and sets the least significant bit to `b`.
-It is a non-dependent version of `concat` that does not change the total bitwidth.
--/
-def shiftConcat (x : BitVec n) (b : Bool) : BitVec n :=
-  (x.concat b).truncate n
-
 /-- Prepend a single bit to the front of a bitvector, using big endian order (see `append`).
     That is, the new bit is the most significant bit. -/
 def cons {n} (msb : Bool) (lsbs : BitVec n) : BitVec (n+1) :=
@@ -631,16 +623,6 @@ def twoPow (w : Nat) (i : Nat) : BitVec w := 1#w <<< i
 
 end bitwise
 
-/-- Compute a hash of a bitvector, combining 64-bit words using `mixHash`. -/
-def hash (bv : BitVec n) : UInt64 :=
-  if n ≤ 64 then
-    bv.toFin.val.toUInt64
-  else
-    mixHash (bv.toFin.val.toUInt64) (hash ((bv >>> 64).setWidth (n - 64)))
-
-instance : Hashable (BitVec n) where
-  hash := hash
-
 section normalization_eqs
 /-! We add simp-lemmas that rewrite bitvector operations into the equivalent notation -/
 @[simp] theorem append_eq (x : BitVec w) (y : BitVec v)   : BitVec.append x y = x ++ y        := rfl
@@ -654,8 +636,6 @@ section normalization_eqs
 @[simp] theorem add_eq (x y : BitVec w)                   : BitVec.add x y = x + y            := rfl
 @[simp] theorem sub_eq (x y : BitVec w)                   : BitVec.sub x y = x - y            := rfl
 @[simp] theorem mul_eq (x y : BitVec w)                   : BitVec.mul x y = x * y            := rfl
-@[simp] theorem udiv_eq (x y : BitVec w)                  : BitVec.udiv x y = x / y           := rfl
-@[simp] theorem umod_eq (x y : BitVec w)                  : BitVec.umod x y = x % y           := rfl
 @[simp] theorem zero_eq                                   : BitVec.zero n = 0#n               := rfl
 end normalization_eqs
 

src/Init/Data/BitVec/BasicAux.lean

@@ -1,52 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Joe Hendrix, Wojciech Nawrocki, Leonardo de Moura, Mario Carneiro, Alex Keizer, Harun Khan, Abdalrhman M Mohamed
--/
-prelude
-import Init.Data.Fin.Basic
-
-set_option linter.missingDocs true
-
-/-!
-This module exists to provide the very basic `BitVec` definitions required for
-`Init.Data.UInt.BasicAux`.
--/
-
-namespace BitVec
-
-section Nat
-
-/-- The `BitVec` with value `i mod 2^n`. -/
-@[match_pattern]
-protected def ofNat (n : Nat) (i : Nat) : BitVec n where
-  toFin := Fin.ofNat' (2^n) i
-
-instance instOfNat : OfNat (BitVec n) i where ofNat := .ofNat n i
-
-/-- Return the bound in terms of toNat. -/
-theorem isLt (x : BitVec w) : x.toNat < 2^w := x.toFin.isLt
-
-end Nat
-
-section arithmetic
-
-/--
-Addition for bit vectors. This can be interpreted as either signed or unsigned addition
-modulo `2^n`.
-
-SMT-Lib name: `bvadd`.
--/
-protected def add (x y : BitVec n) : BitVec n := .ofNat n (x.toNat + y.toNat)
-instance : Add (BitVec n) := ⟨BitVec.add⟩
-
-/--
-Subtraction for bit vectors. This can be interpreted as either signed or unsigned subtraction
-modulo `2^n`.
--/
-protected def sub (x y : BitVec n) : BitVec n := .ofNat n ((2^n - y.toNat) + x.toNat)
-instance : Sub (BitVec n) := ⟨BitVec.sub⟩
-
-end arithmetic
-
-end BitVec

src/Init/Data/BitVec/Folds.lean

@@ -8,8 +8,6 @@ import Init.Data.BitVec.Lemmas
 import Init.Data.Nat.Lemmas
 import Init.Data.Fin.Iterate
 
-set_option linter.missingDocs true
-
 namespace BitVec
 
 /--
@@ -41,31 +39,31 @@ theorem iunfoldr.fst_eq
 private theorem iunfoldr.eq_test
     {f : Fin w → α → α × Bool} (state : Nat → α) (value : BitVec w) (a : α)
     (init : state 0 = a)
-    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsbD i.val)) :
+    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsb i.val)) :
     iunfoldr f a = (state w, BitVec.truncate w value) := by
   apply Fin.hIterate_eq (fun i => ((state i, BitVec.truncate i value) : α × BitVec i))
   case init =>
     simp only [init, eq_nil]
   case step =>
     intro i
-    simp_all [setWidth_succ]
+    simp_all [truncate_succ]
 
-theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
+theorem iunfoldr_getLsb' {f : Fin w → α → α × Bool} (state : Nat → α)
     (ind : ∀(i : Fin w), (f i (state i.val)).fst = state (i.val+1)) :
-  (∀ i : Fin w, getLsbD (iunfoldr f (state 0)).snd i.val = (f i (state i.val)).snd)
+  (∀ i : Fin w, getLsb (iunfoldr f (state 0)).snd i.val = (f i (state i.val)).snd)
   ∧ (iunfoldr f (state 0)).fst = state w := by
   unfold iunfoldr
   simp
   apply Fin.hIterate_elim
         (fun j (p : α × BitVec j) => (hj : j ≤ w) →
-         (∀ i : Fin j,  getLsbD p.snd i.val = (f ⟨i.val, Nat.lt_of_lt_of_le i.isLt hj⟩ (state i.val)).snd)
+         (∀ i : Fin j,  getLsb p.snd i.val = (f ⟨i.val, Nat.lt_of_lt_of_le i.isLt hj⟩ (state i.val)).snd)
           ∧ p.fst = state j)
   case hj => simp
   case init =>
     intro
     apply And.intro
     · intro i
-      have := Fin.pos i
+      have := Fin.size_pos i
       contradiction
     · rfl
   case step =>
@@ -73,7 +71,7 @@ theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
     apply And.intro
     case left =>
       intro i
-      simp only [getLsbD_cons]
+      simp only [getLsb_cons]
       have hj2 : j.val ≤ w := by simp
       cases (Nat.lt_or_eq_of_le (Nat.lt_succ.mp i.isLt)) with
       | inl h3 => simp [if_neg, (Nat.ne_of_lt h3)]
@@ -90,10 +88,10 @@ theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
       rw [← ind j, ← (ih hj2).2]
 
 
-theorem iunfoldr_getLsbD {f : Fin w → α → α × Bool} (state : Nat → α) (i : Fin w)
+theorem iunfoldr_getLsb {f : Fin w → α → α × Bool} (state : Nat → α) (i : Fin w)
     (ind : ∀(i : Fin w), (f i (state i.val)).fst = state (i.val+1)) :
-  getLsbD (iunfoldr f (state 0)).snd i.val = (f i (state i.val)).snd := by
-  exact (iunfoldr_getLsbD' state ind).1 i
+  getLsb (iunfoldr f (state 0)).snd i.val = (f i (state i.val)).snd := by
+  exact (iunfoldr_getLsb' state ind).1 i
 
 /--
 Correctness theorem for `iunfoldr`.
@@ -101,14 +99,14 @@ Correctness theorem for `iunfoldr`.
 theorem iunfoldr_replace
     {f : Fin w → α → α × Bool} (state : Nat → α) (value : BitVec w) (a : α)
     (init : state 0 = a)
-    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsbD i.val)) :
+    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsb i.val)) :
     iunfoldr f a = (state w, value) := by
   simp [iunfoldr.eq_test state value a init step]
 
 theorem iunfoldr_replace_snd
   {f : Fin w → α → α × Bool} (state : Nat → α) (value : BitVec w) (a : α)
     (init : state 0 = a)
-    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsbD i.val)) :
+    (step : ∀(i : Fin w), f i (state i.val) = (state (i.val+1), value.getLsb i.val)) :
     (iunfoldr f a).snd = value := by
   simp [iunfoldr.eq_test state value a init step]
 

src/Init/Data/Bool.lean

@@ -4,15 +4,18 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: F. G. Dorais
 -/
 prelude
-import Init.NotationExtra
-
-
-namespace Bool
+import Init.BinderPredicates
 
 /-- Boolean exclusive or -/
 abbrev xor : Bool → Bool → Bool := bne
 
-@[inherit_doc] infixl:33 " ^^ " => xor
+namespace Bool
+
+/- Namespaced versions that can be used instead of prefixing `_root_` -/
+@[inherit_doc not] protected abbrev not := not
+@[inherit_doc or]  protected abbrev or  := or
+@[inherit_doc and] protected abbrev and := and
+@[inherit_doc xor] protected abbrev xor := xor
 
 instance (p : Bool → Prop) [inst : DecidablePred p] : Decidable (∀ x, p x) :=
   match inst true, inst false with
@@ -52,16 +55,10 @@ theorem eq_iff_iff {a b : Bool} : a = b ↔ (a ↔ b) := by cases b <;> simp
 theorem decide_true_eq  {b : Bool} [Decidable (true = b)]  : decide (true  = b) =  b := by cases b <;> simp
 theorem decide_false_eq {b : Bool} [Decidable (false = b)] : decide (false = b) = !b := by cases b <;> simp
 
--- These lemmas assist with confluence.
-@[simp] theorem eq_false_imp_eq_true_iff :
-    ∀ (a b : Bool), ((a = false → b = true) ↔ (b = false → a = true)) = True := by decide
-@[simp] theorem eq_true_imp_eq_false_iff :
-    ∀ (a b : Bool), ((a = true → b = false) ↔ (b = true → a = false)) = True := by decide
-
 /-! ### and -/
 
-@[simp] theorem and_self_left  : ∀ (a b : Bool), (a && (a && b)) = (a && b) := by decide
-@[simp] theorem and_self_right : ∀ (a b : Bool), ((a && b) && b) = (a && b) := by decide
+@[simp] theorem and_self_left  : ∀(a b : Bool), (a && (a && b)) = (a && b) := by decide
+@[simp] theorem and_self_right : ∀(a b : Bool), ((a && b) && b) = (a && b) := by decide
 
