fix: some inconsistencies in Map grind annotations

This PR fixes a couple of bootstrapping-related hiccups in the newly
added `Std.Do` module. More precisely,

* The `spec` attribute syntax was registered under the wrong name and
its implementation needed to use a different priority parser
* Elaborators and delaborators for `MGoal`, `Triple`, `PostCond` and
`PostCond.total` were broken and are now properly builtin
* `Std.Do` should not transitively import `Std.Tactic.Do.Syntax`

Co-authored-by: Sebastian Graf <sg@lean-fro.org>

.github/workflows/build-template.yml

@@ -82,7 +82,7 @@ jobs:
       - name: CI Merge Checkout
         run: |
           git fetch --depth=1 origin ${{ github.sha }}
-          git checkout FETCH_HEAD flake.nix flake.lock script/prepare-*
+          git checkout FETCH_HEAD flake.nix flake.lock script/prepare-* tests/lean/run/importStructure.lean
         if: github.event_name == 'pull_request'
       # (needs to be after "Checkout" so files don't get overridden)
       - name: Setup emsdk
@@ -104,12 +104,12 @@ jobs:
           # NOTE: must be in sync with `save` below
           path: |
             .ccache
-            ${{ matrix.name == 'Linux Lake' && 'build/stage1/**/*.trace
-            build/stage1/**/*.olean
+            ${{ matrix.name == 'Linux Lake' && false && 'build/stage1/**/*.trace
+            build/stage1/**/*.olean*
             build/stage1/**/*.ilean
             build/stage1/**/*.c
             build/stage1/**/*.c.o*' || '' }}
-          key: ${{ matrix.name }}-build-v3-${{ github.event.pull_request.head.sha }}
+          key: ${{ matrix.name }}-build-v3-${{ github.sha }}
           # fall back to (latest) previous cache
           restore-keys: |
             ${{ matrix.name }}-build-v3
@@ -127,9 +127,12 @@ jobs:
           [ -d build ] || mkdir build
           cd build
           # arguments passed to `cmake`
-          # this also enables githash embedding into stage 1 library
-          OPTIONS=(-DCHECK_OLEAN_VERSION=ON)
-          OPTIONS+=(-DLEAN_EXTRA_MAKE_OPTS=-DwarningAsError=true)
+          OPTIONS=(-DLEAN_EXTRA_MAKE_OPTS=-DwarningAsError=true)
+          if [[ -n '${{ matrix.release }}' ]]; then
+            # this also enables githash embedding into stage 1 library, which prohibits reusing
+            # `.olean`s across commits, so we don't do it in the fast non-release CI
+            OPTIONS+=(-DCHECK_OLEAN_VERSION=ON)
+          fi
           if [[ -n '${{ matrix.cross_target }}' ]]; then
             # used by `prepare-llvm`
             export EXTRA_FLAGS=--target=${{ matrix.cross_target }}
@@ -193,7 +196,7 @@ jobs:
         run: |
           ulimit -c unlimited  # coredumps
           time ctest --preset ${{ matrix.CMAKE_PRESET || 'release' }} --test-dir build/stage1 -j$NPROC --output-junit test-results.xml ${{ matrix.CTEST_OPTIONS }}
-        if: (matrix.wasm || !matrix.cross) && (inputs.check-level >= 1 || matrix.name == 'Linux release')
+        if: (matrix.wasm || !matrix.cross) && (inputs.check-level >= 1 || matrix.test)
       - name: Test Summary
         uses: test-summary/action@v2
         with:
@@ -210,7 +213,7 @@ jobs:
       - name: Check Stage 3
         run: |
           make -C build -j$NPROC check-stage3
-        if: matrix.test-speedcenter
+        if: matrix.check-stage3
       - name: Test Speedcenter Benchmarks
         run: |
           # Necessary for some timing metrics but does not work on Namespace runners
@@ -224,7 +227,7 @@ jobs:
         run: |
           # clean rebuild in case of Makefile changes
           make -C build update-stage0 && rm -rf build/stage* && make -C build -j$NPROC
-        if: matrix.name == 'Linux' && inputs.check-level >= 1
+        if: matrix.check-rebootstrap
       - name: CCache stats
         if: always()
         run: ccache -s
@@ -242,8 +245,8 @@ jobs:
           # NOTE: must be in sync with `restore` above
           path: |
             .ccache
-            ${{ matrix.name == 'Linux Lake' && 'build/stage1/**/*.trace
-            build/stage1/**/*.olean
+            ${{ matrix.name == 'Linux Lake' && false && 'build/stage1/**/*.trace
+            build/stage1/**/*.olean*
             build/stage1/**/*.ilean
             build/stage1/**/*.c
             build/stage1/**/*.c.o*' || '' }}

.github/workflows/ci.yml

@@ -145,6 +145,7 @@ jobs:
             // use large runners where available (original repo)
             let large = ${{ github.repository == 'leanprover/lean4' }};
             const isPr = "${{ github.event_name }}" == "pull_request";
+            const isPushToMaster = "${{ github.event_name }}" == "push" && "${{ github.ref_name }}" == "master";
             let matrix = [
               /* TODO: to be updated to new LLVM
               {
@@ -164,9 +165,17 @@ jobs:
               {
                 // portable release build: use channel with older glibc (2.26)
                 "name": "Linux release",
-                "os": large ? "nscloud-ubuntu-22.04-amd64-4x8" : "ubuntu-latest",
+                "os": large && level < 2 ? "nscloud-ubuntu-22.04-amd64-4x16" : "ubuntu-latest",
                 "release": true,
-                "check-level": 0,
+                // Special handling for release jobs. We want:
+                // 1. To run it in PRs so developers get PR toolchains (so secondary is sufficient)
+                // 2. To skip it in merge queues as it takes longer than the
+                //    Linux lake build and adds little value in the merge queue
+                // 3. To run it in release (obviously)
+                // 4. To run it for pushes to master so that pushes to master have a Linux toolchain
+                //    available as an artifact for Grove to use.
+                "check-level": (isPr || isPushToMaster) ? 0 : 2,
+                "secondary": isPr,
                 "shell": "nix develop .#oldGlibc -c bash -euxo pipefail {0}",
                 "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/19.1.2/lean-llvm-x86_64-linux-gnu.tar.zst",
                 "prepare-llvm": "../script/prepare-llvm-linux.sh lean-llvm*",
@@ -176,21 +185,14 @@ jobs:
               },
               {
                 "name": "Linux Lake",
-                "os": large ? "nscloud-ubuntu-22.04-amd64-4x8" : "ubuntu-latest",
+                "os": large ? "nscloud-ubuntu-22.04-amd64-8x16" : "ubuntu-latest",
                 "check-level": 0,
-                // just a secondary build job for now until false positives can be excluded
-                "secondary": true,
-                "CMAKE_OPTIONS": "-DUSE_LAKE=ON",
-                // TODO: importStructure is not compatible with .olean caching
-                // TODO: why does scopedMacros fail?
-                "CTEST_OPTIONS": "-E 'scopedMacros|importStructure'"
-              },
-              {
-                "name": "Linux",
-                "os": large ? "nscloud-ubuntu-22.04-amd64-4x8" : "ubuntu-latest",
+                "test": true,
+                "check-rebootstrap": level >= 1,
                 "check-stage3": level >= 2,
-                "test-speedcenter": level >= 2,
-                "check-level": 1,
+                // NOTE: `test-speedcenter` currently seems to be broken on `ubuntu-latest`
+                "test-speedcenter": large && level >= 2,
+                "CMAKE_OPTIONS": "-DUSE_LAKE=ON",
               },
               {
                 "name": "Linux Reldebug",
@@ -223,7 +225,8 @@ jobs:
               },
               {
                 "name": "macOS aarch64",
-                "os": "macos-14",
+                // standard GH runner only comes with 7GB so use large runner if possible
+                "os": large ? "nscloud-macos-sonoma-arm64-6x14" : "macos-14",
                 "CMAKE_OPTIONS": "-DLEAN_INSTALL_SUFFIX=-darwin_aarch64",
                 "release": true,
                 "shell": "bash -euxo pipefail {0}",
@@ -231,11 +234,7 @@ jobs:
                 "prepare-llvm": "../script/prepare-llvm-macos.sh lean-llvm*",
                 "binary-check": "otool -L",
                 "tar": "gtar", // https://github.com/actions/runner-images/issues/2619
-                // Special handling for MacOS aarch64, we want:
-                // 1. To run it in PRs so Mac devs get PR toolchains (so secondary is sufficient)
-                // 2. To skip it in merge queues as it takes longer than the Linux build and adds
-                //    little value in the merge queue
-                // 3. To run it in release (obviously)
+                // See above for release job levels
                 "check-level": isPr ? 0 : 2,
                 "secondary": isPr,
               },
@@ -254,7 +253,7 @@ jobs:
               },
               {
                 "name": "Linux aarch64",
-                "os": "nscloud-ubuntu-22.04-arm64-4x8",
+                "os": "nscloud-ubuntu-22.04-arm64-4x16",
                 "CMAKE_OPTIONS": "-DLEAN_INSTALL_SUFFIX=-linux_aarch64",
                 "release": true,
                 "check-level": 2,
@@ -364,7 +363,7 @@ jobs:
         with:
           path: artifacts
       - name: Release
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@da05d552573ad5aba039eaac05058a918a7bf631
         with:
           files: artifacts/*/*
           fail_on_unmatched_files: true
@@ -408,7 +407,7 @@ 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@da05d552573ad5aba039eaac05058a918a7bf631
         with:
           body_path: diff.md
           prerelease: true
@@ -425,6 +424,6 @@ jobs:
           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
+          gh workflow -R leanprover-community/mathlib4-nightly-testing run nightly_bump_toolchain.yml
         env:
           GITHUB_TOKEN: ${{ secrets.MATHLIB4_BOT }}

.github/workflows/grove.yml

@@ -0,0 +1,161 @@
+name: Grove
+
+on:
+  workflow_run: # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#workflow_run
+    workflows: [CI]
+    types: [completed]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  grove-build:
+    runs-on: ubuntu-latest
+    if: github.event.workflow_run.conclusion == 'success' && github.repository == 'leanprover/lean4'
+
+    steps:
+      - name: Retrieve information about the original workflow
+        uses: potiuk/get-workflow-origin@v1_1 # https://github.com/marketplace/actions/get-workflow-origin
+        # This action is deprecated and archived, but it seems hard to find a
+        # better solution for getting the PR number
+        # see https://github.com/orgs/community/discussions/25220 for some discussion
+        id: workflow-info
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          sourceRunId: ${{ github.event.workflow_run.id }}
+
+      - name: Check if should run
+        id: should-run
+        run: |
+          # Check if it's a push to master (no PR number and target branch is master)
+          if [ -z "${{ steps.workflow-info.outputs.pullRequestNumber }}" ]; then
+            if [ "${{ github.event.workflow_run.head_branch }}" = "master" ]; then
+              echo "Push to master detected. Skipping for now, to be enabled later."
+              echo "should-run=false" >> "$GITHUB_OUTPUT"
+            else
+              echo "Push to non-master branch, skipping"
+              echo "should-run=false" >> "$GITHUB_OUTPUT"
+            fi
+          else
+            # Check if it's a PR with grove label
+            PR_LABELS='${{ steps.workflow-info.outputs.pullRequestLabels }}'
+            if echo "$PR_LABELS" | grep -q '"grove"'; then
+              echo "PR with grove label detected"
+              echo "should-run=true" >> "$GITHUB_OUTPUT"
+            else
+              echo "PR without grove label, skipping"
+              echo "should-run=false" >> "$GITHUB_OUTPUT"
+            fi
+          fi
+
+      - name: Fetch upstream invalidated facts
+        if: ${{ steps.should-run.outputs.should-run == 'true' && steps.workflow-info.outputs.pullRequestNumber != '' }}
+        id: fetch-upstream
+        uses: TwoFx/grove-action/fetch-upstream@v0.3
+        with:
+          artifact-name: grove-invalidated-facts
+          base-ref: master
+
+      - name: Download toolchain for this commit
+        if: ${{ steps.should-run.outputs.should-run == 'true' }}
+        id: download-toolchain
+        uses: dawidd6/action-download-artifact@v11
+        with:
+          commit: ${{ steps.workflow-info.outputs.sourceHeadSha }}
+          workflow: ci.yml
+          path: artifacts
+          name: build-Linux.*
+          name_is_regexp: true
+
+      - name: Unpack toolchain
+        if: ${{ steps.should-run.outputs.should-run == 'true' }}
+        id: unpack-toolchain
+        run: |
+          cd artifacts
+          # Find the tar.zst file
+          TAR_FILE=$(find . -name "lean-*.tar.zst" -type f | head -1)
+          if [ -z "$TAR_FILE" ]; then
+            echo "Error: No lean-*.tar.zst file found"
+            exit 1
+          fi
+          echo "Found archive: $TAR_FILE"
+
+          # Extract the archive
+          tar --zstd -xf "$TAR_FILE"
+
+          # Find the extracted directory name
+          LEAN_DIR=$(find . -maxdepth 1 -name "lean-*" -type d | head -1)
+          if [ -z "$LEAN_DIR" ]; then
+            echo "Error: No lean-* directory found after extraction"
+            exit 1
+          fi
+          echo "Extracted directory: $LEAN_DIR"
+          echo "lean-dir=$LEAN_DIR" >> "$GITHUB_OUTPUT"
+
+      - name: Build
+        if: ${{ steps.should-run.outputs.should-run == 'true' }}
+        id: build
+        uses: TwoFx/grove-action/build@v0.3
+        with:
+          project-path: doc/std/grove
+          script-name: grove-stdlib
+          invalidated-facts-artifact-name: grove-invalidated-facts
+          comment-artifact-name: grove-comment
+          toolchain-id: lean4
+          toolchain-path: artifacts/${{ steps.unpack-toolchain.outputs.lean-dir }}
+          project-ref: ${{ steps.workflow-info.outputs.sourceHeadSha }}
+
+      # deploy-alias computes a URL component for the PR preview. This
+      # is so we can have a stable name to use for feedback on draft
+      # material.
+      - id: deploy-alias
+        if: ${{ steps.should-run.outputs.should-run == 'true' }}
+        uses: actions/github-script@v7
+        name: Compute Alias
+        with:
+          result-encoding: string
+          script: |
+            if (process.env.PR) {
+                return `pr-${process.env.PR}`
+            } else {
+                return 'deploy-preview-main';
+            }
+        env:
+          PR: ${{ steps.workflow-info.outputs.pullRequestNumber }}
+
+      - name: Deploy to Netlify
+        if: ${{ steps.should-run.outputs.should-run == 'true' }}
+        id: deploy-draft
+        uses: nwtgck/actions-netlify@v3.0
+        with:
+          publish-dir: ${{ steps.build.outputs.out-path }}
+          production-deploy: false
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          alias: ${{ steps.deploy-alias.outputs.result }}
+          enable-commit-comment: false
+          enable-pull-request-comment: false
+          fails-without-credentials: true
+          enable-github-deployment: false
+          enable-commit-status: false
+        env:
+          NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}
+          NETLIFY_SITE_ID: "1cacfa39-a11c-467c-99e7-2e01d7b4089e"
+
+      # actions-netlify cannot add deploy links to a PR because it assumes a
+      # pull_request context, not a workflow_run context, see
+      # https://github.com/nwtgck/actions-netlify/issues/545
+      # We work around by using a comment to post the latest link
+      - name: "Comment on PR with preview links"
+        uses: marocchino/sticky-pull-request-comment@v2
+        if: ${{ steps.should-run.outputs.should-run == 'true' && steps.workflow-info.outputs.pullRequestNumber != '' }}
+        with:
+          number: ${{ env.PR_NUMBER }}
+          header: preview-comment
+          recreate: true
+          message: |
+            [Grove](${{ steps.deploy-draft.outputs.deploy-url }}) for revision ${{ steps.workflow-info.outputs.sourceHeadSha }}.
+
+            ${{ steps.build.outputs.comment-text }}
+        env:
+          PR_NUMBER: ${{ steps.workflow-info.outputs.pullRequestNumber }}
+          PR_HEADSHA: ${{ steps.workflow-info.outputs.sourceHeadSha }}

.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@v9 # https://github.com/marketplace/actions/download-workflow-artifact
+        uses: dawidd6/action-download-artifact@v10 # https://github.com/marketplace/actions/download-workflow-artifact
         with:
           run_id: ${{ github.event.workflow_run.id }}
           path: artifacts
@@ -48,19 +48,30 @@ jobs:
           git -C lean4.git remote add origin https://github.com/${{ github.repository_owner }}/lean4.git
           git -C lean4.git fetch -n origin master
           git -C lean4.git fetch -n origin "${{ steps.workflow-info.outputs.sourceHeadSha }}"
+          
+          # Create both the original tag and the SHA-suffixed tag
+          SHORT_SHA="${{ steps.workflow-info.outputs.sourceHeadSha }}"
+          SHORT_SHA="${SHORT_SHA:0:7}"
+          
+          # Export the short SHA for use in subsequent steps
+          echo "SHORT_SHA=${SHORT_SHA}" >> "$GITHUB_ENV"
+
           git -C lean4.git tag -f pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }} "${{ steps.workflow-info.outputs.sourceHeadSha }}"
+          git -C lean4.git tag -f pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-"${SHORT_SHA}" "${{ steps.workflow-info.outputs.sourceHeadSha }}"
+          
           git -C lean4.git remote add pr-releases https://foo:'${{ secrets.PR_RELEASES_TOKEN }}'@github.com/${{ github.repository_owner }}/lean4-pr-releases.git
           git -C lean4.git push -f pr-releases pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}
+          git -C lean4.git push -f pr-releases pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-"${SHORT_SHA}"
       - name: Delete existing release if present
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         run: |
-          # Try to delete any existing release for the current PR.
+          # Try to delete any existing release for the current PR (just the version without the SHA suffix).
           gh release delete --repo ${{ github.repository_owner }}/lean4-pr-releases pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }} -y || true
         env:
           GH_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
-      - name: Release
+      - name: Release (short format)
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@da05d552573ad5aba039eaac05058a918a7bf631
         with:
           name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }}
           # There are coredumps files here as well, but all in deeper subdirectories.
@@ -73,7 +84,22 @@ jobs:
           # The token used here must have `workflow` privileges.
           GITHUB_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
 
-      - name: Report release status
+      - name: Release (SHA-suffixed format)
+        if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
+        uses: softprops/action-gh-release@da05d552573ad5aba039eaac05058a918a7bf631
+        with:
+          name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }} (${{ steps.workflow-info.outputs.sourceHeadSha }})
+          # There are coredumps files here as well, but all in deeper subdirectories.
+          files: artifacts/*/*
+          fail_on_unmatched_files: true
+          draft: false
+          tag_name: pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}
+          repository: ${{ github.repository_owner }}/lean4-pr-releases
+        env:
+          # The token used here must have `workflow` privileges.
+          GITHUB_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
+
+      - name: Report release status (short format)
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         uses: actions/github-script@v7
         with:
@@ -87,6 +113,20 @@ jobs:
               description: "${{ github.repository_owner }}/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}",
             });
 
+      - name: Report release status (SHA-suffixed format)
+        if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            await github.rest.repos.createCommitStatus({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              sha: "${{ steps.workflow-info.outputs.sourceHeadSha }}",
+              state: "success",
+              context: "PR toolchain (SHA-suffixed)",
+              description: "${{ github.repository_owner }}/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}",
+            });
+
       - name: Add label
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         uses: actions/github-script@v7
@@ -127,7 +167,7 @@ jobs:
             echo "The merge base of this PR coincides with the nightly release"
 
             BATTERIES_REMOTE_TAGS="$(git ls-remote https://github.com/leanprover-community/batteries.git nightly-testing-"$MOST_RECENT_NIGHTLY")"
-            MATHLIB_REMOTE_TAGS="$(git ls-remote https://github.com/leanprover-community/mathlib4.git nightly-testing-"$MOST_RECENT_NIGHTLY")"
+            MATHLIB_REMOTE_TAGS="$(git ls-remote https://github.com/leanprover-community/mathlib4-nightly-testing.git nightly-testing-"$MOST_RECENT_NIGHTLY")"
 
             if [[ -n "$BATTERIES_REMOTE_TAGS" ]]; then
               echo "... and Batteries has a 'nightly-testing-$MOST_RECENT_NIGHTLY' tag."
@@ -282,16 +322,18 @@ jobs:
           if [ "$EXISTS" = "0" ]; then
             echo "Branch does not exist, creating it."
             git switch -c lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }} "$BASE"
-            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}" > lean-toolchain
+            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
             git commit -m "Update lean-toolchain for testing https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           else
-            echo "Branch already exists, pushing an empty commit."
+            echo "Branch already exists, updating lean-toolchain."
             git switch lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}
             # The Batteries `nightly-testing` or `nightly-testing-YYYY-MM-DD` branch 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 "$BASE" --strategy-option ours --no-commit --allow-unrelated-histories
-            git commit --allow-empty -m "Trigger CI for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
+            git add lean-toolchain
+            git commit -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 
       - name: Push changes
@@ -313,7 +355,7 @@ jobs:
         if: steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true'
         uses: actions/checkout@v4
         with:
-          repository: leanprover-community/mathlib4
+          repository: leanprover-community/mathlib4-nightly-testing
           token: ${{ secrets.MATHLIB4_BOT }}
           ref: nightly-testing
           fetch-depth: 0 # This ensures we check out all tags and branches.
@@ -346,21 +388,23 @@ jobs:
           if [ "$EXISTS" = "0" ]; then
             echo "Branch does not exist, creating it."
             git switch -c lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }} "$BASE"
-            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}" > lean-toolchain
+            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
             git add lean-toolchain
             sed -i 's,require "leanprover-community" / "batteries" @ git ".\+",require "leanprover-community" / "batteries" @ git "lean-pr-testing-${{ steps.workflow-info.outputs.pullRequestNumber }}",' lakefile.lean
             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 $BASE and bumping Batteries."
+            echo "Branch already exists, updating lean-toolchain and bumping Batteries."
             git switch lean-pr-testing-${{ 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 "$BASE" --strategy-option ours --no-commit --allow-unrelated-histories
+            echo "leanprover/lean4-pr-releases:pr-release-${{ steps.workflow-info.outputs.pullRequestNumber }}-${{ env.SHORT_SHA }}" > lean-toolchain
+            git add lean-toolchain
             lake update batteries
             git add lake-manifest.json
-            git commit --allow-empty -m "Trigger CI for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
+            git commit -m "Update lean-toolchain for https://github.com/leanprover/lean4/pull/${{ steps.workflow-info.outputs.pullRequestNumber }}"
           fi
 
       - name: Push changes

.gitignore

@@ -6,7 +6,6 @@
 lake-manifest.json
 /build
 /src/lakefile.toml
-/tests/lakefile.toml
 /lakefile.toml
 GPATH
 GRTAGS

doc/dev/index.md

@@ -85,5 +85,6 @@ such that changing files in `Init` doesn't force a full rebuild of `Lean`.
 You can test a Lean PR against Mathlib and Batteries by rebasing your PR
 on to `nightly-with-mathlib` branch. (It is fine to force push after rebasing.)
 CI will generate a branch of Mathlib and Batteries called `lean-pr-testing-NNNN`
-that uses the toolchain for your PR, and will report back to the Lean PR with results from Mathlib CI.
+on the `leanprover-community/mathlib4-nightly-testing` fork of Mathlib.
+This branch uses the toolchain for your PR, and will report back to the Lean PR with results from Mathlib CI.
 See https://leanprover-community.github.io/contribute/tags_and_branches.html for more details.

doc/dev/release_checklist.md

@@ -50,7 +50,7 @@ We'll use `v4.6.0` as the intended release version as a running example.
     - Re-running `script/release_checklist.py` will then create the tag `v4.6.0` from `master`/`main` and push it (unless `toolchain-tag: false` in the `release_repos.yml` file)
     - `script/release_checklist.py` will then merge the tag `v4.6.0` into the `stable` branch and push it (unless `stable-branch: false` in the `release_repos.yml` file).
   - Special notes on repositories with exceptional requirements:
-    - `doc-gen4` has addition dependencies which we do not update at each toolchain release, although occasionally these break and need to be updated manually.
+    - `doc-gen4` has additional dependencies which we do not update at each toolchain release, although occasionally these break and need to be updated manually.
     - `verso`:
       - The `subverso` dependency is unusual in that it needs to be compatible with _every_ Lean release simultaneously.
         Usually you don't need to do anything.
@@ -94,6 +94,8 @@ We'll use `v4.6.0` as the intended release version as a running example.
 
 This checklist walks you through creating the first release candidate for a version of Lean.
 
+For subsequent release candidates, the process is essentially the same, but we start out with the `releases/v4.7.0` branch already created.
+
 We'll use `v4.7.0-rc1` as the intended release version in this example.
 
 - Decide which nightly release you want to turn into a release candidate.
@@ -112,7 +114,7 @@ We'll use `v4.7.0-rc1` as the intended release version in this example.
     git fetch nightly tag nightly-2024-02-29
     git checkout nightly-2024-02-29
     git checkout -b releases/v4.7.0
-    git push --set-upstream origin releases/v4.18.0
+    git push --set-upstream origin releases/v4.7.0
     ```
 - In `src/CMakeLists.txt`,
   - verify that you see `set(LEAN_VERSION_MINOR 7)` (for whichever `7` is appropriate); this should already have been updated when the development cycle began.

doc/std/grove/.gitignore

@@ -0,0 +1,4 @@
+/.lake
+!lake-manifest.json
+metadata.json
+invalidated.json

doc/std/grove/GroveStdlib/Generated.lean

@@ -0,0 +1,13 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Generated
+
+def restoreState : RestoreStateM Unit := do
+  return ()

doc/std/grove/GroveStdlib/Std.lean

@@ -0,0 +1,31 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import GroveStdlib.Std.CoreTypesAndOperations
+import GroveStdlib.Std.LanguageConstructs
+import GroveStdlib.Std.Libraries
+import GroveStdlib.Std.OperatingSystemAbstractions
+
+open Grove.Framework Widget
+
+namespace GroveStdlib
+
+namespace Std
+
+def introduction : Node :=
+  .text "Welcome to the interactive Lean standard library outline!"
+
+end Std
+
+def std : Node :=
+  .section "stdlib" "The Lean standard library" #[
+    Std.introduction,
+    Std.coreTypesAndOperations,
+    Std.languageConstructs,
+    Std.libraries,
+    Std.operatingSystemAbstractions
+  ]
+
+end GroveStdlib

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

@@ -0,0 +1,28 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+import GroveStdlib.Std.CoreTypesAndOperations.BasicTypes
+import GroveStdlib.Std.CoreTypesAndOperations.Containers
+import GroveStdlib.Std.CoreTypesAndOperations.Numbers
+import GroveStdlib.Std.CoreTypesAndOperations.StringsAndFormatting
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std
+
+namespace CoreTypesAndOperations
+
+end CoreTypesAndOperations
+
+def coreTypesAndOperations : Node :=
+  .section "core-types-and-operations" "Core types and operations" #[
+    CoreTypesAndOperations.basicTypes,
+    CoreTypesAndOperations.containers,
+    CoreTypesAndOperations.numbers,
+    CoreTypesAndOperations.stringsAndFormatting
+  ]
+
+end GroveStdlib.Std

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

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.CoreTypesAndOperations
+
+namespace BasicTypes
+
+end BasicTypes
+
+def basicTypes : Node :=
+  .section "basic-types" "Basic types" #[]
+
+end GroveStdlib.Std.CoreTypesAndOperations

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

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.CoreTypesAndOperations
+
+namespace Containers
+
+end Containers
+
+def containers : Node :=
+  .section "containers" "Containers" #[]
+
+end GroveStdlib.Std.CoreTypesAndOperations

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

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.CoreTypesAndOperations
+
+namespace Numbers
+
+end Numbers
+
+def numbers : Node :=
+  .section "numbers" "Numbers" #[]
+
+end GroveStdlib.Std.CoreTypesAndOperations

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

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.CoreTypesAndOperations
+
+namespace StringsAndFormatting
+
+end StringsAndFormatting
+
+def stringsAndFormatting : Node :=
+  .section "strings-and-formatting" "Strings and formatting" #[]
+
+end GroveStdlib.Std.CoreTypesAndOperations

doc/std/grove/GroveStdlib/Std/LanguageConstructs.lean

@@ -0,0 +1,26 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+import GroveStdlib.Std.LanguageConstructs.ComparisonOrderingHashing
+import GroveStdlib.Std.LanguageConstructs.Monads
+import GroveStdlib.Std.LanguageConstructs.RangesAndIterators
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std
+
+namespace LanguageConstructs
+
+end LanguageConstructs
+
+def languageConstructs : Node :=
+  .section "language-constructs" "Language constructs" #[
+    LanguageConstructs.comparisonOrderingHashing,
+    LanguageConstructs.monads,
+    LanguageConstructs.rangesAndIterators
+  ]
+
+end GroveStdlib.Std

doc/std/grove/GroveStdlib/Std/LanguageConstructs/ComparisonOrderingHashing.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.LanguageConstructs
+
+namespace ComparisonOrderingHashing
+
+end ComparisonOrderingHashing
+
+def comparisonOrderingHashing : Node :=
+  .section "comparison-ordering-hashing" "Comparison, ordering, hashing" #[]
+
+end GroveStdlib.Std.LanguageConstructs

doc/std/grove/GroveStdlib/Std/LanguageConstructs/Monads.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.LanguageConstructs
+
+namespace Monads
+
+end Monads
+
+def monads : Node :=
+  .section "monads" "Monads" #[]
+
+end GroveStdlib.Std.LanguageConstructs

doc/std/grove/GroveStdlib/Std/LanguageConstructs/RangesAndIterators.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.LanguageConstructs
+
+namespace RangesAndIterators
+
+end RangesAndIterators
+
+def rangesAndIterators : Node :=
+  .section "ranges-and-iterators" "Ranges and iterators" #[]
+
+end GroveStdlib.Std.LanguageConstructs

doc/std/grove/GroveStdlib/Std/Libraries.lean

@@ -0,0 +1,24 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+import GroveStdlib.Std.Libraries.DateAndTime
+import GroveStdlib.Std.Libraries.RandomNumbers
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std
+
+namespace Libraries
+
+end Libraries
+
+def libraries : Node :=
+  .section "libraries" "Libraries" #[
+    Libraries.dateAndTime,
+    Libraries.randomNumbers
+  ]
+
+end GroveStdlib.Std

doc/std/grove/GroveStdlib/Std/Libraries/DateAndTime.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.Libraries
+
+namespace DateAndTime
+
+end DateAndTime
+
+def dateAndTime : Node :=
+  .section "date-and-time" "Date and time" #[]
+
+end GroveStdlib.Std.Libraries

doc/std/grove/GroveStdlib/Std/Libraries/RandomNumbers.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.Libraries
+
+namespace RandomNumbers
+
+end RandomNumbers
+
+def randomNumbers : Node :=
+  .section "random-numbers" "Random numbers" #[]
+
+end GroveStdlib.Std.Libraries

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions.lean

@@ -0,0 +1,30 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+import GroveStdlib.Std.OperatingSystemAbstractions.AsynchronousIO
+import GroveStdlib.Std.OperatingSystemAbstractions.BasicIO
+import GroveStdlib.Std.OperatingSystemAbstractions.ConcurrencyAndParallelism
+import GroveStdlib.Std.OperatingSystemAbstractions.EnvironmentFileSystemProcesses
+import GroveStdlib.Std.OperatingSystemAbstractions.Locales
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std
+
+namespace OperatingSystemAbstractions
+
+end OperatingSystemAbstractions
+
+def operatingSystemAbstractions : Node :=
+  .section "operating-system-abstractions" "Operating system abstractions" #[
+    OperatingSystemAbstractions.asynchronousIO,
+    OperatingSystemAbstractions.basicIO,
+    OperatingSystemAbstractions.concurrencyAndParallelism,
+    OperatingSystemAbstractions.environmentFileSystemProcesses,
+    OperatingSystemAbstractions.locales
+  ]
+
+end GroveStdlib.Std

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions/AsynchronousIO.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.OperatingSystemAbstractions
+
+namespace AsynchronousIO
+
+end AsynchronousIO
+
+def asynchronousIO : Node :=
+  .section "asynchronous-io" "Asynchronous I/O" #[]
+
+end GroveStdlib.Std.OperatingSystemAbstractions

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions/BasicIO.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.OperatingSystemAbstractions
+
+namespace BasicIO
+
+end BasicIO
+
+def basicIO : Node :=
+  .section "basic-io" "Basic I/O" #[]
+
+end GroveStdlib.Std.OperatingSystemAbstractions

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions/ConcurrencyAndParallelism.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.OperatingSystemAbstractions
+
+namespace ConcurrencyAndParallelism
+
+end ConcurrencyAndParallelism
+
+def concurrencyAndParallelism : Node :=
+  .section "concurrency-and-parallelism" "Concurrency and parallelism" #[]
+
+end GroveStdlib.Std.OperatingSystemAbstractions

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions/EnvironmentFileSystemProcesses.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.OperatingSystemAbstractions
+
+namespace EnvironmentFileSystemProcesses
+
+end EnvironmentFileSystemProcesses
+
+def environmentFileSystemProcesses : Node :=
+  .section "environment-filesystem-processes" "Environment, file system, processes" #[]
+
+end GroveStdlib.Std.OperatingSystemAbstractions

doc/std/grove/GroveStdlib/Std/OperatingSystemAbstractions/Locales.lean

@@ -0,0 +1,19 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import Grove.Framework
+
+open Grove.Framework Widget
+
+namespace GroveStdlib.Std.OperatingSystemAbstractions
+
+namespace Locales
+
+end Locales
+
+def locales : Node :=
+  .section "locales" "Locales" #[]
+
+end GroveStdlib.Std.OperatingSystemAbstractions

doc/std/grove/Main.lean

@@ -0,0 +1,18 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Markus Himmel
+-/
+import GroveStdlib.Std
+import GroveStdlib.Generated
+
+def config : Grove.Framework.Project.Configuration where
+  projectNamespace := `GroveStdlib
+
+def project : Grove.Framework.Project where
+  config := config
+  rootNode := GroveStdlib.std
+  restoreState := GroveStdlib.Generated.restoreState
+
+def main (args : List String) : IO UInt32 :=
+  Grove.Framework.main project #[`Init, `Std, `Lean] args

doc/std/grove/README.md

@@ -0,0 +1,3 @@
+# Standard library QA
+
+This directory contains the [Grove](github.com/TwoFX/grove) data files for the standard library.

doc/std/grove/grove-local.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+lake exe grove-stdlib --full metadata.json
+cd .lake/packages/grove/frontend
+npm install
+if [ -f "../../../../invalidated.json" ]; then
+    GROVE_DATA_LOCATION=../../../../metadata.json GROVE_UPSTREAM_INVALIDATED_FACTS_LOCATION=../../../../invalidated.json npm run dev
+else
+    GROVE_DATA_LOCATION=../../../../metadata.json npm run dev
+fi

doc/std/grove/lake-manifest.json

@@ -0,0 +1,25 @@
+{"version": "1.1.0",
+ "packagesDir": ".lake/packages",
+ "packages":
+ [{"url": "https://github.com/TwoFx/grove.git",
+   "type": "git",
+   "subDir": "backend",
+   "scope": "",
+   "rev": "78110476d9c76abd4103d91a0ae3f89405558065",
+   "name": "grove",
+   "manifestFile": "lake-manifest.json",
+   "inputRev": "master",
+   "inherited": false,
+   "configFile": "lakefile.toml"},
+  {"url": "https://github.com/leanprover/lean4-cli",
+   "type": "git",
+   "subDir": null,
+   "scope": "leanprover",
+   "rev": "1604206fcd0462da9a241beeac0e2df471647435",
+   "name": "Cli",
+   "manifestFile": "lake-manifest.json",
+   "inputRev": "main",
+   "inherited": true,
+   "configFile": "lakefile.toml"}],
+ "name": "grovestdlib",
+ "lakeDir": ".lake"}

doc/std/grove/lakefile.toml

@@ -0,0 +1,18 @@
+name = "grovestdlib"
+version = "0.1.0"
+defaultTargets = ["grove-stdlib"]
+
+[[require]]
+name = "grove"
+git = "https://github.com/TwoFx/grove.git"
+rev = "master"
+subDir = "backend"
+
+[[lean_lib]]
+name = "GroveStdlib"
+root = "GroveStdlib"
+
+[[lean_exe]]
+name = "grove-stdlib"
+supportInterpreter = true
+root = "Main"

doc/std/grove/lean-toolchain

@@ -0,0 +1 @@
+lean4

doc/std/grove/update_invalidated.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+lake exe grove-stdlib --invalidated invalidated.json

script/bench.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# We benchmark against stage 2 to test new optimizations.
+timeout -s KILL 1h time bash -c 'mkdir -p build/release; cd build/release; cmake ../.. && make -j$(nproc) stage2' 1>&2
+export PATH=$PWD/build/release/stage2/bin:$PATH
+cd tests/bench
+timeout -s KILL 1h time temci exec --config speedcenter.yaml --in speedcenter.exec.velcom.yaml 1>&2
+temci report run_output.yaml --reporter codespeed2

script/mathlib-bench

@@ -5,8 +5,11 @@ set -euo pipefail
 
 [ $# -eq 1 ] || (echo "usage: $0 <lean4 PR #>"; exit 1)
 
+echo "Warning: the speedcenter is probably not listening on mathlib4-nightly-testing yet."
+echo "If you're using this script, please contact @kim-em or @Kha to get this set up, and then remove this notice."
+
 LEAN_PR=$1
-PR_RESPONSE=$(gh api repos/leanprover-community/mathlib4/pulls -X POST -f head=lean-pr-testing-$LEAN_PR -f base=nightly-testing -f title="leanprover/lean4#$LEAN_PR benchmarking" -f draft=true -f body="ignore me")
+PR_RESPONSE=$(gh api repos/leanprover-community/mathlib4-nightly-testing/pulls -X POST -f head=lean-pr-testing-$LEAN_PR -f base=nightly-testing -f title="leanprover/lean4#$LEAN_PR benchmarking" -f draft=true -f body="ignore me")
 PR_NUMBER=$(echo "$PR_RESPONSE" | jq '.number')
-echo "opened https://github.com/leanprover-community/mathlib4/pull/$PR_NUMBER"
-gh api repos/leanprover-community/mathlib4/issues/$PR_NUMBER/comments -X POST -f body="!bench" > /dev/null
+echo "opened https://github.com/leanprover-community/mathlib4-nightly-testing/pull/$PR_NUMBER"
+gh api repos/leanprover-community/mathlib4-nightly-testing/issues/$PR_NUMBER/comments -X POST -f body="!bench" > /dev/null

script/prepare-llvm-mingw.sh

@@ -50,5 +50,4 @@ echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='--sysroot ROOT -L ROOT/lib -Wl,-Bstatic
 # 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'"
 # do not set `LEAN_CC` for tests
-echo -n " -DAUTO_THREAD_FINALIZATION=OFF -DSTAGE0_AUTO_THREAD_FINALIZATION=OFF"
 echo -n " -DLEAN_TEST_VARS=''"

script/release_checklist.py

@@ -53,6 +53,23 @@ def tag_exists(repo_url, tag_name, github_token):
     matching_tags = response.json()
     return any(tag["ref"] == f"refs/tags/{tag_name}" for tag in matching_tags)
 
+def commit_hash_for_tag(repo_url, tag_name, github_token):
+    # Use /git/matching-refs/tags/ to get all matching tags
+    api_url = repo_url.replace("https://github.com/", "https://api.github.com/repos/") + f"/git/matching-refs/tags/{tag_name}"
+    headers = {'Authorization': f'token {github_token}'} if github_token else {}
+    response = requests.get(api_url, headers=headers)
+
+    if response.status_code != 200:
+        return False
+
+    # Check if any of the returned refs exactly match our tag
+    matching_tags = response.json()
+    matching_commits = [tag["object"]["sha"] for tag in matching_tags if tag["ref"] == f"refs/tags/{tag_name}"]
+    if len(matching_commits) != 1:
+        return None
+    else:
+        return matching_commits[0]
+
 def release_page_exists(repo_url, tag_name, github_token):
     api_url = repo_url.replace("https://github.com/", "https://api.github.com/repos/") + f"/releases/tags/{tag_name}"
     headers = {'Authorization': f'token {github_token}'} if github_token else {}
@@ -286,6 +303,14 @@ def main():
         lean4_success = False
     else:
         print(f"  ✅ Tag {toolchain} exists")
+        commit_hash = commit_hash_for_tag(lean_repo_url, toolchain, github_token)
+        SHORT_HASH_LENGTH = 7 # Lake abbreviates the Lean commit to 7 characters.
+        if commit_hash is None:
+            print(f"  ❌ Could not resolve tag {toolchain} to a commit.")
+            lean4_success = False
+        elif commit_hash[0] == '0' and commit_hash[:SHORT_HASH_LENGTH].isnumeric():
+            print(f"  ❌ Short commit hash {commit_hash[:SHORT_HASH_LENGTH]} is numeric and starts with 0, causing issues for version parsing. Try regenerating the last commit to get a new hash.")
+            lean4_success = False
 
     if not release_page_exists(lean_repo_url, toolchain, github_token):
         print(f"  ❌ Release page for {toolchain} does not exist")

script/release_steps.py

@@ -94,6 +94,7 @@ def generate_script(repo, version, config):
             "echo 'This repo has nightly-testing infrastructure'",
             f"git merge origin/bump/{version.split('-rc')[0]}",
             "echo 'Please resolve any conflicts.'",
+            "grep nightly-testing lakefile.* && echo 'Please ensure the lakefile does not include nightly-testing versions.'",
             ""
         ])
     if re.search(r'rc\d+$', version) and repo_name in ["verso", "reference-manual"]:

src/CMakeLists.txt

@@ -10,7 +10,7 @@ endif()
 include(ExternalProject)
 project(LEAN CXX C)
 set(LEAN_VERSION_MAJOR 4)
-set(LEAN_VERSION_MINOR 21)
+set(LEAN_VERSION_MINOR 22)
 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'")
@@ -58,9 +58,6 @@ option(USE_GITHASH        "GIT_HASH"           ON)
 option(INSTALL_LICENSE "INSTALL_LICENSE" ON)
 # When ON we install a copy of cadical
 option(INSTALL_CADICAL "Install a copy of cadical" ON)
-# When ON thread storage is automatically finalized, it assumes platform support pthreads.
-# This option is important when using Lean as library that is invoked from a different programming language (e.g., Haskell).
-option(AUTO_THREAD_FINALIZATION "AUTO_THREAD_FINALIZATION" ON)
 
 # FLAGS for disabling optimizations and debugging
 option(FREE_VAR_RANGE_OPT  "FREE_VAR_RANGE_OPT"   ON)
@@ -182,10 +179,6 @@ else()
   string(APPEND LEAN_EXTRA_CXX_FLAGS " -D LEAN_MULTI_THREAD")
 endif()
 
-if(AUTO_THREAD_FINALIZATION AND NOT MSVC)
-  string(APPEND LEAN_EXTRA_CXX_FLAGS " -D LEAN_AUTO_THREAD_FINALIZATION")
-endif()
-
 # Set Module Path
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules")
 

src/Init.lean

@@ -37,6 +37,7 @@ import Init.Ext
 import Init.Omega
 import Init.MacroTrace
 import Init.Grind
+import Init.GrindInstances
 import Init.While
 import Init.Syntax
 import Init.Internal

src/Init/Classical.lean

@@ -45,7 +45,7 @@ theorem em (p : Prop) : p ∨ ¬p :=
     | Or.inr h, _ => Or.inr h
     | _, Or.inr h => Or.inr h
     | Or.inl hut, Or.inl hvf =>
-      have hne : u ≠ v := by simp [hvf, hut, true_ne_false]
+      have hne : u ≠ v := by simp [hvf, hut]
       Or.inl hne
   have p_implies_uv : p → u = v :=
     fun hp =>

src/Init/Coe.lean

@@ -7,6 +7,7 @@ module
 
 prelude
 import Init.Prelude
+meta import Init.Prelude
 set_option linter.missingDocs true -- keep it documented
 
 /-!

src/Init/Control/Id.lean

@@ -62,4 +62,7 @@ protected def run (x : Id α) : α := x
 instance [OfNat α n] : OfNat (Id α) n :=
   inferInstanceAs (OfNat α n)
 
+instance {m : Type u → Type v} [Pure m] : MonadLiftT Id m where
+  monadLift x := pure x.run
+
 end Id

src/Init/Control/Lawful/Basic.lean

@@ -50,7 +50,7 @@ attribute [simp] id_map
   (comp_map _ _ _).symm
 
 theorem Functor.map_unit [Functor f] [LawfulFunctor f] {a : f PUnit} : (fun _ => PUnit.unit) <$> a = a := by
-  simp [map]
+  simp
 
 /--
 An applicative functor satisfies the laws of an applicative functor.
@@ -148,7 +148,7 @@ attribute [simp] pure_bind bind_assoc bind_pure_comp
 attribute [grind] pure_bind
 
 @[simp] theorem bind_pure [Monad m] [LawfulMonad m] (x : m α) : x >>= pure = x := by
-  show x >>= (fun a => pure (id a)) = x
+  change x >>= (fun a => pure (id a)) = x
   rw [bind_pure_comp, id_map]
 