 @[simp] theorem not_and_self : ∀ (x : Bool), (!x && x) = false := by decide
 @[simp] theorem and_not_self : ∀ (x : Bool), (x && !x) = false := by decide
@@ -73,8 +70,8 @@ Added for confluence with `not_and_self` `and_not_self` on term
 1. `(b = true ∨ !b = true)` via `Bool.and_eq_true`
 2. `false = true` via `Bool.and_not_self`
 -/
-@[simp] theorem eq_true_and_eq_false_self : ∀ (b : Bool), (b = true ∧ b = false) ↔ False := by decide
-@[simp] theorem eq_false_and_eq_true_self : ∀ (b : Bool), (b = false ∧ b = true) ↔ False := by decide
+@[simp] theorem eq_true_and_eq_false_self : ∀(b : Bool), (b = true ∧ b = false) ↔ False := by decide
+@[simp] theorem eq_false_and_eq_true_self : ∀(b : Bool), (b = false ∧ b = true) ↔ False := by decide
 
 theorem and_comm : ∀ (x y : Bool), (x && y) = (y && x) := by decide
 instance : Std.Commutative (· && ·) := ⟨and_comm⟩
@@ -89,20 +86,15 @@ Needed for confluence of term `(a && b) ↔ a` which reduces to `(a && b) = a` v
 `Bool.coe_iff_coe` and `a → b` via `Bool.and_eq_true` and
 `and_iff_left_iff_imp`.
 -/
-@[simp] theorem and_iff_left_iff_imp  : ∀ {a b : Bool}, ((a && b) = a) ↔ (a → b) := by decide
-@[simp] theorem and_iff_right_iff_imp : ∀ {a b : Bool}, ((a && b) = b) ↔ (b → a) := by decide
-@[simp] theorem iff_self_and : ∀ {a b : Bool}, (a = (a && b)) ↔ (a → b) := by decide
-@[simp] theorem iff_and_self : ∀ {a b : Bool}, (b = (a && b)) ↔ (b → a) := by decide
-
-@[simp] theorem not_and_iff_left_iff_imp  : ∀ {a b : Bool}, ((!a && b) = a) ↔ !a ∧ !b := by decide
-@[simp] theorem and_not_iff_right_iff_imp : ∀ {a b : Bool}, ((a && !b) = b) ↔ !a ∧ !b := by decide
-@[simp] theorem iff_not_self_and : ∀ {a b : Bool}, (a = (!a && b)) ↔ !a ∧ !b := by decide
-@[simp] theorem iff_and_not_self : ∀ {a b : Bool}, (b = (a && !b)) ↔ !a ∧ !b := by decide
+@[simp] theorem and_iff_left_iff_imp  : ∀(a b : Bool), ((a && b) = a) ↔ (a → b) := by decide
+@[simp] theorem and_iff_right_iff_imp : ∀(a b : Bool), ((a && b) = b) ↔ (b → a) := by decide
+@[simp] theorem iff_self_and : ∀(a b : Bool), (a = (a && b)) ↔ (a → b) := by decide
+@[simp] theorem iff_and_self : ∀(a b : Bool), (b = (a && b)) ↔ (b → a) := by decide
 
 /-! ### or -/
 
-@[simp] theorem or_self_left  : ∀ (a b : Bool), (a || (a || b)) = (a || b) := by decide
-@[simp] theorem or_self_right : ∀ (a b : Bool), ((a || b) || b) = (a || b) := by decide
+@[simp] theorem or_self_left  : ∀(a b : Bool), (a || (a || b)) = (a || b) := by decide
+@[simp] theorem or_self_right : ∀(a b : Bool), ((a || b) || b) = (a || b) := by decide
 
 @[simp] theorem not_or_self : ∀ (x : Bool), (!x || x) = true := by decide
 @[simp] theorem or_not_self : ∀ (x : Bool), (x || !x) = true := by decide
@@ -123,15 +115,10 @@ Needed for confluence of term `(a || b) ↔ a` which reduces to `(a || b) = a` v
 `Bool.coe_iff_coe` and `a → b` via `Bool.or_eq_true` and
 `and_iff_left_iff_imp`.
 -/
-@[simp] theorem or_iff_left_iff_imp  : ∀ {a b : Bool}, ((a || b) = a) ↔ (b → a) := by decide
-@[simp] theorem or_iff_right_iff_imp : ∀ {a b : Bool}, ((a || b) = b) ↔ (a → b) := by decide
-@[simp] theorem iff_self_or : ∀ {a b : Bool}, (a = (a || b)) ↔ (b → a) := by decide
-@[simp] theorem iff_or_self : ∀ {a b : Bool}, (b = (a || b)) ↔ (a → b) := by decide
-
-@[simp] theorem not_or_iff_left_iff_imp  : ∀ {a b : Bool}, ((!a || b) = a) ↔ a ∧ b := by decide
-@[simp] theorem or_not_iff_right_iff_imp : ∀ {a b : Bool}, ((a || !b) = b) ↔ a ∧ b := by decide
-@[simp] theorem iff_not_self_or : ∀ {a b : Bool}, (a = (!a || b)) ↔ a ∧ b := by decide
-@[simp] theorem iff_or_not_self : ∀ {a b : Bool}, (b = (a || !b)) ↔ a ∧ b := by decide
+@[simp] theorem or_iff_left_iff_imp  : ∀(a b : Bool), ((a || b) = a) ↔ (b → a) := by decide
+@[simp] theorem or_iff_right_iff_imp : ∀(a b : Bool), ((a || b) = b) ↔ (a → b) := by decide
+@[simp] theorem iff_self_or : ∀(a b : Bool), (a = (a || b)) ↔ (b → a) := by decide
+@[simp] theorem iff_or_self : ∀(a b : Bool), (b = (a || b)) ↔ (a → b) := by decide
 
 theorem or_comm : ∀ (x y : Bool), (x || y) = (y || x) := by decide
 instance : Std.Commutative (· || ·) := ⟨or_comm⟩
@@ -147,8 +134,8 @@ theorem and_or_distrib_right : ∀ (x y z : Bool), ((x || y) && z) = (x && z ||
 theorem or_and_distrib_left  : ∀ (x y z : Bool), (x || y && z) = ((x || y) && (x || z)) := by decide
 theorem or_and_distrib_right : ∀ (x y z : Bool), (x && y || z) = ((x || z) && (y || z)) := by decide
 
-theorem and_xor_distrib_left  : ∀ (x y z : Bool), (x && (y ^^ z)) = ((x && y) ^^ (x && z)) := by decide
-theorem and_xor_distrib_right : ∀ (x y z : Bool), ((x ^^ y) && z) = ((x && z) ^^ (y && z)) := by decide
+theorem and_xor_distrib_left : ∀ (x y z : Bool), (x && xor y z) = xor (x && y) (x && z) := by decide
+theorem and_xor_distrib_right : ∀ (x y z : Bool), (xor x y && z) = xor (x && z) (y && z) := by decide
 
 /-- De Morgan's law for boolean and -/
 @[simp] theorem not_and : ∀ (x y : Bool), (!(x && y)) = (!x || !y) := by decide
@@ -156,10 +143,10 @@ theorem and_xor_distrib_right : ∀ (x y z : Bool), ((x ^^ y) && z) = ((x && z)
 /-- De Morgan's law for boolean or -/
 @[simp] theorem not_or : ∀ (x y : Bool), (!(x || y)) = (!x && !y) := by decide
 
-theorem and_eq_true_iff {x y : Bool} : (x && y) = true ↔ x = true ∧ y = true :=
+theorem and_eq_true_iff (x y : Bool) : (x && y) = true ↔ x = true ∧ y = true :=
   Iff.of_eq (and_eq_true x y)
 
-theorem and_eq_false_iff : ∀ {x y : Bool}, (x && y) = false ↔ x = false ∨ y = false := by decide
+theorem and_eq_false_iff : ∀ (x y : Bool), (x && y) = false ↔ x = false ∨ y = false := by decide
 
 /-
 New simp rule that replaces `Bool.and_eq_false_eq_eq_false_or_eq_false` in
@@ -174,11 +161,11 @@ Consider the term: `¬((b && c) = true)`:
 1. Further reduces to `b = false ∨ c = false` via `Bool.and_eq_false_eq_eq_false_or_eq_false`.
 2. Further reduces to `b = true → c = false` via `not_and` and `Bool.not_eq_true`.
 -/
-@[simp] theorem and_eq_false_imp : ∀ {x y : Bool}, (x && y) = false ↔ (x = true → y = false) := by decide
+@[simp] theorem and_eq_false_imp : ∀ (x y : Bool), (x && y) = false ↔ (x = true → y = false) := by decide
 
-theorem or_eq_true_iff : ∀ {x y : Bool}, (x || y) = true ↔ x = true ∨ y = true := by simp
+theorem or_eq_true_iff : ∀ (x y : Bool), (x || y) = true ↔ x = true ∨ y = true := by simp
 
-@[simp] theorem or_eq_false_iff : ∀ {x y : Bool}, (x || y) = false ↔ x = false ∧ y = false := by decide
+@[simp] theorem or_eq_false_iff : ∀ (x y : Bool), (x || y) = false ↔ x = false ∧ y = false := by decide
 
 /-! ### eq/beq/bne -/
 
@@ -215,11 +202,8 @@ instance : Std.LawfulIdentity (· != ·) false where
 @[simp] theorem not_beq_self : ∀ (x : Bool), ((!x) == x) = false := by decide
 @[simp] theorem beq_not_self : ∀ (x : Bool), (x   == !x) = false := by decide
 
-@[simp] theorem not_bne : ∀ (a b : Bool), ((!a) != b) = !(a != b) := by decide
-@[simp] theorem bne_not : ∀ (a b : Bool), (a != !b) = !(a != b) := by decide
-
-theorem not_bne_self : ∀ (x : Bool), ((!x) != x) = true := by decide
-theorem bne_not_self : ∀ (x : Bool), (x   != !x) = true := by decide
+@[simp] theorem not_bne_self : ∀ (x : Bool), ((!x) != x) = true := by decide
+@[simp] theorem bne_not_self : ∀ (x : Bool), (x   != !x) = true := by decide
 
 /-
 Added for equivalence with `Bool.not_beq_self` and needed for confluence
@@ -233,13 +217,13 @@ due to `beq_iff_eq`.
 @[simp] theorem bne_self_left  : ∀(a b : Bool), (a != (a != b)) = b := by decide
 @[simp] theorem bne_self_right : ∀(a b : Bool), ((a != b) != b) = a := by decide
 
-theorem not_bne_not : ∀ (x y : Bool), ((!x) != (!y)) = (x != y) := by simp
+@[simp] theorem not_bne_not : ∀ (x y : Bool), ((!x) != (!y)) = (x != y) := by decide
 
 @[simp] theorem bne_assoc : ∀ (x y z : Bool), ((x != y) != z) = (x != (y != z)) := by decide
 instance : Std.Associative (· != ·) := ⟨bne_assoc⟩
 
-@[simp] theorem bne_right_inj  : ∀ {x y z : Bool}, (x != y) = (x != z) ↔ y = z := by decide
-@[simp] theorem bne_left_inj : ∀ {x y z : Bool}, (x != z) = (y != z) ↔ x = y := by decide
+@[simp] theorem bne_left_inj  : ∀ (x y z : Bool), (x != y) = (x != z) ↔ y = z := by decide
+@[simp] theorem bne_right_inj : ∀ (x y z : Bool), (x != z) = (y != z) ↔ x = y := by decide
 
 theorem eq_not_of_ne : ∀ {x y : Bool}, x ≠ y → x = !y := by decide
 
@@ -251,53 +235,54 @@ theorem beq_eq_decide_eq [BEq α] [LawfulBEq α] [DecidableEq α] (a b : α) :
   · simp [ne_of_beq_false h]
   · simp [eq_of_beq h]
 
-theorem eq_not : ∀ {a b : Bool}, (a = (!b)) ↔ (a ≠ b) := by decide
-theorem not_eq : ∀ {a b : Bool}, ((!a) = b) ↔ (a ≠ b) := by decide
+@[simp] theorem not_eq_not : ∀ {a b : Bool}, ¬a = !b ↔ a = b := by decide
 
-@[simp] theorem coe_iff_coe : ∀{a b : Bool}, (a ↔ b) ↔ a = b := by decide
+@[simp] theorem not_not_eq : ∀ {a b : Bool}, ¬(!a) = b ↔ a = b := by decide
 
-@[simp] theorem coe_true_iff_false  : ∀{a b : Bool}, (a ↔ b = false) ↔ a = (!b) := by decide
-@[simp] theorem coe_false_iff_true  : ∀{a b : Bool}, (a = false ↔ b) ↔ (!a) = b := by decide
-@[simp] theorem coe_false_iff_false : ∀{a b : Bool}, (a = false ↔ b = false) ↔ (!a) = (!b) := by decide
+@[simp] theorem coe_iff_coe : ∀(a b : Bool), (a ↔ b) ↔ a = b := by decide
+
+@[simp] theorem coe_true_iff_false  : ∀(a b : Bool), (a ↔ b = false) ↔ a = (!b) := by decide
+@[simp] theorem coe_false_iff_true  : ∀(a b : Bool), (a = false ↔ b) ↔ (!a) = b := by decide
+@[simp] theorem coe_false_iff_false : ∀(a b : Bool), (a = false ↔ b = false) ↔ (!a) = (!b) := by decide
 
 /-! ### beq properties -/
 
 theorem beq_comm {α} [BEq α] [LawfulBEq α] {a b : α} : (a == b) = (b == a) :=
-  Bool.coe_iff_coe.mp (by simp [@eq_comm α])
+  (Bool.coe_iff_coe (a == b) (b == a)).mp (by simp [@eq_comm α])
 
 /-! ### xor -/
 
-theorem false_xor : ∀ (x : Bool), (false ^^ x) = x := false_bne
+theorem false_xor : ∀ (x : Bool), xor false x = x := false_bne
 
-theorem xor_false : ∀ (x : Bool), (x ^^ false) = x := bne_false
+theorem xor_false : ∀ (x : Bool), xor x false = x := bne_false
 
-theorem true_xor : ∀ (x : Bool), (true ^^ x) = !x := true_bne
+theorem true_xor : ∀ (x : Bool), xor true x = !x := true_bne
 
-theorem xor_true : ∀ (x : Bool), (x ^^ true) = !x := bne_true
+theorem xor_true : ∀ (x : Bool), xor x true = !x := bne_true
 
-theorem not_xor_self : ∀ (x : Bool), (!x ^^ x) = true := not_bne_self
+theorem not_xor_self : ∀ (x : Bool), xor (!x) x = true := not_bne_self
 
-theorem xor_not_self : ∀ (x : Bool), (x ^^ !x) = true := bne_not_self
+theorem xor_not_self : ∀ (x : Bool), xor x (!x) = true := bne_not_self
 
-theorem not_xor : ∀ (x y : Bool), (!x ^^ y) = !(x ^^ y) := by decide
+theorem not_xor : ∀ (x y : Bool), xor (!x) y = !(xor x y) := by decide
 
-theorem xor_not : ∀ (x y : Bool), (x ^^ !y) = !(x ^^ y) := by decide
+theorem xor_not : ∀ (x y : Bool), xor x (!y) = !(xor x y) := by decide
 
-theorem not_xor_not : ∀ (x y : Bool), (!x ^^ !y) = (x ^^ y) := not_bne_not
+theorem not_xor_not : ∀ (x y : Bool), xor (!x) (!y) = (xor x y) := not_bne_not
 
-theorem xor_self : ∀ (x : Bool), (x ^^ x) = false := by decide
+theorem xor_self : ∀ (x : Bool), xor x x = false := by decide
 
-theorem xor_comm : ∀ (x y : Bool), (x ^^ y) = (y ^^ x) := by decide
+theorem xor_comm : ∀ (x y : Bool), xor x y = xor y x := by decide
 
-theorem xor_left_comm : ∀ (x y z : Bool), (x ^^ (y ^^ z)) = (y ^^ (x ^^ z)) := by decide
+theorem xor_left_comm : ∀ (x y z : Bool), xor x (xor y z) = xor y (xor x z) := by decide
 
-theorem xor_right_comm : ∀ (x y z : Bool), ((x ^^ y) ^^ z) = ((x ^^ z) ^^ y) := by decide
+theorem xor_right_comm : ∀ (x y z : Bool), xor (xor x y) z = xor (xor x z) y := by decide
 
-theorem xor_assoc : ∀ (x y z : Bool), ((x ^^ y) ^^ z) = (x ^^ (y ^^ z)) := bne_assoc
+theorem xor_assoc : ∀ (x y z : Bool), xor (xor x y) z = xor x (xor y z) := bne_assoc
 
-theorem xor_right_inj : ∀ {x y z : Bool}, (x ^^ y) = (x ^^ z) ↔ y = z := bne_right_inj
+theorem xor_left_inj : ∀ (x y z : Bool), xor x y = xor x z ↔ y = z := bne_left_inj
 
-theorem xor_left_inj : ∀ {x y z : Bool}, (x ^^ z) = (y ^^ z) ↔ x = y := bne_left_inj
+theorem xor_right_inj : ∀ (x y z : Bool), xor x z = xor y z ↔ x = y := bne_right_inj
 
 /-! ### le/lt -/
 
@@ -368,20 +353,22 @@ theorem and_or_inj_left_iff :
 /-- convert a `Bool` to a `Nat`, `false -> 0`, `true -> 1` -/
 def toNat (b : Bool) : Nat := cond b 1 0
 
-@[simp, bv_toNat] theorem toNat_false : false.toNat = 0 := rfl
+@[simp] theorem toNat_false : false.toNat = 0 := rfl
 
-@[simp, bv_toNat] theorem toNat_true : true.toNat = 1 := rfl
+@[simp] theorem toNat_true : true.toNat = 1 := rfl
 
 theorem toNat_le (c : Bool) : c.toNat ≤ 1 := by
   cases c <;> trivial
 
-@[bv_toNat]
+@[deprecated toNat_le (since := "2024-02-23")]
+abbrev toNat_le_one := toNat_le
+
 theorem toNat_lt (b : Bool) : b.toNat < 2 :=
   Nat.lt_succ_of_le (toNat_le _)
 
-@[simp] theorem toNat_eq_zero {b : Bool} : b.toNat = 0 ↔ b = false := by
+@[simp] theorem toNat_eq_zero (b : Bool) : b.toNat = 0 ↔ b = false := by
   cases b <;> simp
-@[simp] theorem toNat_eq_one  {b : Bool} : b.toNat = 1 ↔ b = true := by
+@[simp] theorem toNat_eq_one  (b : Bool) : b.toNat = 1 ↔ b = true := by
   cases b <;> simp
 
 /-! ### ite -/
@@ -406,13 +393,6 @@ theorem toNat_lt (b : Bool) : b.toNat < 2 :=
     (ite p t f = false) = ite p (t = false) (f = false) := by
   cases h with | _ p => simp [p]
 
-@[simp] theorem ite_eq_false : (if b = false then p else q) ↔ if b then q else p := by
-  cases b <;> simp
-
-@[simp] theorem ite_eq_true_else_eq_false {q : Prop} :
-    (if b = true then q else b = false) ↔ (b = true → q) := by
-  cases b <;> simp
-
 /-
 `not_ite_eq_true_eq_true` and related theorems below are added for
 non-confluence.  A motivating example is
@@ -427,57 +407,37 @@ lemmas.
 -/
 
 @[simp]
-theorem not_ite_eq_true_eq_true {p : Prop} [h : Decidable p] {b c : Bool} :
+theorem not_ite_eq_true_eq_true (p : Prop) [h : Decidable p] (b c : Bool) :
   ¬(ite p (b = true) (c = true)) ↔ (ite p (b = false) (c = false)) := by
   cases h with | _ p => simp [p]
 
 @[simp]
-theorem not_ite_eq_false_eq_false {p : Prop} [h : Decidable p] {b c : Bool} :
+theorem not_ite_eq_false_eq_false (p : Prop) [h : Decidable p] (b c : Bool) :
   ¬(ite p (b = false) (c = false)) ↔ (ite p (b = true) (c = true)) := by
   cases h with | _ p => simp [p]
 
 @[simp]
-theorem not_ite_eq_true_eq_false {p : Prop} [h : Decidable p] {b c : Bool} :
+theorem not_ite_eq_true_eq_false (p : Prop) [h : Decidable p] (b c : Bool) :
   ¬(ite p (b = true) (c = false)) ↔ (ite p (b = false) (c = true)) := by
   cases h with | _ p => simp [p]
 
 @[simp]
-theorem not_ite_eq_false_eq_true {p : Prop} [h : Decidable p] {b c : Bool} :
+theorem not_ite_eq_false_eq_true (p : Prop) [h : Decidable p] (b c : Bool) :
   ¬(ite p (b = false) (c = true)) ↔ (ite p (b = true) (c = false)) := by
   cases h with | _ p => simp [p]
 
 /-
-It would be nice to have this for confluence between `if_true_left` and `ite_false_same` on
-`if b = true then True else b = true`.
-However the discrimination tree key is just `→`, so this is tried too often.
+Added for confluence between `if_true_left` and `ite_false_same` on
+`if b = true then True else b = true`
 -/
-theorem eq_false_imp_eq_true : ∀ {b : Bool}, (b = false → b = true) ↔ (b = true) := by decide
+@[simp] theorem eq_false_imp_eq_true : ∀(b:Bool), (b = false → b = true) ↔ (b = true) := by decide
 
 /-
-It would be nice to have this for confluence between `if_true_left` and `ite_false_same` on
-`if b = false then True else b = false`.
-However the discrimination tree key is just `→`, so this is tried too often.
+Added for confluence between `if_true_left` and `ite_false_same` on
+`if b = false then True else b = false`
 -/
-theorem eq_true_imp_eq_false : ∀ {b : Bool}, (b = true → b = false) ↔ (b = false) := by decide
+@[simp] theorem eq_true_imp_eq_false : ∀(b:Bool), (b = true → b = false) ↔ (b = false) := by decide
 
-/-! ### forall -/
-
-theorem forall_bool' {p : Bool → Prop} (b : Bool) : (∀ x, p x) ↔ p b ∧ p !b :=
-  ⟨fun h ↦ ⟨h _, h _⟩, fun ⟨h₁, h₂⟩ x ↦ by cases b <;> cases x <;> assumption⟩
-
-@[simp]
-theorem forall_bool {p : Bool → Prop} : (∀ b, p b) ↔ p false ∧ p true :=
-  forall_bool' false
-
-/-! ### exists -/
-
-theorem exists_bool' {p : Bool → Prop} (b : Bool) : (∃ x, p x) ↔ p b ∨ p !b :=
-  ⟨fun ⟨x, hx⟩ ↦ by cases x <;> cases b <;> first | exact .inl ‹_› | exact .inr ‹_›,
-    fun h ↦ by cases h <;> exact ⟨_, ‹_›⟩⟩
-
-@[simp]
-theorem exists_bool {p : Bool → Prop} : (∃ b, p b) ↔ p false ∨ p true :=
-  exists_bool' false
 
 /-! ### cond -/
 
@@ -491,11 +451,6 @@ theorem cond_eq_if : (bif b then x else y) = (if b then x else y) := cond_eq_ite
 
 @[simp] theorem cond_self (c : Bool) (t : α) : cond c t t = t := by cases c <;> rfl
 
-/-- If the return values are propositions, there is no harm in simplifying a `bif` to an `if`. -/
-@[simp] theorem cond_prop {b : Bool} {p q : Prop} :
-    (bif b then p else q) ↔ if b then p else q := by
-  cases b <;> simp
-
 /-
 This is a simp rule in Mathlib, but results in non-confluence that is difficult
 to fix as decide distributes over propositions. As an example, observe that
@@ -513,11 +468,11 @@ theorem cond_decide {α} (p : Prop) [Decidable p] (t e : α) :
     cond (decide p) t e = if p then t else e := by
   simp [cond_eq_ite]
 