 /--

src/Init/Control/Lawful/Instances.lean

@@ -58,7 +58,7 @@ protected theorem bind_pure_comp [Monad m] (f : α → β) (x : ExceptT ε m α)
   intros; rfl
 
 protected theorem seqLeft_eq {α β ε : Type u} {m : Type u → Type v} [Monad m] [LawfulMonad m] (x : ExceptT ε m α) (y : ExceptT ε m β) : x <* y = const β <$> x <*> y := by
-  show (x >>= fun a => y >>= fun _ => pure a) = (const (α := α) β <$> x) >>= fun f => f <$> y
+  change (x >>= fun a => y >>= fun _ => pure a) = (const (α := α) β <$> x) >>= fun f => f <$> y
   rw [← ExceptT.bind_pure_comp]
   apply ext
   simp [run_bind]
@@ -67,10 +67,10 @@ protected theorem seqLeft_eq {α β ε : Type u} {m : Type u → Type v} [Monad
   | Except.error _ => simp
   | Except.ok _ =>
     simp [←bind_pure_comp]; apply bind_congr; intro b;
-    cases b <;> simp [comp, Except.map, const]
+    cases b <;> simp [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 <$> x <*> y := by
-  show (x >>= fun _ => y) = (const α id <$> x) >>= fun f => f <$> y
+  change (x >>= fun _ => y) = (const α id <$> x) >>= fun f => f <$> y
   rw [← ExceptT.bind_pure_comp]
   apply ext
   simp [run_bind]
@@ -206,15 +206,15 @@ theorem run_bind_lift {α σ : Type u} [Monad m] [LawfulMonad m] (x : m α) (f :
     (monadMap @f x : StateT σ m α).run s = monadMap @f (x.run s) := rfl
 
 @[simp] theorem run_seq {α β σ : Type u} [Monad m] [LawfulMonad m] (f : StateT σ m (α → β)) (x : StateT σ m α) (s : σ) : (f <*> x).run s = (f.run s >>= fun fs => (fun (p : α × σ) => (fs.1 p.1, p.2)) <$> x.run fs.2) := by
-  show (f >>= fun g => g <$> x).run s = _
+  change (f >>= fun g => g <$> x).run s = _
   simp
 
 @[simp] theorem run_seqRight [Monad m] (x : StateT σ m α) (y : StateT σ m β) (s : σ) : (x *> y).run s = (x.run s >>= fun p => y.run p.2) := by
-  show (x >>= fun _ => y).run s = _
+  change (x >>= fun _ => y).run s = _
   simp
 
 @[simp] theorem run_seqLeft {α β σ : Type u} [Monad m] (x : StateT σ m α) (y : StateT σ m β) (s : σ) : (x <* y).run s = (x.run s >>= fun p => y.run p.2 >>= fun p' => pure (p.1, p'.2)) := by
-  show (x >>= fun a => y >>= fun _ => pure a).run s = _
+  change (x >>= fun a => y >>= fun _ => pure a).run s = _
   simp
 
 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

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

@@ -11,6 +11,7 @@ import all Init.Control.Except
 import all Init.Control.ExceptCps
 import all Init.Control.StateRef
 import all Init.Control.StateCps
+import all Init.Control.Id
 import Init.Control.Lawful.MonadLift.Lemmas
 import Init.Control.Lawful.Instances
 
@@ -135,3 +136,11 @@ instance {ε : Type u} [Monad m] [LawfulMonad m] : LawfulMonadLift m (ExceptCpsT
     simp only [bind_assoc]
 
 end ExceptCpsT
+
+namespace Id
+
+instance [Monad m] [LawfulMonad m] : LawfulMonadLiftT Id m where
+  monadLift_pure a := by simp [monadLift]
+  monadLift_bind a f := by simp [monadLift]
+
+end Id

src/Init/Conv.lean

@@ -9,7 +9,7 @@ module
 
 prelude
 import Init.Tactics
-import Init.Meta
+meta import Init.Meta
 
 namespace Lean.Parser.Tactic.Conv
 
@@ -339,6 +339,12 @@ This is the conv mode version of the `lift_lets` tactic.
 -/
 syntax (name := liftLets) "lift_lets " optConfig : conv
 
+/--
+Transforms `let` expressions into `have` expressions within th etarget expression when possible.
+This is the conv mode version of the `let_to_have` tactic.
+-/
+syntax (name := letToHave) "let_to_have" : conv
+
 /--
 `conv => ...` allows the user to perform targeted rewriting on a goal or hypothesis,
 by focusing on particular subexpressions.

src/Init/Core.lean

@@ -8,7 +8,7 @@ notation, basic datatypes and type classes
 module
 
 prelude
-import Init.Prelude
+meta import Init.Prelude
 import Init.SizeOf
 set_option linter.missingDocs true -- keep it documented
 
@@ -95,7 +95,8 @@ structure Thunk (α : Type u) : Type u where
   -/
   mk ::
   /-- Extract the getter function out of a thunk. Use `Thunk.get` instead. -/
-  private fn : Unit → α
+  -- The field is public so as to allow computation through it.
+  fn : Unit → α
 
 attribute [extern "lean_mk_thunk"] Thunk.mk
 
@@ -117,6 +118,10 @@ Computed values are cached, so the value is not recomputed.
 @[extern "lean_thunk_get_own"] protected def Thunk.get (x : @& Thunk α) : α :=
   x.fn ()
 
+-- Ensure `Thunk.fn` is still computable even if it shouldn't be accessed directly.
+@[inline] private def Thunk.fnImpl (x : Thunk α) : Unit → α := fun _ => x.get
+@[csimp] private theorem Thunk.fn_eq_fnImpl : @Thunk.fn = @Thunk.fnImpl := rfl
+
 /--
 Constructs a new thunk that forces `x` and then applies `x` to the result. Upon forcing, the result
 of `f` is cached and the reference to the thunk `x` is dropped.
@@ -2247,7 +2252,7 @@ theorem funext {α : Sort u} {β : α → Sort v} {f g : (x : α) → β x}
     Quot.liftOn f
       (fun (f : ∀ (x : α), β x) => f x)
       (fun _ _ h => h x)
-  show extfunApp (Quot.mk eqv f) = extfunApp (Quot.mk eqv g)
+  change extfunApp (Quot.mk eqv f) = extfunApp (Quot.mk eqv g)
   exact congrArg extfunApp (Quot.sound h)
 
 /--

src/Init/Data.lean

@@ -46,3 +46,6 @@ import Init.Data.NeZero
 import Init.Data.Function
 import Init.Data.RArray
 import Init.Data.Vector
+import Init.Data.Iterators
+import Init.Data.Range.Polymorphic
+import Init.Data.Slice

src/Init/Data/AC.lean

@@ -209,7 +209,7 @@ theorem Context.evalList_sort_congr
   induction c generalizing a b with
   | nil => simp [sort.loop, h₂]
   | cons c _  ih =>
-    simp [sort.loop]; apply ih; simp [evalList_insert ctx h, evalList]
+    simp [sort.loop]; apply ih; simp [evalList_insert ctx h]
     cases a with
     | nil => apply absurd h₃; simp
     | cons a as =>
@@ -282,7 +282,7 @@ theorem Context.toList_nonEmpty (e : Expr) : e.toList ≠ [] := by
     simp [Expr.toList]
     cases h : l.toList with
     | nil => contradiction
-    | cons => simp [List.append]
+    | cons => simp
 
 theorem Context.unwrap_isNeutral
   {ctx : Context α}
@@ -328,13 +328,13 @@ theorem Context.eval_toList (ctx : Context α) (e : Expr) : evalList α ctx e.to
   induction e with
   | var x => rfl
   | op l r ih₁ ih₂ =>
-    simp [evalList, Expr.toList, eval, ←ih₁, ←ih₂]
+    simp [Expr.toList, eval, ←ih₁, ←ih₂]
     apply evalList_append <;> apply toList_nonEmpty
 
 theorem Context.eval_norm (ctx : Context α) (e : Expr) : evalList α ctx (norm ctx e) = eval α ctx e := by
   simp [norm]
   cases h₁ : ContextInformation.isIdem ctx <;> cases h₂ : ContextInformation.isComm ctx <;>
-  simp_all [evalList_removeNeutrals, eval_toList, toList_nonEmpty, evalList_mergeIdem, evalList_sort]
+  simp_all [evalList_removeNeutrals, eval_toList, evalList_mergeIdem, evalList_sort]
 
 theorem Context.eq_of_norm (ctx : Context α) (a b : Expr) (h : norm ctx a == norm ctx b) : eval α ctx a = eval α ctx b := by
   have h := congrArg (evalList α ctx) (eq_of_beq h)

src/Init/Data/Array/Attach.lean

@@ -68,15 +68,15 @@ well-founded recursion mechanism to prove that the function terminates.
     l.toArray.pmap f H = (l.pmap f (by simpa using H)).toArray := by
   simp [pmap]
 
-@[simp] theorem toList_attachWith {xs : Array α} {P : α → Prop} {H : ∀ x ∈ xs, P x} :
+@[simp, grind =] theorem toList_attachWith {xs : Array α} {P : α → Prop} {H : ∀ x ∈ xs, P x} :
    (xs.attachWith P H).toList = xs.toList.attachWith P (by simpa [mem_toList_iff] using H) := by
   simp [attachWith]
 
-@[simp] theorem toList_attach {xs : Array α} :
+@[simp, grind =] theorem toList_attach {xs : Array α} :
     xs.attach.toList = xs.toList.attachWith (· ∈ xs) (by simp [mem_toList_iff]) := by
   simp [attach]
 
-@[simp] theorem toList_pmap {xs : Array α} {P : α → Prop} {f : ∀ a, P a → β} {H : ∀ a ∈ xs, P a} :
+@[simp, grind =] theorem toList_pmap {xs : Array α} {P : α → Prop} {f : ∀ a, P a → β} {H : ∀ a ∈ xs, P a} :
     (xs.pmap f H).toList = xs.toList.pmap f (fun a m => H a (mem_def.mpr m)) := by
   simp [pmap]
 
@@ -92,16 +92,16 @@ well-founded recursion mechanism to prove that the function terminates.
   intro a m h₁ h₂
   congr
 
-@[simp] theorem pmap_empty {P : α → Prop} (f : ∀ a, P a → β) : pmap f #[] (by simp) = #[] := rfl
+@[simp, grind =] 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) (xs : Array α) (h : ∀ b ∈ xs.push a, P b) :
+@[simp, grind =] theorem pmap_push {P : α → Prop} (f : ∀ a, P a → β) (a : α) (xs : Array α) (h : ∀ b ∈ xs.push a, P b) :
     pmap f (xs.push a) h =
       (pmap f xs (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, grind =] 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, grind =] 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) =
@@ -122,11 +122,13 @@ theorem pmap_congr_left {p q : α → Prop} {f : ∀ a, p a → β} {g : ∀ a,
   simp only [List.pmap_toArray, mk.injEq]
   rw [List.pmap_congr_left _ h]
 
+@[grind =]
 theorem map_pmap {p : α → Prop} {g : β → γ} {f : ∀ a, p a → β} {xs : Array α} (H) :
     map g (pmap f xs H) = pmap (fun a h => g (f a h)) xs H := by
   cases xs
   simp [List.map_pmap]
 
+@[grind =]
 theorem pmap_map {p : β → Prop} {g : ∀ b, p b → γ} {f : α → β} {xs : Array α} (H) :
     pmap g (map f xs) H = pmap (fun a h => g (f a) h) xs fun _ h => H _ (mem_map_of_mem h) := by
   cases xs
@@ -142,18 +144,18 @@ theorem attachWith_congr {xs ys : Array α} (w : xs = ys) {P : α → Prop} {H :
   subst w
   simp
 
-@[simp] theorem attach_push {a : α} {xs : Array α} :
+@[simp, grind =] theorem attach_push {a : α} {xs : Array α} :
     (xs.push a).attach =
       (xs.attach.map (fun ⟨x, h⟩ => ⟨x, mem_push_of_mem a h⟩)).push ⟨a, by simp⟩ := by
   cases xs
   rw [attach_congr (List.push_toArray _ _)]
   simp [Function.comp_def]
 
-@[simp] theorem attachWith_push {a : α} {xs : Array α} {P : α → Prop} {H : ∀ x ∈ xs.push a, P x} :
+@[simp, grind =] theorem attachWith_push {a : α} {xs : Array α} {P : α → Prop} {H : ∀ x ∈ xs.push a, P x} :
     (xs.push a).attachWith P H =
       (xs.attachWith P (fun x h => by simp at H; exact H x (.inl h))).push ⟨a, H a (by simp)⟩ := by
   cases xs
-  simp [attachWith_congr (List.push_toArray _ _)]
+  simp
 
 theorem pmap_eq_map_attach {p : α → Prop} {f : ∀ a, p a → β} {xs : Array α} (H) :
     pmap f xs H = xs.attach.map fun x => f x.1 (H _ x.2) := by
@@ -189,38 +191,39 @@ theorem attachWith_map_subtype_val {p : α → Prop} {xs : Array α} (H : ∀ a
     (xs.attachWith p H).map Subtype.val = xs := by
   cases xs; simp
 
-@[simp]
+@[simp, grind]
 theorem mem_attach (xs : Array α) : ∀ x, x ∈ xs.attach
   | ⟨a, h⟩ => by
     have := mem_map.1 (by rw [attach_map_subtype_val] <;> exact h)
     rcases this with ⟨⟨_, _⟩, m, rfl⟩
     exact m
 
-@[simp]
+@[simp, grind]
 theorem mem_attachWith {xs : Array α} {q : α → Prop} (H) (x : {x // q x}) :
     x ∈ xs.attachWith q H ↔ x.1 ∈ xs := by
   cases xs
   simp
 
-@[simp]
+@[simp, grind =]
 theorem mem_pmap {p : α → Prop} {f : ∀ a, p a → β} {xs H b} :
     b ∈ pmap f xs H ↔ ∃ (a : _) (h : a ∈ xs), f a (H a h) = b := by
   simp only [pmap_eq_map_attach, mem_map, mem_attach, true_and, Subtype.exists, eq_comm]
 
+@[grind]
 theorem mem_pmap_of_mem {p : α → Prop} {f : ∀ a, p a → β} {xs H} {a} (h : a ∈ xs) :
     f a (H a h) ∈ pmap f xs H := by
   rw [mem_pmap]
   exact ⟨a, h, rfl⟩
 
-@[simp]
+@[simp, grind =]
 theorem size_pmap {p : α → Prop} {f : ∀ a, p a → β} {xs H} : (pmap f xs H).size = xs.size := by
   cases xs; simp
 
-@[simp]
+@[simp, grind =]
 theorem size_attach {xs : Array α} : xs.attach.size = xs.size := by
   cases xs; simp
 
-@[simp]
+@[simp, grind =]
 theorem size_attachWith {p : α → Prop} {xs : Array α} {H} : (xs.attachWith p H).size = xs.size := by
   cases xs; simp
 
@@ -252,13 +255,13 @@ theorem attachWith_ne_empty_iff {xs : Array α} {P : α → Prop} {H : ∀ a ∈
     xs.attachWith P H ≠ #[] ↔ xs ≠ #[] := by
   cases xs; simp
 
-@[simp]
+@[simp, grind =]
 theorem getElem?_pmap {p : α → Prop} {f : ∀ a, p a → β} {xs : Array α} (h : ∀ a ∈ xs, p a) (i : Nat) :
     (pmap f xs h)[i]? = Option.pmap f xs[i]? fun x H => h x (mem_of_getElem? H) := by
   cases xs; simp
 
 -- The argument `f` is explicit to allow rewriting from right to left.
-@[simp]
+@[simp, grind =]
 theorem getElem_pmap {p : α → Prop} (f : ∀ a, p a → β) {xs : Array α} (h : ∀ a ∈ xs, p a) {i : Nat}
     (hi : i < (pmap f xs h).size) :
     (pmap f xs h)[i] =
@@ -266,57 +269,59 @@ theorem getElem_pmap {p : α → Prop} (f : ∀ a, p a → β) {xs : Array α} (
         (h _ (getElem_mem (@size_pmap _ _ p f xs h ▸ hi))) := by
   cases xs; simp
 
-@[simp]
+@[simp, grind =]
 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]
+@[simp, grind =]
 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]
+@[simp, grind =]
 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 _ _ h
 
-@[simp]
+@[simp, grind =]
 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
 
-@[simp] theorem pmap_attach {xs : Array α} {p : {x // x ∈ xs} → Prop} {f : ∀ a, p a → β} (H) :
+@[simp, grind =] theorem pmap_attach {xs : Array α} {p : {x // x ∈ xs} → Prop} {f : ∀ a, p a → β} (H) :
     pmap f xs.attach H =
       xs.pmap (P := fun a => ∃ h : a ∈ xs, p ⟨a, h⟩)
         (fun a h => f ⟨a, h.1⟩ h.2) (fun a h => ⟨h, H ⟨a, h⟩ (by simp)⟩) := by
   ext <;> simp
 
-@[simp] theorem pmap_attachWith {xs : Array α} {p : {x // q x} → Prop} {f : ∀ a, p a → β} (H₁ H₂) :
+@[simp, grind =] theorem pmap_attachWith {xs : Array α} {p : {x // q x} → Prop} {f : ∀ a, p a → β} (H₁ H₂) :
     pmap f (xs.attachWith q H₁) H₂ =
       xs.pmap (P := fun a => ∃ h : q a, p ⟨a, h⟩)
         (fun a h => f ⟨a, h.1⟩ h.2) (fun a h => ⟨H₁ _ h, H₂ ⟨a, H₁ _ h⟩ (by simpa)⟩) := by
   ext <;> simp
 
+@[grind =]
 theorem foldl_pmap {xs : Array α} {P : α → Prop} {f : (a : α) → P a → β}
     (H : ∀ (a : α), a ∈ xs → P a) (g : γ → β → γ) (x : γ) :
     (xs.pmap f H).foldl g x = xs.attach.foldl (fun acc a => g acc (f a.1 (H _ a.2))) x := by
   rw [pmap_eq_map_attach, foldl_map]
 
+@[grind =]
 theorem foldr_pmap {xs : Array α} {P : α → Prop} {f : (a : α) → P a → β}
     (H : ∀ (a : α), a ∈ xs → P a) (g : β → γ → γ) (x : γ) :
     (xs.pmap f H).foldr g x = xs.attach.foldr (fun a acc => g (f a.1 (H _ a.2)) acc) x := by
   rw [pmap_eq_map_attach, foldr_map]
 
-@[simp] theorem foldl_attachWith
+@[simp, grind =] theorem foldl_attachWith
     {xs : Array α} {q : α → Prop} (H : ∀ a, a ∈ xs → q a) {f : β → { x // q x} → β} {b} (w : stop = xs.size) :
     (xs.attachWith q H).foldl f b 0 stop = xs.attach.foldl (fun b ⟨a, h⟩ => f b ⟨a, H _ h⟩) b := by
   subst w
   rcases xs with ⟨xs⟩
   simp [List.foldl_attachWith, List.foldl_map]
 
-@[simp] theorem foldr_attachWith
+@[simp, grind =] theorem foldr_attachWith
     {xs : Array α} {q : α → Prop} (H : ∀ a, a ∈ xs → q a) {f : { x // q x} → β → β} {b} (w : start = xs.size) :
     (xs.attachWith q H).foldr f b start 0 = xs.attach.foldr (fun a acc => f ⟨a.1, H _ a.2⟩ acc) b := by
   subst w
@@ -337,7 +342,7 @@ theorem foldl_attach {xs : Array α} {f : β → α → β} {b : β} :
     xs.attach.foldl (fun acc t => f acc t.1) b = xs.foldl f b := by
   rcases xs with ⟨xs⟩
   simp only [List.attach_toArray, List.attachWith_mem_toArray, List.size_toArray,
-    List.length_pmap, List.foldl_toArray', mem_toArray, List.foldl_subtype]
+    List.foldl_toArray', mem_toArray, List.foldl_subtype]
   congr
   ext
   simpa using fun a => List.mem_of_getElem? a
@@ -356,23 +361,25 @@ theorem foldr_attach {xs : Array α} {f : α → β → β} {b : β} :
     xs.attach.foldr (fun t acc => f t.1 acc) b = xs.foldr f b := by
   rcases xs with ⟨xs⟩
   simp only [List.attach_toArray, List.attachWith_mem_toArray, List.size_toArray,
-    List.length_pmap, List.foldr_toArray', mem_toArray, List.foldr_subtype]
+    List.foldr_toArray', mem_toArray, List.foldr_subtype]
   congr
   ext
   simpa using fun a => List.mem_of_getElem? a
 
+@[grind =]
 theorem attach_map {xs : Array α} {f : α → β} :
     (xs.map f).attach = xs.attach.map (fun ⟨x, h⟩ => ⟨f x, mem_map_of_mem h⟩) := by
   cases xs
   ext <;> simp
 
+@[grind =]
 theorem attachWith_map {xs : Array α} {f : α → β} {P : β → Prop} (H : ∀ (b : β), b ∈ xs.map f → P b) :
     (xs.map f).attachWith P H = (xs.attachWith (P ∘ f) (fun _ h => H _ (mem_map_of_mem h))).map
       fun ⟨x, h⟩ => ⟨f x, h⟩ := by
   cases xs
   simp [List.attachWith_map]
 
-@[simp] theorem map_attachWith {xs : Array α} {P : α → Prop} {H : ∀ (a : α), a ∈ xs → P a}
+@[simp, grind =] theorem map_attachWith {xs : Array α} {P : α → Prop} {H : ∀ (a : α), a ∈ xs → P a}
     {f : { x // P x } → β} :
     (xs.attachWith P H).map f = xs.attach.map fun ⟨x, h⟩ => f ⟨x, H _ h⟩ := by
   cases xs <;> simp_all
@@ -393,6 +400,7 @@ theorem map_attach_eq_pmap {xs : Array α} {f : { x // x ∈ xs } → β} :
 @[deprecated map_attach_eq_pmap (since := "2025-02-09")]
 abbrev map_attach := @map_attach_eq_pmap
 
+@[grind =]
 theorem attach_filterMap {xs : Array α} {f : α → Option β} :
     (xs.filterMap f).attach = xs.attach.filterMap
       fun ⟨x, h⟩ => (f x).pbind (fun b m => some ⟨b, mem_filterMap.mpr ⟨x, h, m⟩⟩) := by
@@ -400,6 +408,7 @@ theorem attach_filterMap {xs : Array α} {f : α → Option β} :
   rw [attach_congr List.filterMap_toArray]
   simp [List.attach_filterMap, List.map_filterMap, Function.comp_def]
 
+@[grind =]
 theorem attach_filter {xs : Array α} (p : α → Bool) :
     (xs.filter p).attach = xs.attach.filterMap
       fun x => if w : p x.1 then some ⟨x.1, mem_filter.mpr ⟨x.2, w⟩⟩ else none := by
@@ -409,7 +418,7 @@ theorem attach_filter {xs : Array α} (p : α → Bool) :
 
 -- We are still missing here `attachWith_filterMap` and `attachWith_filter`.
 
-@[simp]
+@[simp, grind =]
 theorem filterMap_attachWith {q : α → Prop} {xs : Array α} {f : {x // q x} → Option β} (H)
     (w : stop = (xs.attachWith q H).size) :
     (xs.attachWith q H).filterMap f 0 stop = xs.attach.filterMap (fun ⟨x, h⟩ => f ⟨x, H _ h⟩) := by
@@ -417,7 +426,7 @@ theorem filterMap_attachWith {q : α → Prop} {xs : Array α} {f : {x // q x}
   cases xs
   simp [Function.comp_def]
 
-@[simp]
+@[simp, grind =]
 theorem filter_attachWith {q : α → Prop} {xs : Array α} {p : {x // q x} → Bool} (H)
     (w : stop = (xs.attachWith q H).size) :
     (xs.attachWith q H).filter p 0 stop =
@@ -426,6 +435,7 @@ theorem filter_attachWith {q : α → Prop} {xs : Array α} {p : {x // q x} →
   cases xs
   simp [Function.comp_def, List.filter_map]
 
+@[grind =]
 theorem pmap_pmap {p : α → Prop} {q : β → Prop} {g : ∀ a, p a → β} {f : ∀ b, q b → γ} {xs} (H₁ H₂) :
     pmap f (pmap g xs H₁) H₂ =
       pmap (α := { x // x ∈ xs }) (fun a h => f (g a h) (H₂ (g a h) (mem_pmap_of_mem a.2))) xs.attach
@@ -433,7 +443,7 @@ theorem pmap_pmap {p : α → Prop} {q : β → Prop} {g : ∀ a, p a → β} {f
   cases xs
   simp [List.pmap_pmap, List.pmap_map]
 
-@[simp] theorem pmap_append {p : ι → Prop} {f : ∀ a : ι, p a → α} {xs ys : Array ι}
+@[simp, grind =] theorem pmap_append {p : ι → Prop} {f : ∀ a : ι, p a → α} {xs ys : Array ι}
     (h : ∀ a ∈ xs ++ ys, p a) :
     (xs ++ ys).pmap f h =
       (xs.pmap f fun a ha => h a (mem_append_left ys ha)) ++
@@ -448,7 +458,7 @@ theorem pmap_append' {p : α → Prop} {f : ∀ a : α, p a → β} {xs ys : Arr
       xs.pmap f h₁ ++ ys.pmap f h₂ :=
   pmap_append _
 
-@[simp] theorem attach_append {xs ys : Array α} :
+@[simp, grind =] 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
@@ -456,59 +466,62 @@ theorem pmap_append' {p : α → Prop} {f : ∀ a : α, p a → β} {xs ys : Arr
   rw [attach_congr (List.append_toArray _ _)]
   simp [List.attach_append, Function.comp_def]
 
-@[simp] theorem attachWith_append {P : α → Prop} {xs ys : Array α}
+@[simp, grind =] 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 [attachWith]
 
-@[simp] theorem pmap_reverse {P : α → Prop} {f : (a : α) → P a → β} {xs : Array α}
+@[simp, grind =] 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
 
+@[grind =]
 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}
+@[simp, grind =] 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
 
+@[grind =]
 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} :
+@[simp, grind =] 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
 
+@[grind =]
 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}
+@[simp, grind =] 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}
+@[simp, grind =] 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? h)⟩) := by
   cases xs
   simp
 
-@[simp]
+@[simp, grind =]
 theorem back?_attach {xs : Array α} :
     xs.attach.back? = xs.back?.pbind fun a h => some ⟨a, mem_of_back? h⟩ := by
   cases xs
@@ -526,7 +539,7 @@ theorem countP_attachWith {p : α → Prop} {q : α → Bool} {xs : Array α} {H
   cases xs
   simp
 
-@[simp]
+@[simp, grind =]
 theorem count_attach [BEq α] {xs : Array α} {a : {x // x ∈ xs}} :
     xs.attach.count a = xs.count ↑a := by
   rcases xs with ⟨xs⟩
@@ -535,13 +548,13 @@ theorem count_attach [BEq α] {xs : Array α} {a : {x // x ∈ xs}} :
   simp only [Subtype.beq_iff]
   rw [List.countP_pmap, List.countP_attach (p := (fun x => x == a.1)), List.count]
 
-@[simp]
+@[simp, grind =]
 theorem count_attachWith [BEq α] {p : α → Prop} {xs : Array α} (H : ∀ a ∈ xs, p a) {a : {x // p x}} :
     (xs.attachWith p H).count a = xs.count ↑a := by
   cases xs
   simp
 
-@[simp] theorem countP_pmap {p : α → Prop} {g : ∀ a, p a → β} {f : β → Bool} {xs : Array α} (H₁) :
+@[simp, grind =] theorem countP_pmap {p : α → Prop} {g : ∀ a, p a → β} {f : β → Bool} {xs : Array α} (H₁) :
     (xs.pmap g H₁).countP f =
       xs.attach.countP (fun ⟨a, m⟩ => f (g a (H₁ a m))) := by
   simp [pmap_eq_map_attach, countP_map, Function.comp_def]
@@ -690,7 +703,7 @@ and simplifies these to the function directly taking the value.
     {f : { x // p x } → Array β} {g : α → Array β} (hf : ∀ x h, f ⟨x, h⟩ = g x) :
     (xs.flatMap f) = xs.unattach.flatMap g := by
   cases xs
-  simp only [List.size_toArray, List.flatMap_toArray, List.unattach_toArray, List.length_unattach,
+  simp only [List.flatMap_toArray, List.unattach_toArray, 
     mk.injEq]
   rw [List.flatMap_subtype]
   simp [hf]

src/Init/Data/Array/Basic.lean

@@ -246,7 +246,7 @@ def swap (xs : Array α) (i j : @& Nat) (hi : i < xs.size := by get_elem_tactic)
   xs'.set j v₁ (Nat.lt_of_lt_of_eq hj (size_set _).symm)
 
 @[simp] theorem size_swap {xs : Array α} {i j : Nat} {hi hj} : (xs.swap i j hi hj).size = xs.size := by
-  show ((xs.set i xs[j]).set j xs[i]
+  change ((xs.set i xs[j]).set j xs[i]
     (Nat.lt_of_lt_of_eq hj (size_set _).symm)).size = xs.size
   rw [size_set, size_set]
 
@@ -1788,7 +1788,7 @@ decreasing_by simp_wf; exact Nat.sub_succ_lt_self _ _ h
   induction xs, i, h using Array.eraseIdx.induct with
   | @case1 xs i h h' xs' ih =>
     unfold eraseIdx
-    simp +zetaDelta [h', xs', ih]
+    simp +zetaDelta [h', ih]
   | case2 xs i h h' =>
     unfold eraseIdx
     simp [h']

src/Init/Data/Array/Bootstrap.lean

@@ -119,13 +119,13 @@ abbrev pop_toList := @Array.toList_pop
 @[simp] theorem toList_empty : (#[] : Array α).toList = [] := rfl
 
 @[simp, grind =] theorem append_empty {xs : Array α} : xs ++ #[] = xs := by
-  apply ext'; simp only [toList_append, toList_empty, List.append_nil]
+  apply ext'; simp only [toList_append, List.append_nil]
 
 @[deprecated append_empty (since := "2025-01-13")]
 abbrev append_nil := @append_empty
 
 @[simp, grind =] theorem empty_append {xs : Array α} : #[] ++ xs = xs := by
-  apply ext'; simp only [toList_append, toList_empty, List.nil_append]
+  apply ext'; simp only [toList_append, List.nil_append]
 
 @[deprecated empty_append (since := "2025-01-13")]
 abbrev nil_append := @empty_append

src/Init/Data/Array/Count.lean

@@ -52,6 +52,7 @@ theorem countP_push {a : α} {xs : Array α} : countP p (xs.push a) = countP p x
   rcases xs with ⟨xs⟩
   simp_all
 
+@[grind =]
 theorem countP_singleton {a : α} : countP p #[a] = if p a then 1 else 0 := by
   simp
 
@@ -59,10 +60,12 @@ theorem size_eq_countP_add_countP {xs : Array α} : xs.size = countP p xs + coun
   rcases xs with ⟨xs⟩
   simp [List.length_eq_countP_add_countP (p := p)]
 
+@[grind _=_]
 theorem countP_eq_size_filter {xs : Array α} : countP p xs = (filter p xs).size := by
   rcases xs with ⟨xs⟩
   simp [List.countP_eq_length_filter]
 
+@[grind =]
 theorem countP_eq_size_filter' : countP p = size ∘ filter p := by
   funext xs
   apply countP_eq_size_filter
@@ -71,7 +74,7 @@ theorem countP_le_size : countP p xs ≤ xs.size := by
   simp only [countP_eq_size_filter]
   apply size_filter_le
 
-@[simp] theorem countP_append {xs ys : Array α} : countP p (xs ++ ys) = countP p xs + countP p ys := by
+@[simp, grind =] theorem countP_append {xs ys : Array α} : countP p (xs ++ ys) = countP p xs + countP p ys := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
   simp
@@ -102,6 +105,7 @@ theorem boole_getElem_le_countP {xs : Array α} {i : Nat} (h : i < xs.size) :
   rcases xs with ⟨xs⟩
   simp [List.boole_getElem_le_countP]
 
+@[grind =]
 theorem countP_set {xs : Array α} {i : Nat} {a : α} (h : i < xs.size) :
     (xs.set i a).countP p = xs.countP p - (if p xs[i] then 1 else 0) + (if p a then 1 else 0) := by
   rcases xs with ⟨xs⟩
@@ -146,7 +150,7 @@ theorem countP_flatMap {p : β → Bool} {xs : Array α} {f : α → Array β} :
   rcases xs with ⟨xs⟩
   simp [List.countP_flatMap, Function.comp_def]
 
-@[simp] theorem countP_reverse {xs : Array α} : countP p xs.reverse = countP p xs := by
+@[simp, grind =] theorem countP_reverse {xs : Array α} : countP p xs.reverse = countP p xs := by
   rcases xs with ⟨xs⟩
   simp [List.countP_reverse]
 
@@ -173,7 +177,7 @@ variable [BEq α]
   cases xs
   simp
 
-@[simp] theorem count_empty {a : α} : count a #[] = 0 := rfl
+@[simp, grind =] theorem count_empty {a : α} : count a #[] = 0 := rfl
 
 theorem count_push {a b : α} {xs : Array α} :
     count a (xs.push b) = count a xs + if b == a then 1 else 0 := by
@@ -186,21 +190,28 @@ theorem count_eq_countP' {a : α} : count a = countP (· == a) := by
 
 theorem count_le_size {a : α} {xs : Array α} : count a xs ≤ xs.size := countP_le_size
 
+grind_pattern count_le_size => count a xs
+
+@[grind =]
+theorem count_eq_size_filter {a : α} {xs : Array α} : count a xs = (filter (· == a) xs).size := by
+  simp [count, countP_eq_size_filter]
+
 theorem count_le_count_push {a b : α} {xs : Array α} : count a xs ≤ count a (xs.push b) := by
   simp [count_push]
 
+@[grind =]
 theorem count_singleton {a b : α} : count a #[b] = if b == a then 1 else 0 := by
   simp [count_eq_countP]
 
-@[simp] theorem count_append {a : α} {xs ys : Array α} : count a (xs ++ ys) = count a xs + count a ys :=
+@[simp, grind =] theorem count_append {a : α} {xs ys : Array α} : count a (xs ++ ys) = count a xs + count a ys :=
   countP_append
 
-@[simp] theorem count_flatten {a : α} {xss : Array (Array α)} :
+@[simp, grind =] theorem count_flatten {a : α} {xss : Array (Array α)} :
     count a xss.flatten = (xss.map (count a)).sum := by
   cases xss using array₂_induction
   simp [List.count_flatten, Function.comp_def]
 
-@[simp] theorem count_reverse {a : α} {xs : Array α} : count a xs.reverse = count a xs := by
+@[simp, grind =] theorem count_reverse {a : α} {xs : Array α} : count a xs.reverse = count a xs := by
   rcases xs with ⟨xs⟩
   simp
 
@@ -209,9 +220,10 @@ theorem boole_getElem_le_count {xs : Array α} {i : Nat} {a : α} (h : i < xs.si
   rw [count_eq_countP]
   apply boole_getElem_le_countP (p := (· == a))
 
+@[grind =]
 theorem count_set {xs : Array α} {i : Nat} {a b : α} (h : i < xs.size) :
     (xs.set i a).count b = xs.count b - (if xs[i] == b then 1 else 0) + (if a == b then 1 else 0) := by
-  simp [count_eq_countP, countP_set, h]
+  simp [count_eq_countP, countP_set]
 
 variable [LawfulBEq α]
 
@@ -219,7 +231,7 @@ variable [LawfulBEq α]
   simp [count_push]
 
 @[simp] theorem count_push_of_ne {xs : Array α} (h : b ≠ a) : count a (xs.push b) = count a xs := by
-  simp_all [count_push, h]
+  simp_all [count_push]
 
 theorem count_singleton_self {a : α} : count a #[a] = 1 := by simp
 
@@ -280,17 +292,17 @@ abbrev mkArray_count_eq_of_count_eq_size := @replicate_count_eq_of_count_eq_size
 theorem count_le_count_map [BEq β] [LawfulBEq β] {xs : Array α} {f : α → β} {x : α} :
     count x xs ≤ count (f x) (map f xs) := by
   rcases xs with ⟨xs⟩
-  simp [List.count_le_count_map, countP_map]
+  simp [List.count_le_count_map]
 
 theorem count_filterMap {α} [BEq β] {b : β} {f : α → Option β} {xs : Array α} :
     count b (filterMap f xs) = countP (fun a => f a == some b) xs := by
   rcases xs with ⟨xs⟩
-  simp [List.count_filterMap, countP_filterMap]
+  simp [List.count_filterMap]
 
 theorem count_flatMap {α} [BEq β] {xs : Array α} {f : α → Array β} {x : β} :
     count x (xs.flatMap f) = sum (map (count x ∘ f) xs) := by
   rcases xs with ⟨xs⟩
-  simp [List.count_flatMap, countP_flatMap, Function.comp_def]
+  simp [List.count_flatMap, Function.comp_def]
 
 theorem countP_replace {a b : α} {xs : Array α} {p : α → Bool} :
     (xs.replace a b).countP p =

src/Init/Data/Array/DecidableEq.lean

@@ -23,7 +23,7 @@ private theorem rel_of_isEqvAux
   induction i with
   | zero => contradiction
   | succ i ih =>
-    simp only [Array.isEqvAux, Bool.and_eq_true, decide_eq_true_eq] at heqv
+    simp only [Array.isEqvAux, Bool.and_eq_true] at heqv
     by_cases hj' : j < i
     next =>
       exact ih _ heqv.right hj'

src/Init/Data/Array/Erase.lean

@@ -24,6 +24,7 @@ open Nat
 
 /-! ### eraseP -/
 
+@[grind =]
 theorem eraseP_empty : #[].eraseP p = #[] := by simp
 
 theorem eraseP_of_forall_mem_not {xs : Array α} (h : ∀ a, a ∈ xs → ¬p a) : xs.eraseP p = xs := by
@@ -64,6 +65,7 @@ theorem exists_or_eq_self_of_eraseP (p) (xs : Array α) :
   let ⟨_, ys, zs, _, _, e₁, e₂⟩ := exists_of_eraseP al pa
   rw [e₂]; simp [size_append, e₁]
 
+@[grind =]
 theorem size_eraseP {xs : Array α} : (xs.eraseP p).size = if xs.any p then xs.size - 1 else xs.size := by
   split <;> rename_i h
   · simp only [any_eq_true] at h
@@ -81,11 +83,12 @@ theorem le_size_eraseP {xs : Array α} : xs.size - 1 ≤ (xs.eraseP p).size := b
   rcases xs with ⟨xs⟩
   simpa using List.le_length_eraseP
 
+@[grind →]
 theorem mem_of_mem_eraseP {xs : Array α} : a ∈ xs.eraseP p → a ∈ xs := by
   rcases xs with ⟨xs⟩
   simpa using List.mem_of_mem_eraseP
 
-@[simp] theorem mem_eraseP_of_neg {xs : Array α} (pa : ¬p a) : a ∈ xs.eraseP p ↔ a ∈ xs := by
+@[simp, grind] theorem mem_eraseP_of_neg {xs : Array α} (pa : ¬p a) : a ∈ xs.eraseP p ↔ a ∈ xs := by
   rcases xs with ⟨xs⟩
   simpa using List.mem_eraseP_of_neg pa
 
@@ -93,15 +96,18 @@ theorem mem_of_mem_eraseP {xs : Array α} : a ∈ xs.eraseP p → a ∈ xs := by
   rcases xs with ⟨xs⟩
   simp
 
+@[grind _=_]
 theorem eraseP_map {f : β → α} {xs : Array β} : (xs.map f).eraseP p = (xs.eraseP (p ∘ f)).map f := by
   rcases xs with ⟨xs⟩
   simpa using List.eraseP_map
 
+@[grind =]
 theorem eraseP_filterMap {f : α → Option β} {xs : Array α} :
     (filterMap f xs).eraseP p = filterMap f (xs.eraseP (fun x => match f x with | some y => p y | none => false)) := by
   rcases xs with ⟨xs⟩
   simpa using List.eraseP_filterMap
 
+@[grind =]
 theorem eraseP_filter {f : α → Bool} {xs : Array α} :
     (filter f xs).eraseP p = filter f (xs.eraseP (fun x => p x && f x)) := by
   rcases xs with ⟨xs⟩
@@ -119,6 +125,7 @@ theorem eraseP_append_right {xs : Array α} ys (h : ∀ b ∈ xs, ¬p b) :
   rcases ys with ⟨ys⟩
   simpa using List.eraseP_append_right ys (by simpa using h)
 
+@[grind =]
 theorem eraseP_append {xs : Array α} {ys : Array α} :
     (xs ++ ys).eraseP p = if xs.any p then xs.eraseP p ++ ys else xs ++ ys.eraseP p := by
   rcases xs with ⟨xs⟩
@@ -126,6 +133,7 @@ theorem eraseP_append {xs : Array α} {ys : Array α} :
   simp only [List.append_toArray, List.eraseP_toArray, List.eraseP_append, List.any_toArray]
   split <;> simp
 
+@[grind =]
 theorem eraseP_replicate {n : Nat} {a : α} {p : α → Bool} :
     (replicate n a).eraseP p = if p a then replicate (n - 1) a else replicate n a := by
   simp only [← List.toArray_replicate, List.eraseP_toArray, List.eraseP_replicate]
@@ -165,6 +173,7 @@ theorem eraseP_eq_iff {p} {xs : Array α} :
     · exact Or.inl h
     · exact Or.inr ⟨a, l₁, by simpa using h₁, h₂, ⟨l, by simp⟩⟩
 
+@[grind =]
 theorem eraseP_comm {xs : Array α} (h : ∀ a ∈ xs, ¬ p a ∨ ¬ q a) :
     (xs.eraseP p).eraseP q = (xs.eraseP q).eraseP p := by
   rcases xs with ⟨xs⟩
@@ -197,7 +206,7 @@ theorem erase_eq_eraseP [LawfulBEq α] (a : α) (xs : Array α) : xs.erase a = x
 theorem erase_ne_empty_iff [LawfulBEq α] {xs : Array α} {a : α} :
     xs.erase a ≠ #[] ↔ xs ≠ #[] ∧ xs ≠ #[a] := by
   rcases xs with ⟨xs⟩
-  simp [List.erase_ne_nil_iff]
+  simp
 
 theorem exists_erase_eq [LawfulBEq α] {a : α} {xs : Array α} (h : a ∈ xs) :
     ∃ ys zs, a ∉ ys ∧ xs = ys.push a ++ zs ∧ xs.erase a = ys ++ zs := by
@@ -208,6 +217,7 @@ theorem exists_erase_eq [LawfulBEq α] {a : α} {xs : Array α} (h : a ∈ xs) :
     (xs.erase a).size = xs.size - 1 := by
   rw [erase_eq_eraseP]; exact size_eraseP_of_mem h (beq_self_eq_true a)
 
+@[grind =]
 theorem size_erase [LawfulBEq α] {a : α} {xs : Array α} :
     (xs.erase a).size = if a ∈ xs then xs.size - 1 else xs.size := by
   rw [erase_eq_eraseP, size_eraseP]
@@ -222,11 +232,12 @@ theorem le_size_erase [LawfulBEq α] {a : α} {xs : Array α} : xs.size - 1 ≤
   rcases xs with ⟨xs⟩
   simpa using List.le_length_erase
 
+@[grind →]
 theorem mem_of_mem_erase {a b : α} {xs : Array α} (h : a ∈ xs.erase b) : a ∈ xs := by
   rcases xs with ⟨xs⟩
   simpa using List.mem_of_mem_erase (by simpa using h)
 
-@[simp] theorem mem_erase_of_ne [LawfulBEq α] {a b : α} {xs : Array α} (ab : a ≠ b) :
+@[simp, grind] theorem mem_erase_of_ne [LawfulBEq α] {a b : α} {xs : Array α} (ab : a ≠ b) :
     a ∈ xs.erase b ↔ a ∈ xs :=
   erase_eq_eraseP b xs ▸ mem_eraseP_of_neg (mt eq_of_beq ab.symm)
 
@@ -234,6 +245,7 @@ theorem mem_of_mem_erase {a b : α} {xs : Array α} (h : a ∈ xs.erase b) : a
   rw [erase_eq_eraseP', eraseP_eq_self_iff]
   simp [forall_mem_ne']
 
+@[grind _=_]
 theorem erase_filter [LawfulBEq α] {f : α → Bool} {xs : Array α} :
     (filter f xs).erase a = filter f (xs.erase a) := by
   rcases xs with ⟨xs⟩
@@ -251,6 +263,7 @@ theorem erase_append_right [LawfulBEq α] {a : α} {xs : Array α} (ys : Array
   rcases ys with ⟨ys⟩
   simpa using List.erase_append_right ys (by simpa using h)
 
+@[grind =]
 theorem erase_append [LawfulBEq α] {a : α} {xs ys : Array α} :
     (xs ++ ys).erase a = if a ∈ xs then xs.erase a ++ ys else xs ++ ys.erase a := by
   rcases xs with ⟨xs⟩
@@ -258,6 +271,7 @@ theorem erase_append [LawfulBEq α] {a : α} {xs ys : Array α} :
   simp only [List.append_toArray, List.erase_toArray, List.erase_append, mem_toArray]
   split <;> simp
 
+@[grind =]
 theorem erase_replicate [LawfulBEq α] {n : Nat} {a b : α} :
     (replicate n a).erase b = if b == a then replicate (n - 1) a else replicate n a := by
   simp only [← List.toArray_replicate, List.erase_toArray]
@@ -269,6 +283,7 @@ abbrev erase_mkArray := @erase_replicate
 
 -- The arguments `a b` are explicit,
 -- so they can be specified to prevent `simp` repeatedly applying the lemma.
+@[grind =]
 theorem erase_comm [LawfulBEq α] (a b : α) {xs : Array α} :
     (xs.erase a).erase b = (xs.erase b).erase a := by
   rcases xs with ⟨xs⟩
@@ -291,7 +306,7 @@ theorem erase_eq_iff [LawfulBEq α] {a : α} {xs : Array α} :
 @[simp] theorem erase_replicate_self [LawfulBEq α] {a : α} :
     (replicate n a).erase a = replicate (n - 1) a := by
   simp only [← List.toArray_replicate, List.erase_toArray]
-  simp [List.erase_replicate]
+  simp
 
 @[deprecated erase_replicate_self (since := "2025-03-18")]
 abbrev erase_mkArray_self := @erase_replicate_self
@@ -312,6 +327,7 @@ theorem eraseIdx_eq_eraseIdxIfInBounds {xs : Array α} {i : Nat} (h : i < xs.siz
     xs.eraseIdx i h = xs.eraseIdxIfInBounds i := by
   simp [eraseIdxIfInBounds, h]
 