-@[simp] theorem cond_eq_ite_iff {a : Bool} {p : Prop} [h : Decidable p] {x y u v : α} :
+@[simp] theorem cond_eq_ite_iff (a : Bool) (p : Prop) [h : Decidable p] (x y u v : α) :
   (cond a x y = ite p u v) ↔ ite a x y = ite p u v := by
   simp [Bool.cond_eq_ite]
 
-@[simp] theorem ite_eq_cond_iff {p : Prop} {a : Bool} [h : Decidable p] {x y u v : α} :
+@[simp] theorem ite_eq_cond_iff (p : Prop) [h : Decidable p] (a : Bool) (x y u v : α) :
   (ite p x y = cond a u v) ↔ ite p x y = ite a u v := by
   simp [Bool.cond_eq_ite]
 
@@ -536,10 +491,6 @@ protected theorem cond_false {α : Type u} {a b : α} : cond false a b = b := co
 @[simp] theorem cond_true_right  : ∀(c t : Bool), cond c t true  = (!c || t) := by decide
 @[simp] theorem cond_false_right : ∀(c t : Bool), cond c t false = ( c && t) := by decide
 
--- These restore confluence between the above lemmas and `cond_not`.
-@[simp] theorem cond_true_not_same  : ∀ (c b : Bool), cond c (!c) b = (!c && b) := by decide
-@[simp] theorem cond_false_not_same : ∀ (c b : Bool), cond c b (!c) = (!c || b) := by decide
-
 @[simp] theorem cond_true_same  : ∀(c b : Bool), cond c c b = (c || b) := by decide
 @[simp] theorem cond_false_same : ∀(c b : Bool), cond c b c = (c && b) := by decide
 
@@ -553,7 +504,7 @@ theorem apply_cond (f : α → β) {b : Bool} {a a' : α} :
     f (bif b then a else a') = bif b then f a else f a' := by
   cases b <;> simp
 
-/-! # decidability -/
+/-# decidability -/
 
 protected theorem decide_coe (b : Bool) [Decidable (b = true)] : decide (b = true) = b := decide_eq_true
 
@@ -569,24 +520,9 @@ protected theorem decide_coe (b : Bool) [Decidable (b = true)] : decide (b = tru
     decide (p ↔ q) = (decide p == decide q) := by
   cases dp with | _ p => simp [p]
 
-@[boolToPropSimps]
-theorem and_eq_decide (p q : Prop) [dpq : Decidable (p ∧ q)] [dp : Decidable p] [dq : Decidable q] :
-    (p && q) = decide (p ∧ q) := by
-  cases dp with | _ p => simp [p]
-
-@[boolToPropSimps]
-theorem or_eq_decide (p q : Prop) [dpq : Decidable (p ∨ q)] [dp : Decidable p] [dq : Decidable q] :
-    (p || q) = decide (p ∨ q) := by
-  cases dp with | _ p => simp [p]
-
-@[boolToPropSimps]
-theorem decide_beq_decide (p q : Prop) [dpq : Decidable (p ↔ q)] [dp : Decidable p] [dq : Decidable q] :
-    (decide p == decide q) = decide (p ↔ q) := by
-  cases dp with | _ p => simp [p]
-
 end Bool
 
-export Bool (cond_eq_if xor and or not)
+export Bool (cond_eq_if)
 
 /-! ### decide -/
 
@@ -595,19 +531,3 @@ export Bool (cond_eq_if xor and or not)
 
 @[simp] theorem true_eq_decide_iff {p : Prop} [h : Decidable p] : true = decide p ↔ p := by
   cases h with | _ q => simp [q]
-
-/-! ### coercions -/
-
-/--
-This should not be turned on globally as an instance because it degrades performance in Mathlib,
-but may be used locally.
--/
-def boolPredToPred : Coe (α → Bool) (α  → Prop) where
-  coe r := fun a => Eq (r a) true
-
-/--
-This should not be turned on globally as an instance because it degrades performance in Mathlib,
-but may be used locally.
--/
-def boolRelToRel : Coe (α → α → Bool) (α → α → Prop) where
-  coe r := fun a b => Eq (r a b) true

src/Init/Data/ByteArray/Basic.lean

@@ -37,12 +37,8 @@ def push : ByteArray → UInt8 → ByteArray
 def size : (@& ByteArray) → Nat
   | ⟨bs⟩ => bs.size
 
-@[extern "lean_sarray_size", simp]
-def usize (a : @& ByteArray) : USize :=
-  a.size.toUSize
-
 @[extern "lean_byte_array_uget"]
-def uget : (a : @& ByteArray) → (i : USize) → (h : i.toNat < a.size := by get_elem_tactic) → UInt8
+def uget : (a : @& ByteArray) → (i : USize) → i.toNat < a.size → UInt8
   | ⟨bs⟩, i, h => bs[i]
 
 @[extern "lean_byte_array_get"]
@@ -50,11 +46,11 @@ def get! : (@& ByteArray) → (@& Nat) → UInt8
   | ⟨bs⟩, i => bs.get! i
 
 @[extern "lean_byte_array_fget"]
-def get : (a : @& ByteArray) → (i : @& Nat) → (h : i < a.size := by get_elem_tactic) → UInt8
-  | ⟨bs⟩, i, _ => bs[i]
+def get : (a : @& ByteArray) → (@& Fin a.size) → UInt8
+  | ⟨bs⟩, i => bs.get i
 
 instance : GetElem ByteArray Nat UInt8 fun xs i => i < xs.size where
-  getElem xs i h := xs.get i
+  getElem xs i h := xs.get ⟨i, h⟩
 
 instance : GetElem ByteArray USize UInt8 fun xs i => i.val < xs.size where
   getElem xs i h := xs.uget i h
@@ -64,11 +60,11 @@ def set! : ByteArray → (@& Nat) → UInt8 → ByteArray
   | ⟨bs⟩, i, b => ⟨bs.set! i b⟩
 
 @[extern "lean_byte_array_fset"]
-def set : (a : ByteArray) → (i : @& Nat) → UInt8 → (h : i < a.size := by get_elem_tactic) → ByteArray
-  | ⟨bs⟩, i, b, h => ⟨bs.set i b h⟩
+def set : (a : ByteArray) → (@& Fin a.size) → UInt8 → ByteArray
+  | ⟨bs⟩, i, b => ⟨bs.set i b⟩
 
 @[extern "lean_byte_array_uset"]
-def uset : (a : ByteArray) → (i : USize) → UInt8 → (h : i.toNat < a.size := by get_elem_tactic) → ByteArray
+def uset : (a : ByteArray) → (i : USize) → UInt8 → i.toNat < a.size → ByteArray
   | ⟨bs⟩, i, v, h => ⟨bs.uset i v h⟩
 
 @[extern "lean_byte_array_hash"]
@@ -123,7 +119,7 @@ def toList (bs : ByteArray) : List UInt8 :=
   TODO: avoid code duplication in the future after we improve the compiler.
 -/
 @[inline] unsafe def forInUnsafe {β : Type v} {m : Type v → Type w} [Monad m] (as : ByteArray) (b : β) (f : UInt8 → β → m (ForInStep β)) : m β :=
-  let sz := as.usize
+  let sz := USize.ofNat as.size
   let rec @[specialize] loop (i : USize) (b : β) : m β := do
     if i < sz then
       let a := as.uget i lcProof
@@ -144,7 +140,7 @@ protected def forIn {β : Type v} {m : Type v → Type w} [Monad m] (as : ByteAr
       have h' : i < as.size            := Nat.lt_of_lt_of_le (Nat.lt_succ_self i) h
       have : as.size - 1 < as.size     := Nat.sub_lt (Nat.zero_lt_of_lt h') (by decide)
       have : as.size - 1 - i < as.size := Nat.lt_of_le_of_lt (Nat.sub_le (as.size - 1) i) this
-      match (← f as[as.size - 1 - i] b) with
+      match (← f (as.get ⟨as.size - 1 - i, this⟩) b) with
       | ForInStep.done b  => pure b
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
@@ -178,7 +174,7 @@ def foldlM {β : Type v} {m : Type v → Type w} [Monad m] (f : β → UInt8 →
         match i with
         | 0    => pure b
         | i'+1 =>
-          loop i' (j+1) (← f b as[j])
+          loop i' (j+1) (← f b (as.get ⟨j, Nat.lt_of_lt_of_le hlt h⟩))
       else
         pure b
     loop (stop - start) start init
@@ -191,137 +187,6 @@ def foldlM {β : Type v} {m : Type v → Type w} [Monad m] (f : β → UInt8 →
 def foldl {β : Type v} (f : β → UInt8 → β) (init : β) (as : ByteArray) (start := 0) (stop := as.size) : β :=
   Id.run <| as.foldlM f init start stop
 
-/-- Iterator over the bytes (`UInt8`) of a `ByteArray`.
-
-Typically created by `arr.iter`, where `arr` is a `ByteArray`.
-
-An iterator is *valid* if the position `i` is *valid* for the array `arr`, meaning `0 ≤ i ≤ arr.size`
-
-Most operations on iterators return arbitrary values if the iterator is not valid. The functions in
-the `ByteArray.Iterator` API should rule out the creation of invalid iterators, with two exceptions:
-
-- `Iterator.next iter` is invalid if `iter` is already at the end of the array (`iter.atEnd` is
-  `true`)
-- `Iterator.forward iter n`/`Iterator.nextn iter n` is invalid if `n` is strictly greater than the
-  number of remaining bytes.
--/
-structure Iterator where
-  /-- The array the iterator is for. -/
-  array : ByteArray
-  /-- The current position.
-
-  This position is not necessarily valid for the array, for instance if one keeps calling
-  `Iterator.next` when `Iterator.atEnd` is true. If the position is not valid, then the
-  current byte is `(default : UInt8)`. -/
-  idx : Nat
-  deriving Inhabited
-
-/-- Creates an iterator at the beginning of an array. -/
-def mkIterator (arr : ByteArray) : Iterator :=
-  ⟨arr, 0⟩
-
-@[inherit_doc mkIterator]
-abbrev iter := mkIterator
-
-/-- The size of an array iterator is the number of bytes remaining. -/
-instance : SizeOf Iterator where
-  sizeOf i := i.array.size - i.idx
-
-theorem Iterator.sizeOf_eq (i : Iterator) : sizeOf i = i.array.size - i.idx :=
-  rfl
-
-namespace Iterator
-
-/-- Number of bytes remaining in the iterator. -/
-def remainingBytes : Iterator → Nat
-  | ⟨arr, i⟩ => arr.size - i
-
-@[inherit_doc Iterator.idx]
-def pos := Iterator.idx
-
-/-- The byte at the current position.
-
-On an invalid position, returns `(default : UInt8)`. -/
-@[inline]
-def curr : Iterator → UInt8
-  | ⟨arr, i⟩ =>
-    if h : i < arr.size then
-      arr[i]'h
-    else
-      default
-
-/-- Moves the iterator's position forward by one byte, unconditionally.
-
-It is only valid to call this function if the iterator is not at the end of the array, *i.e.*
-`Iterator.atEnd` is `false`; otherwise, the resulting iterator will be invalid. -/
-@[inline]
-def next : Iterator → Iterator
-  | ⟨arr, i⟩ => ⟨arr, i + 1⟩
-
-/-- Decreases the iterator's position.
-
-If the position is zero, this function is the identity. -/
-@[inline]
-def prev : Iterator → Iterator
-  | ⟨arr, i⟩ => ⟨arr, i - 1⟩
-
-/-- True if the iterator is past the array's last byte. -/
-@[inline]
-def atEnd : Iterator → Bool
-  | ⟨arr, i⟩ => i ≥ arr.size
-
-/-- True if the iterator is not past the array's last byte. -/
-@[inline]
-def hasNext : Iterator → Bool
-  | ⟨arr, i⟩ => i < arr.size
-
-/-- The byte at the current position. --/
-@[inline]
-def curr' (it : Iterator) (h : it.hasNext) : UInt8 :=
-  match it with
-  | ⟨arr, i⟩ =>
-    have : i < arr.size := by
-      simp only [hasNext, decide_eq_true_eq] at h
-      assumption
-    arr[i]
-
-/-- Moves the iterator's position forward by one byte. --/
-@[inline]
-def next' (it : Iterator) (_h : it.hasNext) : Iterator :=
-  match it with
-  | ⟨arr, i⟩ => ⟨arr, i + 1⟩
-
-/-- True if the position is not zero. -/
-@[inline]
-def hasPrev : Iterator → Bool
-  | ⟨_, i⟩ => i > 0
-
-/-- Moves the iterator's position to the end of the array.
-
-Note that `i.toEnd.atEnd` is always `true`. -/
-@[inline]
-def toEnd : Iterator → Iterator
-  | ⟨arr, _⟩ => ⟨arr, arr.size⟩
-
-/-- Moves the iterator's position several bytes forward.
-
-The resulting iterator is only valid if the number of bytes to skip is less than or equal to
-the number of bytes left in the iterator. -/
-@[inline]
-def forward : Iterator → Nat → Iterator
-  | ⟨arr, i⟩, f => ⟨arr, i + f⟩
-
-@[inherit_doc forward, inline]
-def nextn : Iterator → Nat → Iterator := forward
-
-/-- Moves the iterator's position several bytes back.
-
-If asked to go back more bytes than available, stops at the beginning of the array. -/
-@[inline]
-def prevn : Iterator → Nat → Iterator
-  | ⟨arr, i⟩, f => ⟨arr, i - f⟩
-
-end Iterator
 end ByteArray
 
 def List.toByteArray (bs : List UInt8) : ByteArray :=

src/Init/Data/Char/Basic.lean

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 -/
 prelude
-import Init.Data.UInt.BasicAux
+import Init.Data.UInt.Basic
 
 /-- Determines if the given integer is a valid [Unicode scalar value](https://www.unicode.org/glossary/#unicode_scalar_value).
 
@@ -42,10 +42,8 @@ theorem isValidUInt32 (n : Nat) (h : isValidCharNat n) : n < UInt32.size := by
 
 theorem isValidChar_of_isValidCharNat (n : Nat) (h : isValidCharNat n) : isValidChar (UInt32.ofNat' n (isValidUInt32 n h)) :=
   match h with
-  | Or.inl h =>
-    Or.inl (UInt32.ofNat'_lt_of_lt _ (by decide) h)
-  | Or.inr ⟨h₁, h₂⟩ =>
-    Or.inr ⟨UInt32.lt_ofNat'_of_lt _ (by decide) h₁, UInt32.ofNat'_lt_of_lt _ (by decide) h₂⟩
+  | Or.inl h        => Or.inl h
+  | Or.inr ⟨h₁, h₂⟩ => Or.inr ⟨h₁, h₂⟩
 
 theorem isValidChar_zero : isValidChar 0 :=
   Or.inl (by decide)
@@ -59,33 +57,33 @@ theorem isValidChar_zero : isValidChar 0 :=
   c.val.toUInt8
 
 /-- The numbers from 0 to 256 are all valid UTF-8 characters, so we can embed one in the other. -/
-def ofUInt8 (n : UInt8) : Char := ⟨n.toUInt32, .inl (Nat.lt_trans n.toBitVec.isLt (by decide))⟩
+def ofUInt8 (n : UInt8) : Char := ⟨n.toUInt32, .inl (Nat.lt_trans n.1.2 (by decide))⟩
 
 instance : Inhabited Char where
   default := 'A'
 
 /-- Is the character a space (U+0020) a tab (U+0009), a carriage return (U+000D) or a newline (U+000A)? -/
-@[inline] def isWhitespace (c : Char) : Bool :=
+def isWhitespace (c : Char) : Bool :=
   c = ' ' || c = '\t' || c = '\r' || c = '\n'
 
 /-- Is the character in `ABCDEFGHIJKLMNOPQRSTUVWXYZ`? -/
-@[inline] def isUpper (c : Char) : Bool :=
+def isUpper (c : Char) : Bool :=
   c.val ≥ 65 && c.val ≤ 90
 
 /-- Is the character in `abcdefghijklmnopqrstuvwxyz`? -/
-@[inline] def isLower (c : Char) : Bool :=
+def isLower (c : Char) : Bool :=
   c.val ≥ 97 && c.val ≤ 122
 
 /-- Is the character in `ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`? -/
-@[inline] def isAlpha (c : Char) : Bool :=
+def isAlpha (c : Char) : Bool :=
   c.isUpper || c.isLower
 
 /-- Is the character in `0123456789`? -/
-@[inline] def isDigit (c : Char) : Bool :=
+def isDigit (c : Char) : Bool :=
   c.val ≥ 48 && c.val ≤ 57
 
 /-- Is the character in `ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789`? -/
-@[inline] def isAlphanum (c : Char) : Bool :=
+def isAlphanum (c : Char) : Bool :=
   c.isAlpha || c.isDigit
 
 /-- Convert an upper case character to its lower case character.