+@[grind =]
 theorem eraseIdx_eq_take_drop_succ {xs : Array α} {i : Nat} (h) :
     xs.eraseIdx i h = xs.take i ++ xs.drop (i + 1) := by
   rcases xs with ⟨xs⟩
@@ -322,6 +338,7 @@ theorem eraseIdx_eq_take_drop_succ {xs : Array α} {i : Nat} (h) :
   rw [List.take_of_length_le]
   simp
 
+@[grind =]
 theorem getElem?_eraseIdx {xs : Array α} {i : Nat} (h : i < xs.size) {j : Nat} :
     (xs.eraseIdx i)[j]? = if j < i then xs[j]? else xs[j + 1]? := by
   rcases xs with ⟨xs⟩
@@ -335,10 +352,11 @@ theorem getElem?_eraseIdx_of_lt {xs : Array α} {i : Nat} (h : i < xs.size) {j :
 theorem getElem?_eraseIdx_of_ge {xs : Array α} {i : Nat} (h : i < xs.size) {j : Nat} (h' : i ≤ j) :
     (xs.eraseIdx i)[j]? = xs[j + 1]? := by
   rw [getElem?_eraseIdx]
-  simp only [dite_eq_ite, ite_eq_right_iff]
+  simp only [ite_eq_right_iff]
   intro h'
   omega
 
+@[grind =]
 theorem getElem_eraseIdx {xs : Array α} {i : Nat} (h : i < xs.size) {j : Nat} (h' : j < (xs.eraseIdx i).size) :
     (xs.eraseIdx i)[j] = if h'' : j < i then
         xs[j]
@@ -362,6 +380,7 @@ theorem eraseIdx_ne_empty_iff {xs : Array α} {i : Nat} {h} : xs.eraseIdx i ≠
     simp [h]
   · simp
 
+@[grind →]
 theorem mem_of_mem_eraseIdx {xs : Array α} {i : Nat} {h} {a : α} (h : a ∈ xs.eraseIdx i) : a ∈ xs := by
   rcases xs with ⟨xs⟩
   simpa using List.mem_of_mem_eraseIdx (by simpa using h)
@@ -373,13 +392,29 @@ theorem eraseIdx_append_of_lt_size {xs : Array α} {k : Nat} (hk : k < xs.size)
   simp at hk
   simp [List.eraseIdx_append_of_lt_length, *]
 
-theorem eraseIdx_append_of_length_le {xs : Array α} {k : Nat} (hk : xs.size ≤ k) (ys : Array α) (h) :
+theorem eraseIdx_append_of_size_le {xs : Array α} {k : Nat} (hk : xs.size ≤ k) (ys : Array α) (h) :
     eraseIdx (xs ++ ys) k = xs ++ eraseIdx ys (k - xs.size) (by simp at h; omega) := by
   rcases xs with ⟨l⟩
   rcases ys with ⟨l'⟩
   simp at hk
   simp [List.eraseIdx_append_of_length_le, *]
 
+@[deprecated eraseIdx_append_of_size_le (since := "2025-06-11")]
+abbrev eraseIdx_append_of_length_le := @eraseIdx_append_of_size_le
+
+@[grind =]
+theorem eraseIdx_append {xs ys : Array α} (h : k < (xs ++ ys).size) :
+    eraseIdx (xs ++ ys) k =
+      if h' : k < xs.size then
+        eraseIdx xs k ++ ys
+      else
+        xs ++ eraseIdx ys (k - xs.size) (by simp at h; omega) := by
+  split <;> rename_i h
+  · simp [eraseIdx_append_of_lt_size h]
+  · rw [eraseIdx_append_of_size_le]
+    omega
+
+@[grind =]
 theorem eraseIdx_replicate {n : Nat} {a : α} {k : Nat} {h} :
     (replicate n a).eraseIdx k = replicate (n - 1) a := by
   simp at h
@@ -428,6 +463,48 @@ theorem eraseIdx_set_gt {xs : Array α} {i : Nat} {j : Nat} {a : α} (h : i < j)
   rcases xs with ⟨xs⟩
   simp [List.eraseIdx_set_gt, *]
 
+@[grind =]
+theorem eraseIdx_set {xs : Array α} {i : Nat} {a : α} {hi : i < xs.size} {j : Nat} {hj : j < (xs.set i a).size} :
+    (xs.set i a).eraseIdx j =
+      if h' : j < i then
+        (xs.eraseIdx j).set (i - 1) a (by simp; omega)
+      else if h'' : j = i then
+        xs.eraseIdx i
+      else
+        (xs.eraseIdx j (by simp at hj; omega)).set i a (by simp at hj ⊢; omega) := by
+  split <;> rename_i h'
+  · rw [eraseIdx_set_lt]
+    omega
+  · split <;> rename_i h''
+    · subst h''
+      rw [eraseIdx_set_eq]
+    · rw [eraseIdx_set_gt]
+      omega
+
+theorem set_eraseIdx_le {xs : Array α} {i : Nat} {w : i < xs.size} {j : Nat} {a : α} (h : i ≤ j) (hj : j < (xs.eraseIdx i).size) :
+    (xs.eraseIdx i).set j a = (xs.set (j + 1) a (by simp at hj; omega)).eraseIdx i (by simp at ⊢; omega) := by
+  rw [eraseIdx_set_lt]
+  · simp
+  · omega
+
+theorem set_eraseIdx_gt {xs : Array α} {i : Nat} {w : i < xs.size} {j : Nat} {a : α} (h : j < i) (hj : j < (xs.eraseIdx i).size) :
+    (xs.eraseIdx i).set j a = (xs.set j a).eraseIdx i (by simp at ⊢; omega) := by
+  rw [eraseIdx_set_gt]
+  omega
+
+@[grind =]
+theorem set_eraseIdx {xs : Array α} {i : Nat} {w : i < xs.size} {j : Nat} {a : α} (hj : j < (xs.eraseIdx i).size) :
+    (xs.eraseIdx i).set j a =
+      if h' : i ≤ j then
+        (xs.set (j + 1) a (by simp at hj; omega)).eraseIdx i (by simp at ⊢; omega)
+      else
+        (xs.set j a).eraseIdx i (by simp at ⊢; omega) := by
+  split <;> rename_i h'
+  · rw [set_eraseIdx_le]
+    omega
+  · rw [set_eraseIdx_gt]
+    omega
+
 @[simp] theorem set_getElem_succ_eraseIdx_succ
     {xs : Array α} {i : Nat} (h : i + 1 < xs.size) :
     (xs.eraseIdx (i + 1)).set i xs[i + 1] (by simp; omega) = xs.eraseIdx i := by

src/Init/Data/Array/Extract.lean

@@ -29,7 +29,7 @@ namespace Array
   · simp
     omega
   · simp only [size_extract] at h₁ h₂
-    simp [h]
+    simp
 
 theorem size_extract_le {as : Array α} {i j : Nat} :
     (as.extract i j).size ≤ j - i := by
@@ -46,7 +46,7 @@ theorem size_extract_of_le {as : Array α} {i j : Nat} (h : j ≤ as.size) :
   simp
   omega
 
-@[simp]
+@[simp, grind =]
 theorem extract_push {as : Array α} {b : α} {start stop : Nat} (h : stop ≤ as.size) :
     (as.push b).extract start stop = as.extract start stop := by
   ext i h₁ h₂
@@ -56,7 +56,7 @@ theorem extract_push {as : Array α} {b : α} {start stop : Nat} (h : stop ≤ a
     simp only [getElem_extract, getElem_push]
     rw [dif_pos (by omega)]
 
-@[simp]
+@[simp, grind =]
 theorem extract_eq_pop {as : Array α} {stop : Nat} (h : stop = as.size - 1) :
     as.extract 0 stop = as.pop := by
   ext i h₁ h₂
@@ -65,7 +65,7 @@ theorem extract_eq_pop {as : Array α} {stop : Nat} (h : stop = as.size - 1) :
   · simp only [size_extract, size_pop] at h₁ h₂
     simp [getElem_extract, getElem_pop]
 
-@[simp]
+@[simp, grind _=_]
 theorem extract_append_extract {as : Array α} {i j k : Nat} :
     as.extract i j ++ as.extract j k = as.extract (min i j) (max j k) := by
   ext l h₁ h₂
@@ -162,14 +162,14 @@ theorem extract_sub_one {as : Array α} {i j : Nat} (h : j < as.size) :
 @[simp]
 theorem getElem?_extract_of_lt {as : Array α} {i j k : Nat} (h : k < min j as.size - i) :
     (as.extract i j)[k]? = some (as[i + k]'(by omega)) := by
-  simp [getElem?_extract, h]
+  simp [h]
 
 theorem getElem?_extract_of_succ {as : Array α} {j : Nat} :
     (as.extract 0 (j + 1))[j]? = as[j]? := by
   simp [getElem?_extract]
   omega
 
-@[simp] theorem extract_extract {as : Array α} {i j k l : Nat} :
+@[simp, grind =] theorem extract_extract {as : Array α} {i j k l : Nat} :
     (as.extract i j).extract k l = as.extract (i + k) (min (i + l) j) := by
   ext m h₁ h₂
   · simp
@@ -185,6 +185,7 @@ theorem ne_empty_of_extract_ne_empty {as : Array α} {i j : Nat} (h : as.extract
     as ≠ #[] :=
   mt extract_eq_empty_of_eq_empty h
 
+@[grind =]
 theorem extract_set {as : Array α} {i j k : Nat} (h : k < as.size) {a : α} :
     (as.set k a).extract i j =
       if _ : k < i then
@@ -211,13 +212,14 @@ theorem extract_set {as : Array α} {i j k : Nat} (h : k < as.size) {a : α} :
         simp [getElem_set]
         omega
 
+@[grind =]
 theorem set_extract {as : Array α} {i j k : Nat} (h : k < (as.extract i j).size) {a : α} :
     (as.extract i j).set k a = (as.set (i + k) a (by simp at h; omega)).extract i j := by
   ext l h₁ h₂
   · simp
   · simp_all [getElem_set]
 
-@[simp]
+@[simp, grind =]
 theorem extract_append {as bs : Array α} {i j : Nat} :
     (as ++ bs).extract i j = as.extract i j ++ bs.extract (i - as.size) (j - as.size) := by
   ext l h₁ h₂
@@ -242,14 +244,14 @@ theorem extract_append_right {as bs : Array α} :
     (as ++ bs).extract as.size (as.size + i) = bs.extract 0 i := by
   simp
 
-@[simp] theorem map_extract {as : Array α} {i j : Nat} :
+@[simp, grind =] theorem map_extract {as : Array α} {i j : Nat} :
     (as.extract i j).map f = (as.map f).extract i j := by
   ext l h₁ h₂
   · simp
   · simp only [size_map, size_extract] at h₁ h₂
     simp only [getElem_map, getElem_extract]
 
-@[simp] theorem extract_replicate {a : α} {n i j : Nat} :
+@[simp, grind =] theorem extract_replicate {a : α} {n i j : Nat} :
     (replicate n a).extract i j = replicate (min j n - i) a := by
   ext l h₁ h₂
   · simp
@@ -297,6 +299,7 @@ theorem set_eq_push_extract_append_extract {as : Array α} {i : Nat} (h : i < as
   simp at h
   simp [List.set_eq_take_append_cons_drop, h, List.take_of_length_le]
 
+@[grind =]
 theorem extract_reverse {as : Array α} {i j : Nat} :
     as.reverse.extract i j = (as.extract (as.size - j) (as.size - i)).reverse := by
   ext l h₁ h₂
@@ -307,6 +310,7 @@ theorem extract_reverse {as : Array α} {i j : Nat} :
     congr 1
     omega
 
+@[grind =]
 theorem reverse_extract {as : Array α} {i j : Nat} :
     (as.extract i j).reverse = as.reverse.extract (as.size - j) (as.size - i) := by
   rw [extract_reverse]

src/Init/Data/Array/FinRange.lean

@@ -23,10 +23,10 @@ Examples:
 -/
 protected def finRange (n : Nat) : Array (Fin n) := ofFn fun i => i
 
-@[simp] theorem size_finRange {n} : (Array.finRange n).size = n := by
+@[simp, grind =] theorem size_finRange {n} : (Array.finRange n).size = n := by
   simp [Array.finRange]
 
-@[simp] theorem getElem_finRange {i : Nat} (h : i < (Array.finRange n).size) :
+@[simp, grind =] theorem getElem_finRange {i : Nat} (h : i < (Array.finRange n).size) :
     (Array.finRange n)[i] = Fin.cast size_finRange ⟨i, h⟩ := by
   simp [Array.finRange]
 
@@ -49,6 +49,7 @@ theorem finRange_succ_last {n} :
     · simp_all
       omega
 
+@[grind _=_]
 theorem finRange_reverse {n} : (Array.finRange n).reverse = (Array.finRange n).map Fin.rev := by
   ext i h
   · simp

src/Init/Data/Array/Find.lean

@@ -38,11 +38,22 @@ theorem findSome?_singleton {a : α} {f : α → Option β} : #[a].findSome? f =
 @[simp] theorem findSomeRev?_push_of_isNone {xs : Array α} (h : (f a).isNone) : (xs.push a).findSomeRev? f = xs.findSomeRev? f := by
   cases xs; simp_all
 
+@[grind =]
+theorem findSomeRev?_push {xs : Array α} {a : α} {f : α → Option β} :
+    (xs.push a).findSomeRev? f = (f a).or (xs.findSomeRev? f) := by
+  match h : f a with
+  | some b =>
+    rw [findSomeRev?_push_of_isSome]
+    all_goals simp_all
+  | none =>
+    rw [findSomeRev?_push_of_isNone]
+    all_goals simp_all
+
 theorem exists_of_findSome?_eq_some {f : α → Option β} {xs : Array α} (w : xs.findSome? f = some b) :
     ∃ a, a ∈ xs ∧ f a = some b := by
   cases xs; simp_all [List.exists_of_findSome?_eq_some]
 
-@[simp] theorem findSome?_eq_none_iff : findSome? p xs = none ↔ ∀ x ∈ xs, p x = none := by
+@[simp, grind =] theorem findSome?_eq_none_iff : findSome? p xs = none ↔ ∀ x ∈ xs, p x = none := by
   cases xs; simp
 
 @[simp] theorem findSome?_isSome_iff {f : α → Option β} {xs : Array α} :
@@ -59,36 +70,39 @@ theorem findSome?_eq_some_iff {f : α → Option β} {xs : Array α} {b : β} :
   · rintro ⟨xs, a, ys, h₀, h₁, h₂⟩
     exact ⟨xs.toList, a, ys.toList, by simpa using congrArg toList h₀, h₁, by simpa⟩
 
-@[simp] theorem findSome?_guard {xs : Array α} : findSome? (Option.guard fun x => p x) xs = find? p xs := by
+@[simp, grind =] theorem findSome?_guard {xs : Array α} : findSome? (Option.guard p) xs = find? p xs := by
   cases xs; simp
 
-theorem find?_eq_findSome?_guard {xs : Array α} : find? p xs = findSome? (Option.guard fun x => p x) xs :=
+theorem find?_eq_findSome?_guard {xs : Array α} : find? p xs = findSome? (Option.guard p) xs :=
   findSome?_guard.symm
 
-@[simp] theorem getElem?_zero_filterMap {f : α → Option β} {xs : Array α} : (xs.filterMap f)[0]? = xs.findSome? f := by
+@[simp, grind =] theorem getElem?_zero_filterMap {f : α → Option β} {xs : Array α} : (xs.filterMap f)[0]? = xs.findSome? f := by
   cases xs; simp [← List.head?_eq_getElem?]
 
-@[simp] theorem getElem_zero_filterMap {f : α → Option β} {xs : Array α} (h) :
+@[simp, grind =] theorem getElem_zero_filterMap {f : α → Option β} {xs : Array α} (h) :
     (xs.filterMap f)[0] = (xs.findSome? f).get (by cases xs; simpa [List.length_filterMap_eq_countP] using h) := by
-  cases xs; simp [← List.head_eq_getElem, ← getElem?_zero_filterMap]
+  cases xs; simp [← getElem?_zero_filterMap]
 
-@[simp] theorem back?_filterMap {f : α → Option β} {xs : Array α} : (xs.filterMap f).back? = xs.findSomeRev? f := by
+@[simp, grind =] theorem back?_filterMap {f : α → Option β} {xs : Array α} : (xs.filterMap f).back? = xs.findSomeRev? f := by
   cases xs; simp
 
-@[simp] theorem back!_filterMap [Inhabited β] {f : α → Option β} {xs : Array α} :
+@[simp, grind =] theorem back!_filterMap [Inhabited β] {f : α → Option β} {xs : Array α} :
     (xs.filterMap f).back! = (xs.findSomeRev? f).getD default := by
   cases xs; simp
 
-@[simp] theorem map_findSome? {f : α → Option β} {g : β → γ} {xs : Array α} :
+@[simp, grind _=_] theorem map_findSome? {f : α → Option β} {g : β → γ} {xs : Array α} :
     (xs.findSome? f).map g = xs.findSome? (Option.map g ∘ f) := by
   cases xs; simp
 
+@[grind _=_]
 theorem findSome?_map {f : β → γ} {xs : Array β} : findSome? p (xs.map f) = xs.findSome? (p ∘ f) := by
   cases xs; simp [List.findSome?_map]
 
+@[grind =]
 theorem findSome?_append {xs ys : Array α} : (xs ++ ys).findSome? f = (xs.findSome? f).or (ys.findSome? f) := by
   cases xs; cases ys; simp [List.findSome?_append]
 
+@[grind =]
 theorem getElem?_zero_flatten (xss : Array (Array α)) :
     (flatten xss)[0]? = xss.findSome? fun xs => xs[0]? := by
   cases xss using array₂_induction
@@ -104,12 +118,14 @@ theorem getElem_zero_flatten.proof {xss : Array (Array α)} (h : 0 < xss.flatten
   obtain ⟨_, ⟨xs, m, rfl⟩, h⟩ := h
   exact ⟨xs, m, by simpa using h⟩
 
+@[grind =]
 theorem getElem_zero_flatten {xss : Array (Array α)} (h) :
     (flatten xss)[0] = (xss.findSome? fun xs => xs[0]?).get (getElem_zero_flatten.proof h) := by
   have t := getElem?_zero_flatten xss
-  simp [getElem?_eq_getElem, h] at t
+  simp at t
   simp [← t]
 
+@[grind =]
 theorem findSome?_replicate : findSome? f (replicate n a) = if n = 0 then none else f a := by
   simp [← List.toArray_replicate, List.findSome?_replicate]
 
@@ -140,8 +156,9 @@ abbrev findSome?_mkArray_of_isNone := @findSome?_replicate_of_isNone
 
 /-! ### find? -/
 
-@[simp] theorem find?_empty : find? p #[] = none := rfl
+@[simp, grind =] theorem find?_empty : find? p #[] = none := rfl
 
+@[grind =]
 theorem find?_singleton {a : α} {p : α → Bool} :
     #[a].find? p = if p a then some a else none := by
   simp
@@ -150,11 +167,26 @@ theorem find?_singleton {a : α} {p : α → Bool} :
     findRev? p (xs.push a) = some a := by
   cases xs; simp [h]
 
-@[simp] theorem findRev?_cons_of_neg {xs : Array α} (h : ¬p a) :
+@[simp] theorem findRev?_push_of_neg {xs : Array α} (h : ¬p a) :
     findRev? p (xs.push a) = findRev? p xs := by
   cases xs; simp [h]
 
-@[simp] theorem find?_eq_none : find? p xs = none ↔ ∀ x ∈ xs, ¬ p x := by
+@[deprecated findRev?_push_of_neg (since := "2025-06-12")]
+abbrev findRev?_cons_of_neg := @findRev?_push_of_neg
+
+@[grind =]
+theorem finRev?_push {xs : Array α} :
+    findRev? p (xs.push a) = (Option.guard p a).or (xs.findRev? p) := by
+  cases h : p a
+  · rw [findRev?_push_of_neg, Option.guard_eq_none_iff.mpr h]
+    all_goals simp [h]
+  · rw [findRev?_push_of_pos, Option.guard_eq_some_iff.mpr ⟨rfl, h⟩]
+    all_goals simp [h]
+
+@[deprecated finRev?_push (since := "2025-06-12")]
+abbrev findRev?_cons := @finRev?_push
+
+@[simp, grind =] theorem find?_eq_none : find? p xs = none ↔ ∀ x ∈ xs, ¬ p x := by
   cases xs; simp
 
 theorem find?_eq_some_iff_append {xs : Array α} :
@@ -178,60 +210,63 @@ 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
+@[simp, grind =] theorem find?_isSome {xs : Array α} {p : α → Bool} : (xs.find? p).isSome ↔ ∃ x, x ∈ xs ∧ p x := by
   cases xs; simp
 
+@[grind →]
 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
 
+@[grind →]
 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
 
+@[grind]
 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) :
+@[simp, grind =] 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} {xs : Array α} :
+@[simp, grind =] theorem getElem?_zero_filter {p : α → Bool} {xs : Array α} :
     (xs.filter p)[0]? = xs.find? p := by
   cases xs; simp [← List.head?_eq_getElem?]
 