src/Init/Data/Fin/Basic.lean

@@ -14,7 +14,7 @@ instance coeToNat : CoeOut (Fin n) Nat :=
   ⟨fun v => v.val⟩
 
 /--
-From the empty type `Fin 0`, any desired result `α` can be derived. This is similar to `Empty.elim`.
+From the empty type `Fin 0`, any desired result `α` can be derived. This is simlar to `Empty.elim`.
 -/
 def elim0.{u} {α : Sort u} : Fin 0 → α
   | ⟨_, h⟩ => absurd h (not_lt_zero _)
@@ -31,7 +31,7 @@ This differs from addition, which wraps around:
 (2 : Fin 3) + 1 = (0 : Fin 3)
 ```
 -/
-def succ : Fin n → Fin (n + 1)
+def succ : Fin n → Fin n.succ
   | ⟨i, h⟩ => ⟨i+1, Nat.succ_lt_succ h⟩
 
 variable {n : Nat}
@@ -39,20 +39,16 @@ variable {n : Nat}
 /--
 Returns `a` modulo `n + 1` as a `Fin n.succ`.
 -/
-protected def ofNat {n : Nat} (a : Nat) : Fin (n + 1) :=
+protected def ofNat {n : Nat} (a : Nat) : Fin n.succ :=
   ⟨a % (n+1), Nat.mod_lt _ (Nat.zero_lt_succ _)⟩
 
 /--
 Returns `a` modulo `n` as a `Fin n`.
 
-The assumption `NeZero n` ensures that `Fin n` is nonempty.
+The assumption `n > 0` ensures that `Fin n` is nonempty.
 -/
-protected def ofNat' (n : Nat) [NeZero n] (a : Nat) : Fin n :=
-  ⟨a % n, Nat.mod_lt _ (pos_of_neZero n)⟩
-
--- We intend to deprecate `Fin.ofNat` in favor of `Fin.ofNat'` (and later rename).
--- This is waiting on https://github.com/leanprover/lean4/pull/5323
--- attribute [deprecated Fin.ofNat' (since := "2024-09-16")] Fin.ofNat
+protected def ofNat' {n : Nat} (a : Nat) (h : n > 0) : Fin n :=
+  ⟨a % n, Nat.mod_lt _ h⟩
 
 private theorem mlt {b : Nat} : {a : Nat} → a < n → b % n < n
   | 0,   h => Nat.mod_lt _ h
@@ -145,17 +141,14 @@ instance : ShiftLeft (Fin n) where
 instance : ShiftRight (Fin n) where
   shiftRight := Fin.shiftRight
 
-instance instOfNat {n : Nat} [NeZero n] {i : Nat} : OfNat (Fin n) i where
-  ofNat := Fin.ofNat' n i
+instance instOfNat : OfNat (Fin (no_index (n+1))) i where
+  ofNat := Fin.ofNat i
 
-instance instInhabited {n : Nat} [NeZero n] : Inhabited (Fin n) where
+instance : Inhabited (Fin (no_index (n+1))) where
   default := 0
 
 @[simp] theorem zero_eta : (⟨0, Nat.zero_lt_succ _⟩ : Fin (n + 1)) = 0 := rfl
 
-theorem ne_of_val_ne {i j : Fin n} (h : val i ≠ val j) : i ≠ j :=
-  fun h' => absurd (val_eq_of_eq h') h
-
 theorem val_ne_of_ne {i j : Fin n} (h : i ≠ j) : val i ≠ val j :=
   fun h' => absurd (eq_of_val_eq h') h
 
@@ -165,7 +158,6 @@ theorem modn_lt : ∀ {m : Nat} (i : Fin n), m > 0 → (modn i m).val < m
 theorem val_lt_of_le (i : Fin b) (h : b ≤ n) : i.val < n :=
   Nat.lt_of_lt_of_le i.isLt h
 
-/-- If you actually have an element of `Fin n`, then the `n` is always positive -/
 protected theorem pos (i : Fin n) : 0 < n :=
   Nat.lt_of_le_of_lt (Nat.zero_le _) i.2
 

src/Init/Data/Fin/Fold.lean

@@ -5,8 +5,6 @@ Authors: François G. Dorais
 -/
 prelude
 import Init.Data.Nat.Linear
-import Init.Control.Lawful.Basic
-import Init.Data.Fin.Lemmas
 
 namespace Fin
 
@@ -25,195 +23,4 @@ namespace Fin
   | ⟨0, _⟩, x => x
   | ⟨i+1, h⟩, x => loop ⟨i, Nat.le_of_lt h⟩ (f ⟨i, h⟩ x)
 
-/--
-Folds a monadic function over `Fin n` from left to right:
-```
-Fin.foldlM n f x₀ = do
-  let x₁ ← f x₀ 0
-  let x₂ ← f x₁ 1
-  ...
-  let xₙ ← f xₙ₋₁ (n-1)
-  pure xₙ
-```
--/
-@[inline] def foldlM [Monad m] (n) (f : α → Fin n → m α) (init : α) : m α := loop init 0 where
-  /--
-  Inner loop for `Fin.foldlM`.
-  ```
-  Fin.foldlM.loop n f xᵢ i = do
-    let xᵢ₊₁ ← f xᵢ i
-    ...
-    let xₙ ← f xₙ₋₁ (n-1)
-    pure xₙ
-  ```
-  -/
-  loop (x : α) (i : Nat) : m α := do
-    if h : i < n then f x ⟨i, h⟩ >>= (loop · (i+1)) else pure x
-  termination_by n - i
-  decreasing_by decreasing_trivial_pre_omega
-
-/--
-Folds a monadic function over `Fin n` from right to left:
-```
-Fin.foldrM n f xₙ = do
-  let xₙ₋₁ ← f (n-1) xₙ
-  let xₙ₋₂ ← f (n-2) xₙ₋₁
-  ...
-  let x₀ ← f 0 x₁
-  pure x₀
-```
--/
-@[inline] def foldrM [Monad m] (n) (f : Fin n → α → m α) (init : α) : m α :=
-  loop ⟨n, Nat.le_refl n⟩ init where
-  /--
-  Inner loop for `Fin.foldrM`.
-  ```
-  Fin.foldrM.loop n f i xᵢ = do
-    let xᵢ₋₁ ← f (i-1) xᵢ
-    ...
-    let x₁ ← f 1 x₂
-    let x₀ ← f 0 x₁
-    pure x₀
-  ```
-  -/
-  loop : {i // i ≤ n} → α → m α
-  | ⟨0, _⟩, x => pure x
-  | ⟨i+1, h⟩, x => f ⟨i, h⟩ x >>= loop ⟨i, Nat.le_of_lt h⟩
-
-/-! ### foldlM -/
-
-theorem foldlM_loop_lt [Monad m] (f : α → Fin n → m α) (x) (h : i < n) :
-    foldlM.loop n f x i = f x ⟨i, h⟩ >>= (foldlM.loop n f . (i+1)) := by
-  rw [foldlM.loop, dif_pos h]
-
-theorem foldlM_loop_eq [Monad m] (f : α → Fin n → m α) (x) : foldlM.loop n f x n = pure x := by
-  rw [foldlM.loop, dif_neg (Nat.lt_irrefl _)]
-
-theorem foldlM_loop [Monad m] (f : α → Fin (n+1) → m α) (x) (h : i < n+1) :
-    foldlM.loop (n+1) f x i = f x ⟨i, h⟩ >>= (foldlM.loop n (fun x j => f x j.succ) . i) := by
-  if h' : i < n then
-    rw [foldlM_loop_lt _ _ h]
-    congr; funext
-    rw [foldlM_loop_lt _ _ h', foldlM_loop]; rfl
-  else
-    cases Nat.le_antisymm (Nat.le_of_lt_succ h) (Nat.not_lt.1 h')
-    rw [foldlM_loop_lt]
-    congr; funext
-    rw [foldlM_loop_eq, foldlM_loop_eq]
-termination_by n - i
-
-@[simp] theorem foldlM_zero [Monad m] (f : α → Fin 0 → m α) (x) : foldlM 0 f x = pure x :=
-  foldlM_loop_eq ..
-
-theorem foldlM_succ [Monad m] (f : α → Fin (n+1) → m α) (x) :
-    foldlM (n+1) f x = f x 0 >>= foldlM n (fun x j => f x j.succ) := foldlM_loop ..
-
-/-! ### foldrM -/
-
-theorem foldrM_loop_zero [Monad m] (f : Fin n → α → m α) (x) :
-    foldrM.loop n f ⟨0, Nat.zero_le _⟩ x = pure x := by
-  rw [foldrM.loop]
-
-theorem foldrM_loop_succ [Monad m] (f : Fin n → α → m α) (x) (h : i < n) :
-    foldrM.loop n f ⟨i+1, h⟩ x = f ⟨i, h⟩ x >>= foldrM.loop n f ⟨i, Nat.le_of_lt h⟩ := by
-  rw [foldrM.loop]
-
-theorem foldrM_loop [Monad m] [LawfulMonad m] (f : Fin (n+1) → α → m α) (x) (h : i+1 ≤ n+1) :
-    foldrM.loop (n+1) f ⟨i+1, h⟩ x =
-      foldrM.loop n (fun j => f j.succ) ⟨i, Nat.le_of_succ_le_succ h⟩ x >>= f 0 := by
-  induction i generalizing x with
-  | zero =>
-    rw [foldrM_loop_zero, foldrM_loop_succ, pure_bind]
-    conv => rhs; rw [←bind_pure (f 0 x)]
-    congr; funext; exact foldrM_loop_zero ..
-  | succ i ih =>
-    rw [foldrM_loop_succ, foldrM_loop_succ, bind_assoc]
-    congr; funext; exact ih ..
-
-@[simp] theorem foldrM_zero [Monad m] (f : Fin 0 → α → m α) (x) : foldrM 0 f x = pure x :=
-  foldrM_loop_zero ..
-
-theorem foldrM_succ [Monad m] [LawfulMonad m] (f : Fin (n+1) → α → m α) (x) :
-    foldrM (n+1) f x = foldrM n (fun i => f i.succ) x >>= f 0 := foldrM_loop ..
-
-/-! ### foldl -/
-
-theorem foldl_loop_lt (f : α → Fin n → α) (x) (h : i < n) :
-    foldl.loop n f x i = foldl.loop n f (f x ⟨i, h⟩) (i+1) := by
-  rw [foldl.loop, dif_pos h]
-
-theorem foldl_loop_eq (f : α → Fin n → α) (x) : foldl.loop n f x n = x := by
-  rw [foldl.loop, dif_neg (Nat.lt_irrefl _)]
-
-theorem foldl_loop (f : α → Fin (n+1) → α) (x) (h : i < n+1) :
-    foldl.loop (n+1) f x i = foldl.loop n (fun x j => f x j.succ) (f x ⟨i, h⟩) i := by
-  if h' : i < n then
-    rw [foldl_loop_lt _ _ h]
-    rw [foldl_loop_lt _ _ h', foldl_loop]; rfl
-  else
-    cases Nat.le_antisymm (Nat.le_of_lt_succ h) (Nat.not_lt.1 h')
-    rw [foldl_loop_lt]
-    rw [foldl_loop_eq, foldl_loop_eq]
-
-@[simp] theorem foldl_zero (f : α → Fin 0 → α) (x) : foldl 0 f x = x :=
-  foldl_loop_eq ..
-
-theorem foldl_succ (f : α → Fin (n+1) → α) (x) :
-    foldl (n+1) f x = foldl n (fun x i => f x i.succ) (f x 0) :=
-  foldl_loop ..
-
-theorem foldl_succ_last (f : α → Fin (n+1) → α) (x) :
-    foldl (n+1) f x = f (foldl n (f · ·.castSucc) x) (last n) := by
-  rw [foldl_succ]
-  induction n generalizing x with
-  | zero => simp [foldl_succ, Fin.last]
-  | succ n ih => rw [foldl_succ, ih (f · ·.succ), foldl_succ]; simp [succ_castSucc]
-
-theorem foldl_eq_foldlM (f : α → Fin n → α) (x) :
-    foldl n f x = foldlM (m:=Id) n f x := by
-  induction n generalizing x <;> simp [foldl_succ, foldlM_succ, *]
-
-/-! ### foldr -/
-
-theorem foldr_loop_zero (f : Fin n → α → α) (x) :
-    foldr.loop n f ⟨0, Nat.zero_le _⟩ x = x := by
-  rw [foldr.loop]
-
-theorem foldr_loop_succ (f : Fin n → α → α) (x) (h : i < n) :
-    foldr.loop n f ⟨i+1, h⟩ x = foldr.loop n f ⟨i, Nat.le_of_lt h⟩ (f ⟨i, h⟩ x) := by
-  rw [foldr.loop]
-
-theorem foldr_loop (f : Fin (n+1) → α → α) (x) (h : i+1 ≤ n+1) :
-    foldr.loop (n+1) f ⟨i+1, h⟩ x =
-      f 0 (foldr.loop n (fun j => f j.succ) ⟨i, Nat.le_of_succ_le_succ h⟩ x) := by
-  induction i generalizing x <;> simp [foldr_loop_zero, foldr_loop_succ, *]
-
-@[simp] theorem foldr_zero (f : Fin 0 → α → α) (x) : foldr 0 f x = x :=
-  foldr_loop_zero ..
-
-theorem foldr_succ (f : Fin (n+1) → α → α) (x) :
-    foldr (n+1) f x = f 0 (foldr n (fun i => f i.succ) x) := foldr_loop ..
-
-theorem foldr_succ_last (f : Fin (n+1) → α → α) (x) :
-    foldr (n+1) f x = foldr n (f ·.castSucc) (f (last n) x) := by
-  induction n generalizing x with
-  | zero => simp [foldr_succ, Fin.last]
-  | succ n ih => rw [foldr_succ, ih (f ·.succ), foldr_succ]; simp [succ_castSucc]
-
-theorem foldr_eq_foldrM (f : Fin n → α → α) (x) :
-    foldr n f x = foldrM (m:=Id) n f x := by
-  induction n <;> simp [foldr_succ, foldrM_succ, *]
-
-theorem foldl_rev (f : Fin n → α → α) (x) :
-    foldl n (fun x i => f i.rev x) x = foldr n f x := by
-  induction n generalizing x with
-  | zero => simp
-  | succ n ih => rw [foldl_succ, foldr_succ_last, ← ih]; simp [rev_succ]
-
-theorem foldr_rev (f : α → Fin n → α) (x) :
-     foldr n (fun i x => f x i.rev) x = foldl n f x := by
-  induction n generalizing x with
-  | zero => simp
-  | succ n ih => rw [foldl_succ_last, foldr_succ, ← ih]; simp [rev_succ]
-
 end Fin

src/Init/Data/Fin/Iterate.lean

@@ -26,7 +26,7 @@ def hIterateFrom (P : Nat → Sort _) {n} (f : ∀(i : Fin n), P i.val → P (i.
   decreasing_by decreasing_trivial_pre_omega
 
 /--
-`hIterate` is a heterogeneous iterative operation that applies a
+`hIterate` is a heterogenous iterative operation that applies a
 index-dependent function `f` to a value `init : P start` a total of
 `stop - start` times to produce a value of type `P stop`.
 
@@ -35,7 +35,7 @@ Concretely, `hIterate start stop f init` is equal to
   init |> f start _ |> f (start+1) _ ... |> f (end-1) _
 ```
 
-Because it is heterogeneous and must return a value of type `P stop`,
+Because it is heterogenous and must return a value of type `P stop`,
 `hIterate` requires proof that `start ≤ stop`.
 
 One can prove properties of `hIterate` using the general theorem
@@ -70,7 +70,7 @@ private theorem hIterateFrom_elim {P : Nat → Sort _}(Q : ∀(i : Nat), P i →
 
 /-
 `hIterate_elim` provides a mechanism for showing that the result of
-`hIterate` satisfies a property `Q stop` by showing that the states
+`hIterate` satisifies a property `Q stop` by showing that the states
 at the intermediate indices `i : start ≤ i < stop` satisfy `Q i`.
 -/
 theorem hIterate_elim {P : Nat → Sort _} (Q : ∀(i : Nat), P i → Prop)

src/Init/Data/Fin/Lemmas.lean

@@ -11,21 +11,22 @@ import Init.ByCases
 import Init.Conv
 import Init.Omega
 
+-- Remove after the next stage0 update
+set_option allowUnsafeReducibility true
+
 namespace Fin
 
-@[deprecated Fin.pos (since := "2024-11-11")]
-theorem size_pos (i : Fin n) : 0 < n := i.pos
+/-- If you actually have an element of `Fin n`, then the `n` is always positive -/
+theorem size_pos (i : Fin n) : 0 < n := Nat.lt_of_le_of_lt (Nat.zero_le _) i.2
 
 theorem mod_def (a m : Fin n) : a % m = Fin.mk (a % m) (Nat.lt_of_le_of_lt (Nat.mod_le _ _) a.2) :=
   rfl
 
-theorem mul_def (a b : Fin n) : a * b = Fin.mk ((a * b) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem mul_def (a b : Fin n) : a * b = Fin.mk ((a * b) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
-theorem sub_def (a b : Fin n) : a - b = Fin.mk (((n - b) + a) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem sub_def (a b : Fin n) : a - b = Fin.mk (((n - b) + a) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
-theorem pos' : ∀ [Nonempty (Fin n)], 0 < n | ⟨i⟩ => i.pos
-
-@[deprecated pos' (since := "2024-11-11")] abbrev size_pos' := @pos'
+theorem size_pos' : ∀ [Nonempty (Fin n)], 0 < n | ⟨i⟩ => i.size_pos
 
 @[simp] theorem is_lt (a : Fin n) : (a : Nat) < n := a.2
 
@@ -53,18 +54,11 @@ theorem eq_mk_iff_val_eq {a : Fin n} {k : Nat} {hk : k < n} :
 
 theorem mk_val (i : Fin n) : (⟨i, i.isLt⟩ : Fin n) = i := Fin.eta ..
 