-@[simp] theorem getElem_zero_filter {p : α → Bool} {xs : Array α} (h) :
+@[simp, grind =] theorem getElem_zero_filter {p : α → Bool} {xs : Array α} (h) :
     (xs.filter p)[0] =
       (xs.find? p).get (by cases xs; simpa [← List.countP_eq_length_filter] using h) := by
   cases xs
   simp [List.getElem_zero_eq_head]
 
-@[simp] theorem back?_filter {p : α → Bool} {xs : Array α} : (xs.filter p).back? = xs.findRev? p := by
+@[simp, grind =] theorem back?_filter {p : α → Bool} {xs : Array α} : (xs.filter p).back? = xs.findRev? p := by
   cases xs; simp
 
-@[simp] theorem back!_filter [Inhabited α] {p : α → Bool} {xs : Array α} :
+@[simp, grind =] theorem back!_filter [Inhabited α] {p : α → Bool} {xs : Array α} :
     (xs.filter p).back! = (xs.findRev? p).get! := by
   cases xs; simp [Option.get!_eq_getD]
 
-@[simp] theorem find?_filterMap {xs : Array α} {f : α → Option β} {p : β → Bool} :
+@[simp, grind =] 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} :
+@[simp, grind =] 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 {xs ys : Array α} :
+@[simp, grind =] theorem find?_append {xs ys : Array α} :
     (xs ++ ys).find? p = (xs.find? p).or (ys.find? p) := by
   cases xs
   cases ys
   simp
 
-@[simp] theorem find?_flatten {xss : Array (Array α)} {p : α → Bool} :
-    xss.flatten.find? p = xss.findSome? (·.find? p) := by
+@[simp, grind _=_] theorem find?_flatten {xss : Array (Array α)} {p : α → Bool} :
+    xss.flatten.find? p = xss.findSome? (find? p) := by
   cases xss using array₂_induction
   simp [List.findSome?_map, Function.comp_def]
 
@@ -270,10 +305,10 @@ theorem find?_flatten_eq_some_iff {xss : Array (Array α)} {p : α → Bool} {a
 @[deprecated find?_flatten_eq_some_iff (since := "2025-02-03")]
 abbrev find?_flatten_eq_some := @find?_flatten_eq_some_iff
 
-@[simp] theorem find?_flatMap {xs : Array α} {f : α → Array β} {p : β → Bool} :
+@[simp, grind =] 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]
+  simp [List.find?_flatMap]
 
 theorem find?_flatMap_eq_none_iff {xs : Array α} {f : α → Array β} {p : β → Bool} :
     (xs.flatMap f).find? p = none ↔ ∀ x ∈ xs, ∀ y ∈ f x, !p y := by
@@ -282,6 +317,7 @@ theorem find?_flatMap_eq_none_iff {xs : Array α} {f : α → Array β} {p : β
 @[deprecated find?_flatMap_eq_none_iff (since := "2025-02-03")]
 abbrev find?_flatMap_eq_none := @find?_flatMap_eq_none_iff
 
+@[grind =]
 theorem find?_replicate :
     find? p (replicate n a) = if n = 0 then none else if p a then some a else none := by
   simp [← List.toArray_replicate, List.find?_replicate]
@@ -312,7 +348,7 @@ abbrev find?_mkArray_of_neg := @find?_replicate_of_neg
 -- This isn't a `@[simp]` lemma since there is already a lemma for `l.find? p = none` for any `l`.
 theorem find?_replicate_eq_none_iff {n : Nat} {a : α} {p : α → Bool} :
     (replicate n a).find? p = none ↔ n = 0 ∨ !p a := by
-  simp [← List.toArray_replicate, List.find?_replicate_eq_none_iff, Classical.or_iff_not_imp_left]
+  simp [← List.toArray_replicate, Classical.or_iff_not_imp_left]
 
 @[deprecated find?_replicate_eq_none_iff (since := "2025-03-18")]
 abbrev find?_mkArray_eq_none_iff := @find?_replicate_eq_none_iff
@@ -334,6 +370,7 @@ abbrev find?_mkArray_eq_some := @find?_replicate_eq_some_iff
 @[deprecated get_find?_replicate (since := "2025-03-18")]
 abbrev get_find?_mkArray := @get_find?_replicate
 
+@[grind =]
 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
@@ -347,12 +384,15 @@ theorem find?_eq_some_iff_getElem {xs : Array α} {p : α → Bool} {b : α} :
 
 /-! ### findIdx -/
 
+@[grind =]
 theorem findIdx_empty : findIdx p #[] = 0 := rfl
 
+@[grind =]
 theorem findIdx_singleton {a : α} {p : α → Bool} :
     #[a].findIdx p = if p a then 0 else 1 := by
   simp
 
+@[grind →]
 theorem findIdx_of_getElem?_eq_some {xs : Array α} (w : xs[xs.findIdx p]? = some y) : p y := by
   rcases xs with ⟨xs⟩
   exact List.findIdx_of_getElem?_eq_some (by simpa using w)
@@ -361,6 +401,8 @@ theorem findIdx_getElem {xs : Array α} {w : xs.findIdx p < xs.size} :
     p xs[xs.findIdx p] :=
   xs.findIdx_of_getElem?_eq_some (getElem?_eq_getElem w)
 
+grind_pattern findIdx_getElem => xs[xs.findIdx p]
+
 theorem findIdx_lt_size_of_exists {xs : Array α} (h : ∃ x ∈ xs, p x) :
     xs.findIdx p < xs.size := by
   rcases xs with ⟨xs⟩
@@ -387,18 +429,24 @@ theorem findIdx_le_size {p : α → Bool} {xs : Array α} : xs.findIdx p ≤ xs.
   · simp at e
     exact Nat.le_of_eq (findIdx_eq_size.mpr e)
 
+grind_pattern findIdx_le_size => xs.findIdx p, xs.size
+
 @[simp]
 theorem findIdx_lt_size {p : α → Bool} {xs : Array α} :
     xs.findIdx p < xs.size ↔ ∃ x ∈ xs, p x := by
   rcases xs with ⟨xs⟩
   simp
 
+grind_pattern findIdx_lt_size => xs.findIdx p, xs.size
+
 /-- `p` does not hold for elements with indices less than `xs.findIdx p`. -/
 theorem not_of_lt_findIdx {p : α → Bool} {xs : Array α} {i : Nat} (h : i < xs.findIdx p) :
     p (xs[i]'(Nat.le_trans h findIdx_le_size)) = false := by
   rcases xs with ⟨xs⟩
   simpa using List.not_of_lt_findIdx (by simpa using h)
 
+grind_pattern not_of_lt_findIdx => xs.findIdx p, xs[i]
+
 /-- If `¬ p xs[j]` for all `j < i`, then `i ≤ xs.findIdx p`. -/
 theorem le_findIdx_of_not {p : α → Bool} {xs : Array α} {i : Nat} (h : i < xs.size)
     (h2 : ∀ j (hji : j < i), p (xs[j]'(Nat.lt_trans hji h)) = false) : i ≤ xs.findIdx p := by
@@ -426,6 +474,7 @@ theorem findIdx_eq {p : α → Bool} {xs : Array α} {i : Nat} (h : i < xs.size)
   simp at h3
   simp_all [not_of_lt_findIdx h3]
 
+@[grind =]
 theorem findIdx_append {p : α → Bool} {xs ys : Array α} :
     (xs ++ ys).findIdx p =
       if xs.findIdx p < xs.size then xs.findIdx p else ys.findIdx p + xs.size := by
@@ -433,12 +482,13 @@ theorem findIdx_append {p : α → Bool} {xs ys : Array α} :
   rcases ys with ⟨ys⟩
   simp [List.findIdx_append]
 
+@[grind =]
 theorem findIdx_push {xs : Array α} {a : α} {p : α → Bool} :
     (xs.push a).findIdx p = if xs.findIdx p < xs.size then xs.findIdx p else xs.size + if p a then 0 else 1 := by
   simp only [push_eq_append, findIdx_append]
   split <;> rename_i h
   · rfl
-  · simp [findIdx_singleton, Nat.add_comm]
+  · simp [Nat.add_comm]
 
 theorem findIdx_le_findIdx {xs : Array α} {p q : α → Bool} (h : ∀ x ∈ xs, p x → q x) : xs.findIdx q ≤ xs.findIdx p := by
   rcases xs with ⟨xs⟩
@@ -455,7 +505,7 @@ theorem false_of_mem_extract_findIdx {xs : Array α} {p : α → Bool} (h : x
   rcases xs with ⟨xs⟩
   exact List.false_of_mem_take_findIdx (by simpa using h)
 
-@[simp] theorem findIdx_extract {xs : Array α} {i : Nat} {p : α → Bool} :
+@[simp, grind =] theorem findIdx_extract {xs : Array α} {i : Nat} {p : α → Bool} :
     (xs.extract 0 i).findIdx p = min i (xs.findIdx p) := by
   cases xs
   simp
@@ -467,24 +517,24 @@ theorem false_of_mem_extract_findIdx {xs : Array α} {p : α → Bool} (h : x
 
 /-! ### findIdx? -/
 
-@[simp] theorem findIdx?_empty : (#[] : Array α).findIdx? p = none := by simp
-theorem findIdx?_singleton {a : α} {p : α → Bool} :
+@[simp, grind =] theorem findIdx?_empty : (#[] : Array α).findIdx? p = none := by simp
+@[grind =] theorem findIdx?_singleton {a : α} {p : α → Bool} :
     #[a].findIdx? p = if p a then some 0 else none := by
   simp
 
-@[simp]
+@[simp, grind =]
 theorem findIdx?_eq_none_iff {xs : Array α} {p : α → Bool} :
     xs.findIdx? p = none ↔ ∀ x, x ∈ xs → p x = false := by
   rcases xs with ⟨xs⟩
   simp
 
-@[simp]
+@[simp, grind =]
 theorem findIdx?_isSome {xs : Array α} {p : α → Bool} :
     (xs.findIdx? p).isSome = xs.any p := by
   rcases xs with ⟨xs⟩
   simp [List.findIdx?_isSome]
 
-@[simp]
+@[simp, grind =]
 theorem findIdx?_isNone {xs : Array α} {p : α → Bool} :
     (xs.findIdx? p).isNone = xs.all (¬p ·) := by
   rcases xs with ⟨xs⟩
@@ -503,7 +553,7 @@ theorem findIdx?_eq_some_of_exists {xs : Array α} {p : α → Bool} (h : ∃ x,
 theorem findIdx?_eq_none_iff_findIdx_eq {xs : Array α} {p : α → Bool} :
     xs.findIdx? p = none ↔ xs.findIdx p = xs.size := by
   rcases xs with ⟨xs⟩
-  simp [List.findIdx?_eq_none_iff_findIdx_eq]
+  simp
 
 theorem findIdx?_eq_guard_findIdx_lt {xs : Array α} {p : α → Bool} :
     xs.findIdx? p = Option.guard (fun i => i < xs.size) (xs.findIdx p) := by
@@ -526,18 +576,19 @@ theorem of_findIdx?_eq_none {xs : Array α} {p : α → Bool} (w : xs.findIdx? p
   rcases xs with ⟨xs⟩
   simpa using List.of_findIdx?_eq_none (by simpa using w)
 
-@[simp] theorem findIdx?_map {f : β → α} {xs : Array β} {p : α → Bool} :
+@[simp, grind =] theorem findIdx?_map {f : β → α} {xs : Array β} {p : α → Bool} :
     findIdx? p (xs.map f) = xs.findIdx? (p ∘ f) := by
   rcases xs with ⟨xs⟩
   simp [List.findIdx?_map]
 
-@[simp] theorem findIdx?_append :
+@[simp, grind =] theorem findIdx?_append :
     (xs ++ ys : Array α).findIdx? p =
       (xs.findIdx? p).or ((ys.findIdx? p).map fun i => i + xs.size) := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
   simp [List.findIdx?_append]
 
+@[grind =]
 theorem findIdx?_push {xs : Array α} {a : α} {p : α → Bool} :
     (xs.push a).findIdx? p = (xs.findIdx? p).or (if p a then some xs.size else none) := by
   simp only [push_eq_append, findIdx?_append]
@@ -553,7 +604,7 @@ theorem findIdx?_flatten {xss : Array (Array α)} {p : α → Bool} :
   cases xss using array₂_induction
   simp [List.findIdx?_flatten, Function.comp_def]
 
-@[simp] theorem findIdx?_replicate :
+@[simp, grind =] theorem findIdx?_replicate :
     (replicate n a).findIdx? p = if 0 < n ∧ p a then some 0 else none := by
   rw [← List.toArray_replicate]
   simp only [List.findIdx?_toArray]
@@ -578,6 +629,7 @@ theorem findIdx?_eq_none_of_findIdx?_eq_none {xs : Array α} {p q : α → Bool}
   rcases xs with ⟨xs⟩
   simpa using List.findIdx?_eq_none_of_findIdx?_eq_none (by simpa using w)
 
+@[grind =]
 theorem findIdx_eq_getD_findIdx? {xs : Array α} {p : α → Bool} :
     xs.findIdx p = (xs.findIdx? p).getD xs.size := by
   rcases xs with ⟨xs⟩
@@ -594,15 +646,17 @@ theorem findIdx?_eq_some_le_of_findIdx?_eq_some {xs : Array α} {p q : α → Bo
   cases xs
   simp [hf]
 
-@[simp] theorem findIdx?_take {xs : Array α} {i : Nat} {p : α → Bool} :
+@[simp, grind =] theorem findIdx?_take {xs : Array α} {i : Nat} {p : α → Bool} :
     (xs.take i).findIdx? p = (xs.findIdx? p).bind (Option.guard (fun j => j < i)) := by
   cases xs
   simp
 
 /-! ### findFinIdx? -/
 
+@[grind =]
 theorem findFinIdx?_empty {p : α → Bool} : findFinIdx? p #[] = none := by simp
 
+@[grind =]
 theorem findFinIdx?_singleton {a : α} {p : α → Bool} :
     #[a].findFinIdx? p = if p a then some ⟨0, by simp⟩ else none := by
   simp
@@ -620,7 +674,7 @@ theorem findFinIdx?_eq_pmap_findIdx? {xs : Array α} {p : α → Bool} :
         (fun i h => h) := by
   simp [findIdx?_eq_map_findFinIdx?_val, Option.pmap_map]
 
-@[simp] theorem findFinIdx?_eq_none_iff {xs : Array α} {p : α → Bool} :
+@[simp, grind =] theorem findFinIdx?_eq_none_iff {xs : Array α} {p : α → Bool} :
     xs.findFinIdx? p = none ↔ ∀ x, x ∈ xs → ¬ p x := by
   simp [findFinIdx?_eq_pmap_findIdx?]
 
@@ -636,12 +690,14 @@ theorem findFinIdx?_eq_some_iff {xs : Array α} {p : α → Bool} {i : Fin xs.si
   · rintro ⟨h, w⟩
     exact ⟨i, ⟨i.2, h, fun j hji => w ⟨j, by omega⟩ hji⟩, rfl⟩
 
+@[grind =]
 theorem findFinIdx?_push {xs : Array α} {a : α} {p : α → Bool} :
     (xs.push a).findFinIdx? p =
       ((xs.findFinIdx? p).map (Fin.castLE (by simp))).or (if p a then some ⟨xs.size, by simp⟩ else none) := by
   simp only [findFinIdx?_eq_pmap_findIdx?, findIdx?_push, Option.pmap_or]
   split <;> rename_i h _ <;> split <;> simp [h]
 
+@[grind =]
 theorem findFinIdx?_append {xs ys : Array α} {p : α → Bool} :
     (xs ++ ys).findFinIdx? p =
       ((xs.findFinIdx? p).map (Fin.castLE (by simp))).or
@@ -651,13 +707,13 @@ theorem findFinIdx?_append {xs ys : Array α} {p : α → Bool} :
   · simp [h, Option.pmap_map, Option.map_pmap, Nat.add_comm]
   · simp [h]
 
-@[simp]
+@[simp, grind =]
 theorem isSome_findFinIdx? {xs : Array α} {p : α → Bool} :
     (xs.findFinIdx? p).isSome = xs.any p := by
   rcases xs with ⟨xs⟩
   simp [Array.size]
 
-@[simp]
+@[simp, grind =]
 theorem isNone_findFinIdx? {xs : Array α} {p : α → Bool} :
     (xs.findFinIdx? p).isNone = xs.all (fun x => ¬ p x) := by
   rcases xs with ⟨xs⟩
@@ -678,6 +734,7 @@ The verification API for `idxOf` is still incomplete.
 The lemmas below should be made consistent with those for `findIdx` (and proved using them).
 -/
 
+@[grind =]
 theorem idxOf_append [BEq α] [LawfulBEq α] {xs ys : Array α} {a : α} :
     (xs ++ ys).idxOf a = if a ∈ xs then xs.idxOf a else ys.idxOf a + xs.size := by
   rw [idxOf, findIdx_append]
@@ -691,10 +748,23 @@ theorem idxOf_eq_size [BEq α] [LawfulBEq α] {xs : Array α} (h : a ∉ xs) : x
   rcases xs with ⟨xs⟩
   simp [List.idxOf_eq_length (by simpa using h)]
 
-theorem idxOf_lt_length [BEq α] [LawfulBEq α] {xs : Array α} (h : a ∈ xs) : xs.idxOf a < xs.size := by
+theorem idxOf_lt_length_of_mem [BEq α] [LawfulBEq α] {xs : Array α} (h : a ∈ xs) : xs.idxOf a < xs.size := by
   rcases xs with ⟨xs⟩
-  simp [List.idxOf_lt_length (by simpa using h)]
+  simp [List.idxOf_lt_length_of_mem (by simpa using h)]
 
+theorem idxOf_le_size [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
+    xs.idxOf a ≤ xs.size := by
+  rcases xs with ⟨xs⟩
+  simp [List.idxOf_le_length]
+
+grind_pattern idxOf_le_size => xs.idxOf a, xs.size
+
+theorem idxOf_lt_size_iff [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
+    xs.idxOf a < xs.size ↔ a ∈ xs := by
+  rcases xs with ⟨xs⟩
+  simp [List.idxOf_lt_length_iff]
+
+grind_pattern idxOf_lt_size_iff => xs.idxOf a, xs.size
 
 /-! ### idxOf?
 
@@ -702,19 +772,20 @@ The verification API for `idxOf?` is still incomplete.
 The lemmas below should be made consistent with those for `findIdx?` (and proved using them).
 -/
 
-theorem idxOf?_empty [BEq α] : (#[] : Array α).idxOf? a = none := by simp
+@[grind =] theorem idxOf?_empty [BEq α] : (#[] : Array α).idxOf? a = none := by simp
 
-@[simp] theorem idxOf?_eq_none_iff [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
+@[simp, grind =] theorem idxOf?_eq_none_iff [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
     xs.idxOf? a = none ↔ a ∉ xs := by
   rcases xs with ⟨xs⟩
   simp [List.idxOf?_eq_none_iff]
 
-@[simp]
+@[simp, grind =]
 theorem isSome_idxOf? [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
     (xs.idxOf? a).isSome ↔ a ∈ xs := by
   rcases xs with ⟨xs⟩
   simp
 
+@[grind =]
 theorem isNone_idxOf? [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
     (xs.idxOf? a).isNone = ¬ a ∈ xs := by
   simp
@@ -727,11 +798,11 @@ The lemmas below should be made consistent with those for `findFinIdx?` (and pro
 
 theorem idxOf?_eq_map_finIdxOf?_val [BEq α] {xs : Array α} {a : α} :
     xs.idxOf? a = (xs.finIdxOf? a).map (·.val) := by
-  simp [idxOf?, finIdxOf?, findIdx?_eq_map_findFinIdx?_val]
+  simp [idxOf?, finIdxOf?]
 
-theorem finIdxOf?_empty [BEq α] : (#[] : Array α).finIdxOf? a = none := by simp
+@[grind =] theorem finIdxOf?_empty [BEq α] : (#[] : Array α).finIdxOf? a = none := by simp
 
-@[simp] theorem finIdxOf?_eq_none_iff [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
+@[simp, grind =] theorem finIdxOf?_eq_none_iff [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
     xs.finIdxOf? a = none ↔ a ∉ xs := by
   rcases xs with ⟨xs⟩
   simp [List.finIdxOf?_eq_none_iff, Array.size]
@@ -742,14 +813,16 @@ theorem finIdxOf?_empty [BEq α] : (#[] : Array α).finIdxOf? a = none := by sim
   unfold Array.size at i ⊢
   simp [List.finIdxOf?_eq_some_iff]
 
-@[simp]
-theorem isSome_finIdxOf? [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
-    (xs.finIdxOf? a).isSome ↔ a ∈ xs := by
+@[simp, grind =]
+theorem isSome_finIdxOf? [BEq α] [PartialEquivBEq α] {xs : Array α} {a : α} :
+    (xs.finIdxOf? a).isSome = xs.contains a := by
   rcases xs with ⟨xs⟩
   simp [Array.size]
 
-theorem isNone_finIdxOf? [BEq α] [LawfulBEq α] {xs : Array α} {a : α} :
-    (xs.finIdxOf? a).isNone = ¬ a ∈ xs := by
-  simp
+@[simp, grind =]
+theorem isNone_finIdxOf? [BEq α] [PartialEquivBEq α] {xs : Array α} {a : α} :
+    (xs.finIdxOf? a).isNone = !xs.contains a := by
+  rcases xs with ⟨xs⟩
+  simp [Array.size]
 
 end Array

src/Init/Data/Array/InsertIdx.lean

@@ -47,11 +47,16 @@ theorem insertIdx_zero {xs : Array α} {x : α} : xs.insertIdx 0 x = #[x] ++ xs
   simp at h
   simp [List.length_insertIdx, h]
 
-theorem eraseIdx_insertIdx {i : Nat} {xs : Array α} (h : i ≤ xs.size) :
+theorem eraseIdx_insertIdx_self {i : Nat} {xs : Array α} (h : i ≤ xs.size) :
     (xs.insertIdx i a).eraseIdx i (by simp; omega) = xs := by
   rcases xs with ⟨xs⟩
   simp_all
 
+@[deprecated eraseIdx_insertIdx_self (since := "2025-06-15")]
+theorem eraseIdx_insertIdx {i : Nat} {xs : Array α} (h : i ≤ xs.size) :
+    (xs.insertIdx i a).eraseIdx i (by simp; omega) = xs := by
+  simp [eraseIdx_insertIdx_self]
+
 theorem insertIdx_eraseIdx_of_ge {as : Array α}
     (w₁ : i < as.size) (w₂ : j ≤ (as.eraseIdx i).size) (h : i ≤ j) :
     (as.eraseIdx i).insertIdx j a =
@@ -66,6 +71,18 @@ theorem insertIdx_eraseIdx_of_le {as : Array α}
   cases as
   simpa using List.insertIdx_eraseIdx_of_le (by simpa) (by simpa)
 
+@[grind =]
+theorem insertIdx_eraseIdx {as : Array α} (h₁ : i < as.size) (h₂ : j ≤ (as.eraseIdx i).size) :
+    (as.eraseIdx i).insertIdx j a =
+      if h : i ≤ j then
+        (as.insertIdx (j + 1) a (by simp_all; omega)).eraseIdx i (by simp_all; omega)
+      else
+        (as.insertIdx j a).eraseIdx (i + 1) (by simp_all) := by
+  split <;> rename_i h'
+  · rw [insertIdx_eraseIdx_of_ge] <;> omega
+  · rw [insertIdx_eraseIdx_of_le] <;> omega
+
+@[grind =]
 theorem insertIdx_comm (a b : α) {i j : Nat} {xs : Array α} (_ : i ≤ j) (_ : j ≤ xs.size) :
     (xs.insertIdx i a).insertIdx (j + 1) b (by simpa) =
       (xs.insertIdx j b).insertIdx i a (by simp; omega) := by
@@ -81,6 +98,7 @@ theorem insertIdx_size_self {xs : Array α} {x : α} : xs.insertIdx xs.size x =
   rcases xs with ⟨xs⟩
   simp
 
+@[grind =]
 theorem getElem_insertIdx {xs : Array α} {x : α} {i k : Nat} (w : i ≤ xs.size) (h : k < (xs.insertIdx i x).size) :
     (xs.insertIdx i x)[k] =
       if h₁ : k < i then
@@ -91,21 +109,22 @@ theorem getElem_insertIdx {xs : Array α} {x : α} {i k : Nat} (w : i ≤ xs.siz
         else
           xs[k-1]'(by simp [size_insertIdx] at h; omega) := by
   cases xs
-  simp [List.getElem_insertIdx, w]
+  simp [List.getElem_insertIdx]
 
 theorem getElem_insertIdx_of_lt {xs : Array α} {x : α} {i k : Nat} (w : i ≤ xs.size) (h : k < i) :
     (xs.insertIdx i x)[k]'(by simp; omega) = xs[k] := by
-  simp [getElem_insertIdx, w, h]
+  simp [getElem_insertIdx, h]
 
 theorem getElem_insertIdx_self {xs : Array α} {x : α} {i : Nat} (w : i ≤ xs.size) :
     (xs.insertIdx i x)[i]'(by simp; omega) = x := by
-  simp [getElem_insertIdx, w]
+  simp [getElem_insertIdx]
 
 theorem getElem_insertIdx_of_gt {xs : Array α} {x : α} {i k : Nat} (w : k ≤ xs.size) (h : k > i) :
     (xs.insertIdx i x)[k]'(by simp; omega) = xs[k - 1]'(by omega) := by
-  simp [getElem_insertIdx, w, h]
+  simp [getElem_insertIdx]
   rw [dif_neg (by omega), dif_neg (by omega)]
 
+@[grind =]
 theorem getElem?_insertIdx {xs : Array α} {x : α} {i k : Nat} (h : i ≤ xs.size) :
     (xs.insertIdx i x)[k]? =
       if k < i then
@@ -116,7 +135,7 @@ theorem getElem?_insertIdx {xs : Array α} {x : α} {i k : Nat} (h : i ≤ xs.si
         else
           xs[k-1]? := by
   cases xs
-  simp [List.getElem?_insertIdx, h]
+  simp [List.getElem?_insertIdx]
 
 theorem getElem?_insertIdx_of_lt {xs : Array α} {x : α} {i k : Nat} (w : i ≤ xs.size) (h : k < i) :
     (xs.insertIdx i x)[k]? = xs[k]? := by

src/Init/Data/Array/Lemmas.lean

@@ -89,6 +89,8 @@ theorem size_pos_of_mem {a : α} {xs : Array α} (h : a ∈ xs) : 0 < xs.size :=
   simp only [mem_toArray] at h
   simpa using List.length_pos_of_mem h
 
+grind_pattern size_pos_of_mem => a ∈ xs, xs.size
+
 theorem exists_mem_of_size_pos {xs : Array α} (h : 0 < xs.size) : ∃ a, a ∈ xs := by
   cases xs
   simpa using List.exists_mem_of_length_pos h
@@ -123,7 +125,7 @@ theorem none_eq_getElem?_iff {xs : Array α} {i : Nat} : none = xs[i]? ↔ xs.si
   simp
 
 theorem getElem?_eq_none {xs : Array α} (h : xs.size ≤ i) : xs[i]? = none := by
-  simp [getElem?_eq_none_iff, h]
+  simp [h]
 
 grind_pattern Array.getElem?_eq_none => xs.size ≤ i, xs[i]?
 