-@[simp] theorem val_ofNat' (n : Nat) [NeZero n] (a : Nat) :
-  (Fin.ofNat' n a).val = a % n := rfl
+@[simp] theorem val_ofNat' (a : Nat) (is_pos : n > 0) :
+  (Fin.ofNat' a is_pos).val = a % n := rfl
 
-@[simp] theorem ofNat'_self {n : Nat} [NeZero n] : Fin.ofNat' n n = 0 := by
-  ext
-  simp
-  congr
-
-@[simp] theorem ofNat'_val_eq_self [NeZero n] (x : Fin n) : (Fin.ofNat' n x) = x := by
-  ext
-  rw [val_ofNat', Nat.mod_eq_of_lt]
-  exact x.2
+@[deprecated ofNat'_zero_val (since := "2024-02-22")]
+theorem ofNat'_zero_val : (Fin.ofNat' 0 h).val = 0 := Nat.zero_mod _
 
 @[simp] theorem mod_val (a b : Fin n) : (a % b).val = a.val % b.val :=
   rfl
@@ -75,9 +69,6 @@ theorem mk_val (i : Fin n) : (⟨i, i.isLt⟩ : Fin n) = i := Fin.eta ..
 @[simp] theorem modn_val (a : Fin n) (b : Nat) : (a.modn b).val = a.val % b :=
   rfl
 
-@[simp] theorem val_eq_zero (a : Fin 1) : a.val = 0 :=
-  Nat.eq_zero_of_le_zero <| Nat.le_of_lt_succ a.isLt
-
 theorem ite_val {n : Nat} {c : Prop} [Decidable c] {x : c → Fin n} (y : ¬c → Fin n) :
     (if h : c then x h else y h).val = if h : c then (x h).val else (y h).val := by
   by_cases c <;> simp [*]
@@ -130,7 +121,7 @@ theorem mk_le_of_le_val {b : Fin n} {a : Nat} (h : a ≤ b) :
 
 @[simp] theorem mk_lt_mk {x y : Nat} {hx hy} : (⟨x, hx⟩ : Fin n) < ⟨y, hy⟩ ↔ x < y := .rfl
 
-@[simp] theorem val_zero (n : Nat) [NeZero n] : ((0 : Fin n) : Nat) = 0 := rfl
+@[simp] theorem val_zero (n : Nat) : (0 : Fin (n + 1)).1 = 0 := rfl
 
 @[simp] theorem mk_zero : (⟨0, Nat.succ_pos n⟩ : Fin (n + 1)) = 0 := rfl
 
@@ -150,12 +141,6 @@ theorem eq_zero_or_eq_succ {n : Nat} : ∀ i : Fin (n + 1), i = 0 ∨ ∃ j : Fi
 theorem eq_succ_of_ne_zero {n : Nat} {i : Fin (n + 1)} (hi : i ≠ 0) : ∃ j : Fin n, i = j.succ :=
   (eq_zero_or_eq_succ i).resolve_left hi
 
-protected theorem le_antisymm_iff {x y : Fin n} : x = y ↔ x ≤ y ∧ y ≤ x :=
-  Fin.ext_iff.trans Nat.le_antisymm_iff
-
-protected theorem le_antisymm {x y : Fin n} (h1 : x ≤ y) (h2 : y ≤ x) : x = y :=
-  Fin.le_antisymm_iff.2 ⟨h1, h2⟩
-
 @[simp] theorem val_rev (i : Fin n) : rev i = n - (i + 1) := rfl
 
 @[simp] theorem rev_rev (i : Fin n) : rev (rev i) = i := Fin.ext <| by
@@ -177,24 +162,8 @@ theorem rev_eq {n a : Nat} (i : Fin (n + 1)) (h : n = a + i) :
 @[simp] theorem rev_lt_rev {i j : Fin n} : rev i < rev j ↔ j < i := by
   rw [← Fin.not_le, ← Fin.not_le, rev_le_rev]
 
-/-! ### last -/
-
 @[simp] theorem val_last (n : Nat) : last n = n := rfl
 
-@[simp] theorem last_zero : (Fin.last 0 : Fin 1) = 0 := by
-  ext
-  simp
-
-@[simp] theorem zero_eq_last_iff {n : Nat} : (0 : Fin (n + 1)) = last n ↔ n = 0 := by
-  constructor
-  · intro h
-    simp_all [Fin.ext_iff]
-  · rintro rfl
-    simp
-
-@[simp] theorem last_eq_zero_iff {n : Nat} : Fin.last n = 0 ↔ n = 0 := by
-  simp [eq_comm (a := Fin.last n)]
-
 theorem le_last (i : Fin (n + 1)) : i ≤ last n := Nat.le_of_lt_succ i.is_lt
 
 theorem last_pos : (0 : Fin (n + 2)) < last (n + 1) := Nat.succ_pos _
@@ -228,32 +197,10 @@ instance subsingleton_one : Subsingleton (Fin 1) := subsingleton_iff_le_one.2 (b
 
 theorem fin_one_eq_zero (a : Fin 1) : a = 0 := Subsingleton.elim a 0
 
-@[simp] theorem zero_eq_one_iff {n : Nat} [NeZero n] : (0 : Fin n) = 1 ↔ n = 1 := by
-  constructor
-  · intro h
-    simp [Fin.ext_iff] at h
-    change 0 % n = 1 % n at h
-    rw [eq_comm] at h
-    simpa using h
-  · rintro rfl
-    simp
-
-@[simp] theorem one_eq_zero_iff {n : Nat} [NeZero n] : (1 : Fin n) = 0 ↔ n = 1 := by
-  rw [eq_comm]
-  simp
-
-theorem add_def (a b : Fin n) : a + b = Fin.mk ((a + b) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem add_def (a b : Fin n) : a + b = Fin.mk ((a + b) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
 theorem val_add (a b : Fin n) : (a + b).val = (a.val + b.val) % n := rfl
 
-@[simp] protected theorem zero_add [NeZero n] (k : Fin n) : (0 : Fin n) + k = k := by
-  ext
-  simp [Fin.add_def, Nat.mod_eq_of_lt k.2]
-
-@[simp] protected theorem add_zero [NeZero n] (k : Fin n) : k + 0 = k := by
-  ext
-  simp [add_def, Nat.mod_eq_of_lt k.2]
-
 theorem val_add_one_of_lt {n : Nat} {i : Fin n.succ} (h : i < last _) : (i + 1).1 = i + 1 := by
   match n with
   | 0 => cases h
@@ -377,10 +324,6 @@ theorem succ_succ_ne_one (a : Fin n) : Fin.succ (Fin.succ a) ≠ 1 :=
 
 @[simp] theorem cast_mk (h : n = m) (i : Nat) (hn : i < n) : cast h ⟨i, hn⟩ = ⟨i, h ▸ hn⟩ := rfl
 
-@[simp] theorem cast_refl (n : Nat) (h : n = n) : cast h = id := by
-  ext
-  simp
-
 @[simp] theorem cast_trans {k : Nat} (h : n = m) (h' : m = k) {i : Fin n} :
     cast h' (cast h i) = cast (Eq.trans h h') i := rfl
 
@@ -440,7 +383,7 @@ theorem castSucc_lt_iff_succ_le {n : Nat} {i : Fin n} {j : Fin (n + 1)} :
 
 @[simp] theorem succ_last (n : Nat) : (last n).succ = last n.succ := rfl
 
-@[simp] theorem succ_eq_last_succ {n : Nat} {i : Fin n.succ} :
+@[simp] theorem succ_eq_last_succ {n : Nat} (i : Fin n.succ) :
     i.succ = last (n + 1) ↔ i = last n := by rw [← succ_last, succ_inj]
 
 @[simp] theorem castSucc_castLT (i : Fin (n + 1)) (h : (i : Nat) < n) :
@@ -464,10 +407,10 @@ theorem castSucc_lt_last (a : Fin n) : castSucc a < last n := a.is_lt
 theorem castSucc_pos {i : Fin (n + 1)} (h : 0 < i) : 0 < castSucc i := by
   simpa [lt_def] using h
 
-@[simp] theorem castSucc_eq_zero_iff {a : Fin (n + 1)} : castSucc a = 0 ↔ a = 0 := by simp [Fin.ext_iff]
+@[simp] theorem castSucc_eq_zero_iff (a : Fin (n + 1)) : castSucc a = 0 ↔ a = 0 := by simp [Fin.ext_iff]
 
-theorem castSucc_ne_zero_iff {a : Fin (n + 1)} : castSucc a ≠ 0 ↔ a ≠ 0 :=
-  not_congr <| castSucc_eq_zero_iff
+theorem castSucc_ne_zero_iff (a : Fin (n + 1)) : castSucc a ≠ 0 ↔ a ≠ 0 :=
+  not_congr <| castSucc_eq_zero_iff a
 
 theorem castSucc_fin_succ (n : Nat) (j : Fin n) :
     castSucc (Fin.succ j) = Fin.succ (castSucc j) := by simp [Fin.ext_iff]
@@ -489,10 +432,6 @@ theorem succ_castSucc {n : Nat} (i : Fin n) : i.castSucc.succ = castSucc i.succ
 
 @[simp] theorem coe_addNat (m : Nat) (i : Fin n) : (addNat i m : Nat) = i + m := rfl
 
-@[simp] theorem addNat_zero (n : Nat) (i : Fin n) : addNat i 0 = i := by
-  ext
-  simp
-
 @[simp] theorem addNat_one {i : Fin n} : addNat i 1 = i.succ := rfl
 
 theorem le_coe_addNat (m : Nat) (i : Fin n) : m ≤ addNat i m :=
@@ -522,7 +461,7 @@ theorem cast_addNat_left {n n' m : Nat} (i : Fin n') (h : n' + m = n + m) :
 
 theorem le_coe_natAdd (m : Nat) (i : Fin n) : m ≤ natAdd m i := Nat.le_add_right ..
 
-@[simp] theorem natAdd_zero {n : Nat} : natAdd 0 = cast (Nat.zero_add n).symm := by ext; simp
+theorem natAdd_zero {n : Nat} : natAdd 0 = cast (Nat.zero_add n).symm := by ext; simp
 
 /-- For rewriting in the reverse direction, see `Fin.cast_natAdd_right`. -/
 theorem natAdd_cast {n n' : Nat} (m : Nat) (i : Fin n') (h : n' = n) :
@@ -560,19 +499,9 @@ theorem cast_addNat {n : Nat} (m : Nat) (i : Fin n) :
 
 @[simp] theorem natAdd_last {m n : Nat} : natAdd n (last m) = last (n + m) := rfl
 
-@[simp] theorem addNat_last (n : Nat) :
-    addNat (last n) m = cast (by omega) (last (n + m)) := by
-  ext
-  simp
-
 theorem natAdd_castSucc {m n : Nat} {i : Fin m} : natAdd n (castSucc i) = castSucc (natAdd n i) :=
   rfl
 
-@[simp] theorem natAdd_eq_addNat (n : Nat) (i : Fin n) : Fin.natAdd n i = i.addNat n := by
-  ext
-  simp
-  omega
-
 theorem rev_castAdd (k : Fin n) (m : Nat) : rev (castAdd m k) = addNat (rev k) m := Fin.ext <| by
   rw [val_rev, coe_castAdd, coe_addNat, val_rev, Nat.sub_add_comm (Nat.succ_le_of_lt k.is_lt)]
 
@@ -588,15 +517,15 @@ theorem rev_succ (k : Fin n) : rev (succ k) = castSucc (rev k) := k.rev_addNat 1
 @[simp] theorem coe_pred (j : Fin (n + 1)) (h : j ≠ 0) : (j.pred h : Nat) = j - 1 := rfl
 
 @[simp] theorem succ_pred : ∀ (i : Fin (n + 1)) (h : i ≠ 0), (i.pred h).succ = i
-  | ⟨0, _⟩, hi => by simp only [mk_zero, ne_eq, not_true] at hi
-  | ⟨_ + 1, _⟩, _ => rfl
+  | ⟨0, h⟩, hi => by simp only [mk_zero, ne_eq, not_true] at hi
+  | ⟨n + 1, h⟩, hi => rfl
 
 @[simp]
 theorem pred_succ (i : Fin n) {h : i.succ ≠ 0} : i.succ.pred h = i := by
   cases i
   rfl
 
-theorem pred_eq_iff_eq_succ {n : Nat} {i : Fin (n + 1)} (hi : i ≠ 0) {j : Fin n} :
+theorem pred_eq_iff_eq_succ {n : Nat} (i : Fin (n + 1)) (hi : i ≠ 0) (j : Fin n) :
     i.pred hi = j ↔ i = j.succ :=
   ⟨fun h => by simp only [← h, Fin.succ_pred], fun h => by simp only [h, Fin.pred_succ]⟩
 
@@ -638,15 +567,6 @@ theorem pred_add_one (i : Fin (n + 2)) (h : (i : Nat) < n + 1) :
 @[simp] theorem subNat_mk {i : Nat} (h₁ : i < n + m) (h₂ : m ≤ i) :
     subNat m ⟨i, h₁⟩ h₂ = ⟨i - m, Nat.sub_lt_right_of_lt_add h₂ h₁⟩ := rfl
 
-@[simp] theorem subNat_zero (i : Fin n) (h : 0 ≤ (i : Nat)): Fin.subNat 0 i h = i := by
-  ext
-  simp
-
-@[simp] theorem subNat_one_succ (i : Fin (n + 1)) (h : 1 ≤ (i : Nat)) : (subNat 1 i h).succ = i := by
-  ext
-  simp
-  omega
-
 @[simp] theorem pred_castSucc_succ (i : Fin n) :
     pred (castSucc i.succ) (Fin.ne_of_gt (castSucc_pos i.succ_pos)) = castSucc i := rfl
 
@@ -657,7 +577,7 @@ theorem pred_add_one (i : Fin (n + 2)) (h : (i : Nat) < n + 1) :
     subNat m (addNat i m) h = i := Fin.ext <| Nat.add_sub_cancel i m
 
 @[simp] theorem natAdd_subNat_cast {i : Fin (n + m)} (h : n ≤ i) :
-    natAdd n (subNat n (cast (Nat.add_comm ..) i) h) = i := by simp [← cast_addNat]
+    natAdd n (subNat n (cast (Nat.add_comm ..) i) h) = i := by simp [← cast_addNat]; rfl
 
 /-! ### recursion and induction principles -/
 
@@ -825,13 +745,13 @@ theorem addCases_right {m n : Nat} {motive : Fin (m + n) → Sort _} {left right
 
 /-! ### add -/
 
-theorem ofNat'_add [NeZero n] (x : Nat) (y : Fin n) :
-    Fin.ofNat' n x + y = Fin.ofNat' n (x + y.val) := by
+@[simp] theorem ofNat'_add (x : Nat) (lt : 0 < n) (y : Fin n) :
+    Fin.ofNat' x lt + y = Fin.ofNat' (x + y.val) lt := by
   apply Fin.eq_of_val_eq
   simp [Fin.ofNat', Fin.add_def]
 
-theorem add_ofNat' [NeZero n] (x : Fin n) (y : Nat) :
-    x + Fin.ofNat' n y = Fin.ofNat' n (x.val + y) := by
+@[simp] theorem add_ofNat' (x : Fin n) (y : Nat) (lt : 0 < n) :
+    x + Fin.ofNat' y lt = Fin.ofNat' (x.val + y) lt := by
   apply Fin.eq_of_val_eq
   simp [Fin.ofNat', Fin.add_def]
 
@@ -840,21 +760,16 @@ theorem add_ofNat' [NeZero n] (x : Fin n) (y : Nat) :
 protected theorem coe_sub (a b : Fin n) : ((a - b : Fin n) : Nat) = ((n - b) + a) % n := by
   cases a; cases b; rfl
 
-theorem ofNat'_sub [NeZero n] (x : Nat) (y : Fin n) :
-    Fin.ofNat' n x - y = Fin.ofNat' n ((n - y.val) + x) := by
+@[simp] theorem ofNat'_sub (x : Nat) (lt : 0 < n) (y : Fin n) :
+    Fin.ofNat' x lt - y = Fin.ofNat' ((n - y.val) + x) lt := by
   apply Fin.eq_of_val_eq
   simp [Fin.ofNat', Fin.sub_def]
 
-theorem sub_ofNat' [NeZero n] (x : Fin n) (y : Nat) :
-    x - Fin.ofNat' n y = Fin.ofNat' n ((n - y % n) + x.val) := by
+@[simp] theorem sub_ofNat' (x : Fin n) (y : Nat) (lt : 0 < n) :
+    x - Fin.ofNat' y lt = Fin.ofNat' ((n - y % n) + x.val) lt := by
   apply Fin.eq_of_val_eq
   simp [Fin.ofNat', Fin.sub_def]
 
-@[simp] protected theorem sub_self [NeZero n] {x : Fin n} : x - x = 0 := by
-  ext
-  rw [Fin.sub_def]
-  simp
-
 private theorem _root_.Nat.mod_eq_sub_of_lt_two_mul {x n} (h₁ : n ≤ x) (h₂ : x < 2 * n) :
     x % n = x - n := by
   rw [Nat.mod_eq, if_pos (by omega), Nat.mod_eq_of_lt (by omega)]

src/Init/Data/Float.lean

@@ -31,7 +31,7 @@ opaque floatSpec : FloatSpec := {
 structure Float where
   val : floatSpec.float
 
-instance : Nonempty Float := ⟨{ val := floatSpec.val }⟩
+instance : Inhabited Float := ⟨{ val := floatSpec.val }⟩
 
 @[extern "lean_float_add"] opaque Float.add : Float → Float → Float
 @[extern "lean_float_sub"] opaque Float.sub : Float → Float → Float
@@ -47,25 +47,6 @@ def Float.lt : Float → Float → Prop := fun a b =>
 def Float.le : Float → Float → Prop := fun a b =>
   floatSpec.le a.val b.val
 
-/--
-Raw transmutation from `UInt64`.
-
-Floats and UInts have the same endianness on all supported platforms.
-IEEE 754 very precisely specifies the bit layout of floats.
--/
-@[extern "lean_float_of_bits"] opaque Float.ofBits : UInt64 → Float
-
-/--
-Raw transmutation to `UInt64`.
-
-Floats and UInts have the same endianness on all supported platforms.
-IEEE 754 very precisely specifies the bit layout of floats.
-
-Note that this function is distinct from `Float.toUInt64`, which attempts
-to preserve the numeric value, and not the bitwise value.
--/
-@[extern "lean_float_to_bits"] opaque Float.toBits : Float → UInt64
-
 instance : Add Float := ⟨Float.add⟩
 instance : Sub Float := ⟨Float.sub⟩
 instance : Mul Float := ⟨Float.mul⟩
@@ -91,35 +72,21 @@ instance floatDecLt (a b : Float) : Decidable (a < b) := Float.decLt a b
 instance floatDecLe (a b : Float) : Decidable (a ≤ b) := Float.decLe a b
 
 @[extern "lean_float_to_string"] opaque Float.toString : Float → String
-/-- If the given float is non-negative, truncates the value to the nearest non-negative integer.
-If negative or NaN, returns `0`.
-If larger than the maximum value for `UInt8` (including Inf), returns the maximum value of `UInt8`
-(i.e. `UInt8.size - 1`).
--/
+
+/-- If the given float is positive, truncates the value to the nearest positive integer.
+If negative or larger than the maximum value for UInt8, returns 0. -/
 @[extern "lean_float_to_uint8"] opaque Float.toUInt8 : Float → UInt8
-/-- If the given float is non-negative, truncates the value to the nearest non-negative integer.
-If negative or NaN, returns `0`.
-If larger than the maximum value for `UInt16` (including Inf), returns the maximum value of `UInt16`
-(i.e. `UInt16.size - 1`).
--/
+/-- If the given float is positive, truncates the value to the nearest positive integer.
+If negative or larger than the maximum value for UInt16, returns 0. -/
 @[extern "lean_float_to_uint16"] opaque Float.toUInt16 : Float → UInt16
-/-- If the given float is non-negative, truncates the value to the nearest non-negative integer.
-If negative or NaN, returns `0`.
-If larger than the maximum value for `UInt32` (including Inf), returns the maximum value of `UInt32`
-(i.e. `UInt32.size - 1`).
--/
+/-- If the given float is positive, truncates the value to the nearest positive integer.
+If negative or larger than the maximum value for UInt32, returns 0. -/
 @[extern "lean_float_to_uint32"] opaque Float.toUInt32 : Float → UInt32
-/-- If the given float is non-negative, truncates the value to the nearest non-negative integer.
-If negative or NaN, returns `0`.
-If larger than the maximum value for `UInt64` (including Inf), returns the maximum value of `UInt64`
-(i.e. `UInt64.size - 1`).
--/
+/-- If the given float is positive, truncates the value to the nearest positive integer.
+If negative or larger than the maximum value for UInt64, returns 0. -/
 @[extern "lean_float_to_uint64"] opaque Float.toUInt64 : Float → UInt64
-/-- If the given float is non-negative, truncates the value to the nearest non-negative integer.
-If negative or NaN, returns `0`.
-If larger than the maximum value for `USize` (including Inf), returns the maximum value of `USize`
-(i.e. `USize.size - 1`). This value is platform dependent).
--/
+/-- If the given float is positive, truncates the value to the nearest positive integer.
+If negative or larger than the maximum value for USize, returns 0. -/
 @[extern "lean_float_to_usize"] opaque Float.toUSize : Float → USize
 
 @[extern "lean_float_isnan"] opaque Float.isNaN : Float → Bool
@@ -136,9 +103,6 @@ instance : ToString Float where
 
 @[extern "lean_uint64_to_float"] opaque UInt64.toFloat (n : UInt64) : Float
 
-instance : Inhabited Float where
-  default := UInt64.toFloat 0
-
 instance : Repr Float where
   reprPrec n prec := if n < UInt64.toFloat 0 then Repr.addAppParen (toString n) prec else toString n