@@ -133,7 +135,6 @@ grind_pattern Array.getElem?_eq_none => xs.size ≤ i, xs[i]?
 theorem getElem?_eq_some_iff {xs : Array α} : xs[i]? = some b ↔ ∃ h : i < xs.size, xs[i] = b :=
   _root_.getElem?_eq_some_iff
 
-@[grind →]
 theorem getElem_of_getElem? {xs : Array α} : xs[i]? = some a → ∃ h : i < xs.size, xs[i] = a :=
   getElem?_eq_some_iff.mp
 
@@ -153,16 +154,16 @@ theorem getElem_eq_iff {xs : Array α} {i : Nat} {h : i < xs.size} : xs[i] = x
   exact ⟨fun w => ⟨h, w⟩, fun h => h.2⟩
 
 theorem getElem_eq_getElem?_get {xs : Array α} {i : Nat} (h : i < xs.size) :
-    xs[i] = xs[i]?.get (by simp [getElem?_eq_getElem, h]) := by
-  simp [getElem_eq_iff]
+    xs[i] = xs[i]?.get (by simp [h]) := by
+  simp
 
 theorem getD_getElem? {xs : Array α} {i : Nat} {d : α} :
     xs[i]?.getD d = if p : i < xs.size then xs[i]'p else d := by
   if h : i < xs.size then
-    simp [h, getElem?_def]
+    simp [h]
   else
     have p : i ≥ xs.size := Nat.le_of_not_gt h
-    simp [getElem?_eq_none p, h]
+    simp [h]
 
 @[simp] theorem getElem?_empty {i : Nat} : (#[] : Array α)[i]? = none := rfl
 
@@ -174,14 +175,14 @@ theorem getElem_push_lt {xs : Array α} {x : α} {i : Nat} (h : i < xs.size) :
 
 @[simp] theorem getElem_push_eq {xs : Array α} {x : α} : (xs.push x)[xs.size] = x := by
   simp only [push, ← getElem_toList, List.concat_eq_append]
-  rw [List.getElem_append_right] <;> simp [← getElem_toList, Nat.zero_lt_one]
+  rw [List.getElem_append_right] <;> simp
 
-theorem getElem_push {xs : Array α} {x : α} {i : Nat} (h : i < (xs.push x).size) :
+@[grind =] theorem getElem_push {xs : Array α} {x : α} {i : Nat} (h : i < (xs.push x).size) :
     (xs.push x)[i] = if h : i < xs.size then xs[i] else x := by
   by_cases h' : i < xs.size
   · simp [getElem_push_lt, h']
   · simp at h
-    simp [getElem_push_lt, Nat.le_antisymm (Nat.le_of_lt_succ h) (Nat.ge_of_not_lt h')]
+    simp [Nat.le_antisymm (Nat.le_of_lt_succ h) (Nat.ge_of_not_lt h')]
 
 @[grind =] theorem getElem?_push {xs : Array α} {x} : (xs.push x)[i]? = if i = xs.size then some x else xs[i]? := by
   simp [getElem?_def, getElem_push]
@@ -763,6 +764,7 @@ theorem all_eq_false' {p : α → Bool} {as : Array α} :
   rw [Bool.eq_false_iff, Ne, all_eq_true']
   simp
 
+@[grind =]
 theorem any_eq {xs : Array α} {p : α → Bool} : xs.any p = decide (∃ i : Nat, ∃ h, p (xs[i]'h)) := by
   by_cases h : xs.any p
   · simp_all [any_eq_true]
@@ -777,6 +779,7 @@ theorem any_eq' {xs : Array α} {p : α → Bool} : xs.any p = decide (∃ x, x
     simp only [any_eq_false'] at h
     simpa using h
 
+@[grind =]
 theorem all_eq {xs : Array α} {p : α → Bool} : xs.all p = decide (∀ i, (_ : i < xs.size) → p xs[i]) := by
   by_cases h : xs.all p
   · simp_all [all_eq_true]
@@ -903,7 +906,7 @@ theorem all_push [BEq α] {xs : Array α} {a : α} {p : α → Bool} :
 abbrev getElem_set_eq := @getElem_set_self
 
 @[simp] theorem getElem?_set_self {xs : Array α} {i : Nat} (h : i < xs.size) {v : α} :
-    (xs.set i v)[i]? = some v := by simp [getElem?_eq_getElem, h]
+    (xs.set i v)[i]? = some v := by simp [h]
 
 @[deprecated getElem?_set_self (since := "2024-12-11")]
 abbrev getElem?_set_eq := @getElem?_set_self
@@ -915,7 +918,7 @@ abbrev getElem?_set_eq := @getElem?_set_self
 
 @[simp] theorem getElem?_set_ne {xs : Array α} {i : Nat} (h : i < xs.size) {v : α} {j : Nat}
     (ne : i ≠ j) : (xs.set i v)[j]? = xs[j]? := by
-  by_cases h : j < xs.size <;> simp [getElem?_eq_getElem, getElem?_eq_none, Nat.ge_of_not_lt, ne, h]
+  by_cases h : j < xs.size <;> simp [ne, h]
 
 @[grind] theorem getElem_set {xs : Array α} {i : Nat} (h' : i < xs.size) {v : α} {j : Nat}
     (h : j < (xs.set i v).size) :
@@ -952,6 +955,13 @@ theorem set_push {xs : Array α} {x y : α} {h} :
         · simp at h
           omega
 
+@[grind _=_]
+theorem set_pop {xs : Array α} {x : α} {i : Nat} (h : i < xs.pop.size) :
+    xs.pop.set i x h = (xs.set i x (by simp at h; omega)).pop := by
+  ext i h₁ h₂
+  · simp
+  · simp [getElem_set]
+
 @[simp] theorem set_eq_empty_iff {xs : Array α} {i : Nat} {a : α} {h : i < xs.size} :
     xs.set i a = #[] ↔ xs = #[] := by
   cases xs <;> cases i <;> simp [set]
@@ -984,7 +994,11 @@ theorem mem_or_eq_of_mem_set
 @[simp, grind] theorem setIfInBounds_empty {i : Nat} {a : α} :
     #[].setIfInBounds i a = #[] := rfl
 
-@[simp] theorem set!_eq_setIfInBounds : @set! = @setIfInBounds := rfl
+@[simp, grind =] theorem set!_eq_setIfInBounds : set! xs i v = setIfInBounds xs i v := rfl
+
+@[grind]
+theorem setIfInBounds_def (xs : Array α) (i : Nat) (a : α) :
+    xs.setIfInBounds i a = if h : i < xs.size then xs.set i a else xs := rfl
 
 @[deprecated set!_eq_setIfInBounds (since := "2024-12-12")]
 abbrev set!_is_setIfInBounds := @set!_eq_setIfInBounds
@@ -1030,7 +1044,7 @@ theorem getElem?_setIfInBounds_self {xs : Array α} {i : Nat} {a : α} :
 @[simp]
 theorem getElem?_setIfInBounds_self_of_lt {xs : Array α} {i : Nat} {a : α} (h : i < xs.size) :
     (xs.setIfInBounds i a)[i]? = some a := by
-  simp [getElem?_setIfInBounds, h]
+  simp [h]
 
 @[deprecated getElem?_setIfInBounds_self (since := "2024-12-11")]
 abbrev getElem?_setIfInBounds_eq := @getElem?_setIfInBounds_self
@@ -1074,9 +1088,9 @@ theorem mem_or_eq_of_mem_setIfInBounds
 @[simp] theorem getD_getElem?_setIfInBounds {xs : Array α} {i : Nat} {v d : α} :
     (xs.setIfInBounds i v)[i]?.getD d = if i < xs.size then v else d := by
   by_cases h : i < xs.size <;>
-    simp [setIfInBounds, Nat.not_lt_of_le, h,  getD_getElem?]
+    simp [setIfInBounds, h,  ]
 
-@[simp] theorem toList_setIfInBounds {xs : Array α} {i : Nat} {x : α} :
+@[simp, grind =] theorem toList_setIfInBounds {xs : Array α} {i : Nat} {x : α} :
     (xs.setIfInBounds i x).toList = xs.toList.set i x := by
   simp only [setIfInBounds]
   split <;> rename_i h
@@ -1186,7 +1200,7 @@ where
       mapM.map f xs i bs = (xs.toList.drop i).foldlM (fun bs a => bs.push <$> f a) bs := by
     unfold mapM.map; split
     · rw [← List.getElem_cons_drop_succ_eq_drop ‹_›]
-      simp only [aux (i + 1), map_eq_pure_bind, length_toList, List.foldlM_cons, bind_assoc,
+      simp only [aux (i + 1), map_eq_pure_bind, List.foldlM_cons, bind_assoc,
         pure_bind]
       rfl
     · rw [List.drop_of_length_le (Nat.ge_of_not_lt ‹_›)]; rfl
@@ -1258,7 +1272,8 @@ theorem map_singleton {f : α → β} {a : α} : map f #[a] = #[f a] := by simp
 
 -- We use a lower priority here as there are more specific lemmas in downstream libraries
 -- which should be able to fire first.
-@[simp 500] theorem mem_map {f : α → β} {xs : Array α} : b ∈ xs.map f ↔ ∃ a, a ∈ xs ∧ f a = b := by
+@[simp 500, grind =] theorem mem_map {f : α → β} {xs : Array α} :
+    b ∈ xs.map f ↔ ∃ a, a ∈ xs ∧ f a = b := by
   simp only [mem_def, toList_map, List.mem_map]
 
 theorem exists_of_mem_map (h : b ∈ map f l) : ∃ a, a ∈ l ∧ f a = b := mem_map.1 h
@@ -1485,6 +1500,19 @@ theorem forall_mem_filter {p : α → Bool} {xs : Array α} {P : α → Prop} :
     (∀ (i) (_ : i ∈ xs.filter p), P i) ↔ ∀ (j) (_ : j ∈ xs), p j → P j := by
   simp
 
+@[grind] theorem getElem_filter {xs : Array α} {p : α → Bool} {i : Nat} (h : i < (xs.filter p).size) :
+    p (xs.filter p)[i] :=
+  (mem_filter.mp (getElem_mem h)).2
+
+theorem getElem?_filter {xs : Array α} {p : α → Bool} {i : Nat} (h : i < (xs.filter p).size)
+    (w : (xs.filter p)[i]? = some a) : p a := by
+  rw [getElem?_eq_getElem] at w
+  simp only [Option.some.injEq] at w
+  rw [← w]
+  apply getElem_filter h
+
+grind_pattern getElem?_filter => (xs.filter p)[i]?, some a
+
 @[simp] theorem filter_filter {p q : α → Bool} {xs : Array α} :
     filter p (filter q xs) = filter (fun a => p a && q a) xs := by
   apply ext'
@@ -1727,7 +1755,7 @@ theorem forall_mem_filterMap {f : α → Option β} {xs : Array α} {P : β →
 
 theorem map_filterMap_of_inv {f : α → Option β} {g : β → α} (H : ∀ x : α, (f x).map g = some x) {xs : Array α} :
     map g (filterMap f xs) = xs := by
-  simp only [map_filterMap, H, filterMap_some, id]
+  simp only [map_filterMap, H, filterMap_some]
 
 @[grind →]
 theorem forall_none_of_filterMap_eq_empty (h : filterMap f xs = #[]) : ∀ x ∈ xs, f x = none := by
@@ -1866,7 +1894,7 @@ theorem getElem?_append_left {xs ys : Array α} {i : Nat} (hn : i < xs.size) :
     (xs ++ ys)[i]? = xs[i]? := by
   have hn' : i < (xs ++ ys).size := Nat.lt_of_lt_of_le hn <|
     size_append .. ▸ Nat.le_add_right ..
-  simp_all [getElem?_eq_getElem, getElem_append]
+  simp_all
 
 theorem getElem?_append_right {xs ys : Array α} {i : Nat} (h : xs.size ≤ i) :
     (xs ++ ys)[i]? = ys[i - xs.size]? := by
@@ -1997,7 +2025,7 @@ theorem append_eq_singleton_iff {xs ys : Array α} {x : α} :
     xs ++ ys = #[x] ↔ (xs = #[] ∧ ys = #[x]) ∨ (xs = #[x] ∧ ys = #[]) := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
-  simp only [List.append_toArray, mk.injEq, List.append_eq_singleton_iff, toArray_eq_append_iff]
+  simp only [List.append_toArray, mk.injEq, List.append_eq_singleton_iff]
 
 theorem singleton_eq_append_iff {xs ys : Array α} {x : α} :
     #[x] = xs ++ ys ↔ (xs = #[] ∧ ys = #[x]) ∨ (xs = #[x] ∧ ys = #[]) := by
@@ -2323,7 +2351,7 @@ theorem flatMap_toArray {β} {f : α → Array β} {as : List α} :
 theorem size_flatMap {xs : Array α} {f : α → Array β} :
     (xs.flatMap f).size = sum (map (fun a => (f a).size) xs) := by
   rcases xs with ⟨l⟩
-  simp [Function.comp_def]
+  simp
 
 @[simp, grind] theorem mem_flatMap {f : α → Array β} {b} {xs : Array α} : b ∈ xs.flatMap f ↔ ∃ a, a ∈ xs ∧ b ∈ f a := by
   simp [flatMap_def, mem_flatten]
@@ -2541,7 +2569,7 @@ abbrev map_mkArray := @map_replicate
 @[grind] theorem filter_replicate (w : stop = n) :
     (replicate n a).filter p 0 stop = if p a then replicate n a else #[] := by
   apply Array.ext'
-  simp only [w, toList_filter', toList_replicate, List.filter_replicate]
+  simp only [w]
   split <;> simp_all
 
 @[deprecated filter_replicate (since := "2025-03-18")]
@@ -2581,7 +2609,7 @@ abbrev filterMap_mkArray_of_some := @filterMap_replicate_of_some
 @[simp] theorem filterMap_replicate_of_isSome {f : α → Option β} (h : (f a).isSome) :
     (replicate n a).filterMap f = replicate n (Option.get _ h) := by
   match w : f a, h with
-  | some b, _ => simp [filterMap_replicate, h, w]
+  | some b, _ => simp [filterMap_replicate, w]
 
 @[deprecated filterMap_replicate_of_isSome (since := "2025-03-18")]
 abbrev filterMap_mkArray_of_isSome := @filterMap_replicate_of_isSome
@@ -2616,7 +2644,7 @@ abbrev flatten_mkArray_replicate := @flatten_replicate_replicate
 
 theorem flatMap_replicate {f : α → Array β} : (replicate n a).flatMap f = (replicate n (f a)).flatten := by
   rw [← toList_inj]
-  simp [flatMap_toList, List.flatMap_replicate]
+  simp [List.flatMap_replicate]
 
 @[deprecated flatMap_replicate (since := "2025-03-18")]
 abbrev flatMap_mkArray := @flatMap_replicate
@@ -2994,6 +3022,10 @@ theorem extract_empty_of_size_le_start {xs : Array α} {start stop : Nat} (h : x
   apply ext'
   simp
 
+theorem _root_.List.toArray_drop {l : List α} {k : Nat} :
+    (l.drop k).toArray = l.toArray.extract k := by
+  rw [List.drop_eq_extract, List.extract_toArray, List.size_toArray]
+
 @[deprecated extract_size (since := "2025-02-27")]
 theorem take_size {xs : Array α} : xs.take xs.size = xs := by
   cases xs
@@ -3604,8 +3636,8 @@ We can prove that two folds over the same array are related (by some arbitrary r
 if we know that the initial elements are related and the folding function, for each element of the array,
 preserves the relation.
 -/
-theorem foldl_rel {xs : Array α} {f g : β → α → β} {a b : β} {r : β → β → Prop}
-    (h : r a b) (h' : ∀ (a : α), a ∈ xs → ∀ (c c' : β), r c c' → r (f c a) (g c' a)) :
+theorem foldl_rel {xs : Array α} {f : β → α → β} {g : γ → α → γ} {a : β} {b : γ} {r : β → γ → Prop}
+    (h : r a b) (h' : ∀ (a : α), a ∈ xs → ∀ (c : β) (c' : γ), r c c' → r (f c a) (g c' a)) :
     r (xs.foldl (fun acc a => f acc a) a) (xs.foldl (fun acc a => g acc a) b) := by
   rcases xs with ⟨xs⟩
   simpa using List.foldl_rel h (by simpa using h')
@@ -3615,8 +3647,8 @@ We can prove that two folds over the same array are related (by some arbitrary r
 if we know that the initial elements are related and the folding function, for each element of the array,
 preserves the relation.
 -/
-theorem foldr_rel {xs : Array α} {f g : α → β → β} {a b : β} {r : β → β → Prop}
-    (h : r a b) (h' : ∀ (a : α), a ∈ xs → ∀ (c c' : β), r c c' → r (f a c) (g a c')) :
+theorem foldr_rel {xs : Array α} {f : α → β → β} {g : α → γ → γ} {a : β} {b : γ} {r : β → γ → Prop}
+    (h : r a b) (h' : ∀ (a : α), a ∈ xs → ∀ (c : β) (c' : γ), r c c' → r (f a c) (g a c')) :
     r (xs.foldr (fun a acc => f a acc) a) (xs.foldr (fun a acc => g a acc) b) := by
   rcases xs with ⟨xs⟩
   simpa using List.foldr_rel h (by simpa using h')
@@ -3731,7 +3763,7 @@ theorem back?_replicate {a : α} {n : Nat} :
 @[deprecated back?_replicate (since := "2025-03-18")]
 abbrev back?_mkArray := @back?_replicate
 
-@[simp] theorem back_replicate (w : 0 < n) : (replicate n a).back (by simpa using w) = a := by
+@[simp] theorem back_replicate {xs : Array α} (w : 0 < n) : (replicate n xs).back (by simpa using w) = xs := by
   simp [back_eq_getElem]
 
 @[deprecated back_replicate (since := "2025-03-18")]
@@ -4074,11 +4106,11 @@ abbrev all_mkArray := @all_replicate
 
 /-! ### modify -/
 
-@[simp] theorem size_modify {xs : Array α} {i : Nat} {f : α → α} : (xs.modify i f).size = xs.size := by
+@[simp, grind =] theorem size_modify {xs : Array α} {i : Nat} {f : α → α} : (xs.modify i f).size = xs.size := by
   unfold modify modifyM
   split <;> simp
 
-theorem getElem_modify {xs : Array α} {j i} (h : i < (xs.modify j f).size) :
+@[grind =] theorem getElem_modify {xs : Array α} {j i} (h : i < (xs.modify j f).size) :
     (xs.modify j f)[i] = if j = i then f (xs[i]'(by simpa using h)) else xs[i]'(by simpa using h) := by
   simp only [modify, modifyM]
   split
@@ -4086,7 +4118,7 @@ theorem getElem_modify {xs : Array α} {j i} (h : i < (xs.modify j f).size) :
   · simp only [Id.run_pure]
     rw [if_neg (mt (by rintro rfl; exact h) (by simp_all))]
 
-@[simp] theorem toList_modify {xs : Array α} {f : α → α} {i : Nat} :
+@[simp, grind =] theorem toList_modify {xs : Array α} {f : α → α} {i : Nat} :
     (xs.modify i f).toList = xs.toList.modify i f := by
   apply List.ext_getElem
   · simp
@@ -4101,7 +4133,7 @@ theorem getElem_modify_of_ne {xs : Array α} {i : Nat} (h : i ≠ j)
     (xs.modify i f)[j] = xs[j]'(by simpa using hj) := by
   simp [getElem_modify hj, h]
 
-theorem getElem?_modify {xs : Array α} {i : Nat} {f : α → α} {j : Nat} :
+@[grind =] theorem getElem?_modify {xs : Array α} {i : Nat} {f : α → α} {j : Nat} :
     (xs.modify i f)[j]? = if i = j then xs[j]?.map f else xs[j]? := by
   simp only [getElem?_def, size_modify, getElem_modify, Option.map_dif]
   split <;> split <;> rfl
@@ -4110,7 +4142,7 @@ theorem getElem?_modify {xs : Array α} {i : Nat} {f : α → α} {j : Nat} :
 
 @[simp] theorem getElem_swap_right {xs : Array α} {i j : Nat} {hi hj} :
     (xs.swap i j hi hj)[j]'(by simpa using hj) = xs[i] := by
-  simp [swap_def, getElem_set]
+  simp [swap_def]
 
 @[simp] theorem getElem_swap_left {xs : Array α} {i j : Nat} {hi hj} :
     (xs.swap i j hi hj)[i]'(by simpa using hi) = xs[j] := by
@@ -4150,18 +4182,18 @@ theorem swap_comm {xs : Array α} {i j : Nat} (hi hj) : xs.swap i j hi hj = xs.s
     · split <;> simp_all
     · split <;> simp_all
 
-@[simp] theorem size_swapIfInBounds {xs : Array α} {i j : Nat} :
+@[simp, grind =] theorem size_swapIfInBounds {xs : Array α} {i j : Nat} :
     (xs.swapIfInBounds i j).size = xs.size := by unfold swapIfInBounds; split <;> (try split) <;> simp [size_swap]
 
 /-! ### swapAt -/
 
-@[simp] theorem swapAt_def {xs : Array α} {i : Nat} {v : α} (hi) :
+@[simp, grind =] theorem swapAt_def {xs : Array α} {i : Nat} {v : α} (hi) :
     xs.swapAt i v hi = (xs[i], xs.set i v) := rfl
 
 theorem size_swapAt {xs : Array α} {i : Nat} {v : α} (hi) :
     (xs.swapAt i v hi).2.size = xs.size := by simp
 
-@[simp]
+@[simp, grind =]
 theorem swapAt!_def {xs : Array α} {i : Nat} {v : α} (h : i < xs.size) :
     xs.swapAt! i v = (xs[i], xs.set i v) := by simp [swapAt!, h]
 
@@ -4329,42 +4361,44 @@ theorem getElem?_ofFn {f : Fin n → α} {i : Nat} :
 
 /-! ### Preliminaries about `range` and `range'` -/
 
-@[simp] theorem size_range' {start size step} : (range' start size step).size = size := by
+@[simp, grind =] theorem size_range' {start size step} : (range' start size step).size = size := by
   simp [range']
 
-@[simp] theorem toList_range' {start size step} :
+@[simp, grind =] theorem toList_range' {start size step} :
      (range' start size step).toList = List.range' start size step := by
   apply List.ext_getElem <;> simp [range']
 
-@[simp]
+@[simp, grind =]
 theorem getElem_range' {start size step : Nat} {i : Nat}
     (h : i < (Array.range' start size step).size) :
     (Array.range' start size step)[i] = start + step * i := by
   simp [← getElem_toList]
 
+@[grind =]
 theorem getElem?_range' {start size step : Nat} {i : Nat} :
     (Array.range' start size step)[i]? = if i < size then some (start + step * i) else none := by
   simp [getElem?_def, getElem_range']
 
-@[simp] theorem _root_.List.toArray_range' {start size step : Nat} :
+@[simp, grind =] theorem _root_.List.toArray_range' {start size step : Nat} :
     (List.range' start size step).toArray = Array.range' start size step := by
   apply ext'
   simp
 
-@[simp] theorem size_range {n : Nat} : (range n).size = n := by
+@[simp, grind =] theorem size_range {n : Nat} : (range n).size = n := by
   simp [range]
 
-@[simp] theorem toList_range {n : Nat} : (range n).toList = List.range n := by
+@[simp, grind =] theorem toList_range {n : Nat} : (range n).toList = List.range n := by
   apply List.ext_getElem <;> simp [range]
 
-@[simp]
+@[simp, grind =]
 theorem getElem_range {n : Nat} {i : Nat} (h : i < (Array.range n).size) : (Array.range n)[i] = i := by
   simp [← getElem_toList]
 
+@[grind =]
 theorem getElem?_range {n : Nat} {i : Nat} : (Array.range n)[i]? = if i < n then some i else none := by
   simp [getElem?_def, getElem_range]
 
-@[simp] theorem _root_.List.toArray_range {n : Nat} : (List.range n).toArray = Array.range n := by
+@[simp, grind =] theorem _root_.List.toArray_range {n : Nat} : (List.range n).toArray = Array.range n := by
   apply ext'
   simp
 
@@ -4405,7 +4439,7 @@ theorem size_uset {xs : Array α} {v : α} {i : USize} (h : i.toNat < xs.size) :
 
 @[simp] theorem getD_eq_getD_getElem? {xs : Array α} {i : Nat} {d : α} :
     xs.getD i d = xs[i]?.getD d := by
-  simp only [getD]; split <;> simp [getD_getElem?, *]
+  simp only [getD]; split <;> simp [*]
 
 theorem getElem!_eq_getD [Inhabited α] {xs : Array α} {i} : xs[i]! = xs.getD i default := by
   rfl
@@ -4433,13 +4467,13 @@ theorem getElem?_size_le {xs : Array α} {i : Nat} (h : xs.size ≤ i) : xs[i]?
   simp [getElem?_neg, h]
 
 theorem getElem_mem_toList {xs : Array α} {i : Nat} (h : i < xs.size) : xs[i] ∈ xs.toList := by
-  simp only [← getElem_toList, List.getElem_mem, ugetElem_eq_getElem]
+  simp only [← getElem_toList, List.getElem_mem]
 
 theorem back!_eq_back? [Inhabited α] {xs : Array α} : xs.back! = xs.back?.getD default := by
   simp [back!, back?, getElem!_def, Option.getD]; rfl
 
 @[simp, grind] theorem back?_push {xs : Array α} {x : α} : (xs.push x).back? = some x := by
-  simp [back?, ← getElem?_toList]
+  simp [back?]
 
 @[simp] theorem back!_push [Inhabited α] {xs : Array α} {x : α} : (xs.push x).back! = x := by
   simp [back!_eq_back?]
@@ -4507,7 +4541,7 @@ abbrev contains_def [DecidableEq α] {a : α} {xs : Array α} : xs.contains a
     (zip xs ys).size = min xs.size ys.size :=
   size_zipWith
 
-@[simp] theorem getElem_zipWith {xs : Array α} {ys : Array β} {f : α → β → γ} {i : Nat}
+@[simp, grind =] theorem getElem_zipWith {xs : Array α} {ys : Array β} {f : α → β → γ} {i : Nat}
     (hi : i < (zipWith f xs ys).size) :
     (zipWith f xs ys)[i] = f (xs[i]'(by simp at hi; omega)) (ys[i]'(by simp at hi; omega)) := by
   cases xs
@@ -4588,7 +4622,7 @@ theorem uset_toArray {l : List α} {i : USize} {a : α} {h : i.toNat < l.toArray
 @[simp, grind =] theorem flatten_toArray {L : List (List α)} :
     (L.toArray.map List.toArray).flatten = L.flatten.toArray := by
   apply ext'
-  simp [Function.comp_def]
+  simp
 
 end List
 
@@ -4680,7 +4714,7 @@ namespace List
       intro h'
       specialize ih (by omega)
       have : as.length - (i + 1) + 1 = as.length - i := by omega
-      simp_all [ih]
+      simp_all
     · simp only [size_toArray, Nat.not_lt] at h
       have : as.length = 0 := by omega
       simp_all
@@ -4691,7 +4725,7 @@ end List
 namespace Array
 
 @[deprecated size_toArray (since := "2024-12-11")]
-theorem size_mk (as : List α) : (Array.mk as).size = as.length := by simp [size]
+theorem size_mk (as : List α) : (Array.mk as).size = as.length := by simp
 
 @[deprecated getElem?_eq_getElem (since := "2024-12-11")]
 theorem getElem?_lt
@@ -4707,7 +4741,7 @@ theorem get?_eq_getElem? (xs : Array α) (i : Nat) : xs.get? i = xs[i]? := rfl
 
 @[deprecated getElem?_eq_none (since := "2024-12-11")]
 theorem getElem?_len_le (xs : Array α) {i : Nat} (h : xs.size ≤ i) : xs[i]? = none := by
-  simp [getElem?_eq_none, h]
+  simp [h]
 
 @[deprecated getD_getElem? (since := "2024-12-11")] abbrev getD_get? := @getD_getElem?
 
@@ -4722,7 +4756,7 @@ set_option linter.deprecated false in
 theorem get!_eq_getD_getElem? [Inhabited α] (xs : Array α) (i : Nat) :
     xs.get! i = xs[i]?.getD default := by
   by_cases p : i < xs.size <;>
-  simp [get!, getElem!_eq_getD, getD_eq_getD_getElem?, getD_getElem?, p]
+  simp [get!, getD_eq_getD_getElem?, p]
 
 set_option linter.deprecated false in
 @[deprecated get!_eq_getD_getElem? (since := "2025-02-12")] abbrev get!_eq_getElem? := @get!_eq_getD_getElem?

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

@@ -162,7 +162,7 @@ instance [DecidableEq α] [LT α] [DecidableLT α]
     {xs ys : Array α} : lex xs ys = false ↔ ys ≤ xs := by
   cases xs
   cases ys
-  simp [List.not_lt_iff_ge]
+  simp
 
 instance [DecidableEq α] [LT α] [DecidableLT α] : DecidableLT (Array α) :=
   fun xs ys => decidable_of_iff (lex xs ys = true) lex_eq_true_iff_lt

src/Init/Data/Array/MapIdx.lean

@@ -51,27 +51,27 @@ theorem mapFinIdx_spec {xs : Array α} {f : (i : Nat) → α → (h : i < xs.siz
       ∀ i h, p i ((Array.mapFinIdx xs f)[i]) h :=
   (mapFinIdx_induction _ _ (fun _ => True) trivial p fun _ _ _ => ⟨hs .., trivial⟩).2
 
-@[simp] theorem size_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
+@[simp, grind =] theorem size_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
     (xs.mapFinIdx f).size = xs.size :=
   (mapFinIdx_spec (p := fun _ _ _ => True) (hs := fun _ _ => trivial)).1
 
-@[simp] theorem size_zipIdx {xs : Array α} {k : Nat} : (xs.zipIdx k).size = xs.size :=
+@[simp, grind =] theorem size_zipIdx {xs : Array α} {k : Nat} : (xs.zipIdx k).size = xs.size :=
   Array.size_mapFinIdx
 
 @[deprecated size_zipIdx (since := "2025-01-21")] abbrev size_zipWithIndex := @size_zipIdx
 
-@[simp] theorem getElem_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} {i : Nat}
+@[simp, grind =] theorem getElem_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} {i : Nat}
     (h : i < (xs.mapFinIdx f).size) :
     (xs.mapFinIdx f)[i] = f i (xs[i]'(by simp_all)) (by simp_all) :=
   (mapFinIdx_spec (p := fun i b h => b = f i xs[i] h) fun _ _ => rfl).2 i _
 
-@[simp] theorem getElem?_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} {i : Nat} :
+@[simp, grind =] theorem getElem?_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} {i : Nat} :
     (xs.mapFinIdx f)[i]? =
       xs[i]?.pbind fun b h => some <| f i b (getElem?_eq_some_iff.1 h).1 := by
   simp only [getElem?_def, size_mapFinIdx, getElem_mapFinIdx]
   split <;> simp_all
 
-@[simp] theorem toList_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
+@[simp, grind =] theorem toList_mapFinIdx {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
     (xs.mapFinIdx f).toList = xs.toList.mapFinIdx (fun i a h => f i a (by simpa)) := by
   apply List.ext_getElem <;> simp
 
@@ -91,20 +91,20 @@ theorem mapIdx_spec {f : Nat → α → β} {xs : Array α}
       ∀ i h, p i ((xs.mapIdx f)[i]) h :=
   (mapIdx_induction (motive := fun _ => True) trivial fun _ _ _ => ⟨hs .., trivial⟩).2
 
-@[simp] theorem size_mapIdx {f : Nat → α → β} {xs : Array α} : (xs.mapIdx f).size = xs.size :=
+@[simp, grind =] theorem size_mapIdx {f : Nat → α → β} {xs : Array α} : (xs.mapIdx f).size = xs.size :=
   (mapIdx_spec (p := fun _ _ _ => True) (hs := fun _ _ => trivial)).1
 
-@[simp] theorem getElem_mapIdx {f : Nat → α → β} {xs : Array α} {i : Nat}
+@[simp, grind =] theorem getElem_mapIdx {f : Nat → α → β} {xs : Array α} {i : Nat}
     (h : i < (xs.mapIdx f).size) :
     (xs.mapIdx f)[i] = f i (xs[i]'(by simp_all)) :=
   (mapIdx_spec (p := fun i b h => b = f i xs[i]) fun _ _ => rfl).2 i (by simp_all)
 
-@[simp] theorem getElem?_mapIdx {f : Nat → α → β} {xs : Array α} {i : Nat} :
+@[simp, grind =] theorem getElem?_mapIdx {f : Nat → α → β} {xs : Array α} {i : Nat} :
     (xs.mapIdx f)[i]? =
       xs[i]?.map (f i) := by
   simp [getElem?_def, size_mapIdx, getElem_mapIdx]
 
-@[simp] theorem toList_mapIdx {f : Nat → α → β} {xs : Array α} :
+@[simp, grind =] theorem toList_mapIdx {f : Nat → α → β} {xs : Array α} :
     (xs.mapIdx f).toList = xs.toList.mapIdx (fun i a => f i a) := by
   apply List.ext_getElem <;> simp
 
@@ -126,7 +126,7 @@ namespace Array
 
 /-! ### zipIdx -/
 
-@[simp] theorem getElem_zipIdx {xs : Array α} {k : Nat} {i : Nat} (h : i < (xs.zipIdx k).size) :
+@[simp, grind =] theorem getElem_zipIdx {xs : Array α} {k : Nat} {i : Nat} (h : i < (xs.zipIdx k).size) :
     (xs.zipIdx k)[i] = (xs[i]'(by simp_all), k + i) := by
   simp [zipIdx]
 
@@ -135,12 +135,12 @@ abbrev getElem_zipWithIndex := @getElem_zipIdx
 
 @[simp, grind =] theorem zipIdx_toArray {l : List α} {k : Nat} :
     l.toArray.zipIdx k = (l.zipIdx k).toArray := by
-  ext i hi₁ hi₂ <;> simp [Nat.add_comm]
+  ext i hi₁ hi₂ <;> simp
 
 @[deprecated zipIdx_toArray (since := "2025-01-21")]
 abbrev zipWithIndex_toArray := @zipIdx_toArray
 
-@[simp] theorem toList_zipIdx {xs : Array α} {k : Nat} :
+@[simp, grind =] theorem toList_zipIdx {xs : Array α} {k : Nat} :
     (xs.zipIdx k).toList = xs.toList.zipIdx k := by
   rcases xs with ⟨xs⟩
   simp
@@ -185,7 +185,7 @@ abbrev mem_zipWithIndex_iff_getElem? := @mem_zipIdx_iff_getElem?
   subst w
   rfl
 
-@[simp]
+@[simp, grind =]
 theorem mapFinIdx_empty {f : (i : Nat) → α → (h : i < 0) → β} : mapFinIdx #[] f = #[] :=
   rfl
 
@@ -195,6 +195,7 @@ theorem mapFinIdx_eq_ofFn {xs : Array α} {f : (i : Nat) → α → (h : i < xs.
   simp only [List.mapFinIdx_toArray, List.mapFinIdx_eq_ofFn, Fin.getElem_fin, List.getElem_toArray]
   simp [Array.size]
 
+@[grind =]
 theorem mapFinIdx_append {xs ys : Array α} {f : (i : Nat) → α → (h : i < (xs ++ ys).size) → β} :
     (xs ++ ys).mapFinIdx f =
       xs.mapFinIdx (fun i a h => f i a (by simp; omega)) ++
@@ -203,7 +204,7 @@ theorem mapFinIdx_append {xs ys : Array α} {f : (i : Nat) → α → (h : i < (
   cases ys
   simp [List.mapFinIdx_append, Array.size]
 
-@[simp]
+@[simp, grind =]
 theorem mapFinIdx_push {xs : Array α} {a : α} {f : (i : Nat) → α → (h : i < (xs.push a).size) → β} :
     mapFinIdx (xs.push a) f =
       (mapFinIdx xs (fun i a h => f i a (by simp; omega))).push (f xs.size a (by simp)) := by
@@ -237,7 +238,7 @@ theorem exists_of_mem_mapFinIdx {b : β} {xs : Array α} {f : (i : Nat) → α
   rcases xs with ⟨xs⟩
   exact List.exists_of_mem_mapFinIdx (by simpa using h)
 
-@[simp] theorem mem_mapFinIdx {b : β} {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
+@[simp, grind =] theorem mem_mapFinIdx {b : β} {xs : Array α} {f : (i : Nat) → α → (h : i < xs.size) → β} :
     b ∈ xs.mapFinIdx f ↔ ∃ (i : Nat) (h : i < xs.size), f i xs[i] h = b := by
   rcases xs with ⟨xs⟩
   simp
@@ -290,7 +291,7 @@ theorem mapFinIdx_eq_mapFinIdx_iff {xs : Array α} {f g : (i : Nat) → α → (
   rw [eq_comm, mapFinIdx_eq_iff]
   simp
 
-@[simp] theorem mapFinIdx_mapFinIdx {xs : Array α}
+@[simp, grind =] theorem mapFinIdx_mapFinIdx {xs : Array α}
     {f : (i : Nat) → α → (h : i < xs.size) → β}
     {g : (i : Nat) → β → (h : i < (xs.mapFinIdx f).size) → γ} :
     (xs.mapFinIdx f).mapFinIdx g = xs.mapFinIdx (fun i a h => g i (f i a h) (by simpa using h)) := by
@@ -305,14 +306,14 @@ theorem mapFinIdx_eq_replicate_iff {xs : Array α} {f : (i : Nat) → α → (h
 @[deprecated mapFinIdx_eq_replicate_iff (since := "2025-03-18")]
 abbrev mapFinIdx_eq_mkArray_iff := @mapFinIdx_eq_replicate_iff
 
-@[simp] theorem mapFinIdx_reverse {xs : Array α} {f : (i : Nat) → α → (h : i < xs.reverse.size) → β} :
+@[simp, grind =] theorem mapFinIdx_reverse {xs : Array α} {f : (i : Nat) → α → (h : i < xs.reverse.size) → β} :
     xs.reverse.mapFinIdx f = (xs.mapFinIdx (fun i a h => f (xs.size - 1 - i) a (by simp; omega))).reverse := by
   rcases xs with ⟨l⟩
   simp [List.mapFinIdx_reverse, Array.size]
 
 /-! ### mapIdx -/
 
-@[simp]
+@[simp, grind =]
 theorem mapIdx_empty {f : Nat → α → β} : mapIdx f #[] = #[] :=
   rfl
 
@@ -332,13 +333,14 @@ theorem mapIdx_eq_zipIdx_map {xs : Array α} {f : Nat → α → β} :
 @[deprecated mapIdx_eq_zipIdx_map (since := "2025-01-21")]
 abbrev mapIdx_eq_zipWithIndex_map := @mapIdx_eq_zipIdx_map
 
+@[grind =]
 theorem mapIdx_append {xs ys : Array α} :
     (xs ++ ys).mapIdx f = xs.mapIdx f ++ ys.mapIdx (fun i => f (i + xs.size)) := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
   simp [List.mapIdx_append]
 
-@[simp]
+@[simp, grind =]
 theorem mapIdx_push {xs : Array α} {a : α} :
     mapIdx f (xs.push a) = (mapIdx f xs).push (f xs.size a) := by
   simp [← append_singleton, mapIdx_append]
@@ -360,7 +362,7 @@ theorem exists_of_mem_mapIdx {b : β} {xs : Array α}
   rw [mapIdx_eq_mapFinIdx] at h
   simpa [Fin.exists_iff] using exists_of_mem_mapFinIdx h
 
-@[simp] theorem mem_mapIdx {b : β} {xs : Array α} :
+@[simp, grind =] theorem mem_mapIdx {b : β} {xs : Array α} :
     b ∈ mapIdx f xs ↔ ∃ (i : Nat) (h : i < xs.size), f i xs[i] = b := by
   constructor
   · intro h
@@ -414,7 +416,7 @@ theorem mapIdx_eq_mapIdx_iff {xs : Array α} :
   rcases xs with ⟨xs⟩
   simp [List.mapIdx_eq_mapIdx_iff]
 
-@[simp] theorem mapIdx_set {xs : Array α} {i : Nat} {h : i < xs.size} {a : α} :
+@[simp, grind =] theorem mapIdx_set {f : Nat → α → β} {xs : Array α} {i : Nat} {h : i < xs.size} {a : α} :
     (xs.set i a).mapIdx f = (xs.mapIdx f).set i (f i a) (by simpa) := by
   rcases xs with ⟨xs⟩
   simp [List.mapIdx_set]
@@ -424,17 +426,17 @@ theorem mapIdx_eq_mapIdx_iff {xs : Array α} :
   rcases xs with ⟨xs⟩
   simp [List.mapIdx_set]
 
-@[simp] theorem back?_mapIdx {xs : Array α} {f : Nat → α → β} :
+@[simp, grind =] theorem back?_mapIdx {xs : Array α} {f : Nat → α → β} :
     (mapIdx f xs).back? = (xs.back?).map (f (xs.size - 1)) := by
   rcases xs with ⟨xs⟩
   simp [List.getLast?_mapIdx]
 
-@[simp] theorem back_mapIdx {xs : Array α} {f : Nat → α → β} (h) :
+@[simp, grind =] theorem back_mapIdx {xs : Array α} {f : Nat → α → β} (h) :
     (xs.mapIdx f).back h = f (xs.size - 1) (xs.back (by simpa using h)) := by
   rcases xs with ⟨xs⟩
   simp [List.getLast_mapIdx]
 
-@[simp] theorem mapIdx_mapIdx {xs : Array α} {f : Nat → α → β} {g : Nat → β → γ} :
+@[simp, grind =] theorem mapIdx_mapIdx {xs : Array α} {f : Nat → α → β} {g : Nat → β → γ} :
     (xs.mapIdx f).mapIdx g = xs.mapIdx (fun i => g i ∘ f i) := by
   simp [mapIdx_eq_iff]
 
@@ -447,7 +449,7 @@ theorem mapIdx_eq_replicate_iff {xs : Array α} {f : Nat → α → β} {b : β}
 @[deprecated mapIdx_eq_replicate_iff (since := "2025-03-18")]
 abbrev mapIdx_eq_mkArray_iff := @mapIdx_eq_replicate_iff
 
-@[simp] theorem mapIdx_reverse {xs : Array α} {f : Nat → α → β} :
+@[simp, grind =] theorem mapIdx_reverse {xs : Array α} {f : Nat → α → β} :
     xs.reverse.mapIdx f = (mapIdx (fun i => f (xs.size - 1 - i)) xs).reverse := by
   rcases xs with ⟨xs⟩
   simp [List.mapIdx_reverse]
@@ -456,7 +458,7 @@ end Array
 
 namespace List
 
-@[grind] theorem mapFinIdxM_toArray [Monad m] [LawfulMonad m] {l : List α}
+@[grind =] theorem mapFinIdxM_toArray [Monad m] [LawfulMonad m] {l : List α}
     {f : (i : Nat) → α → (h : i < l.length) → m β} :
     l.toArray.mapFinIdxM f = toArray <$> l.mapFinIdxM f := by
   let rec go (i : Nat) (acc : Array β) (inv : i + acc.size = l.length) :
@@ -477,7 +479,7 @@ namespace List
   simp only [Array.mapFinIdxM, mapFinIdxM]
   exact go _ #[] _
 
-@[grind] theorem mapIdxM_toArray [Monad m] [LawfulMonad m] {l : List α}
+@[grind =] theorem mapIdxM_toArray [Monad m] [LawfulMonad m] {l : List α}
     {f : Nat → α → m β} :
     l.toArray.mapIdxM f = toArray <$> l.mapIdxM f := by
   let rec go (bs : List α) (acc : Array β) (inv : bs.length + acc.size = l.length) :

src/Init/Data/Array/Monadic.lean

@@ -36,19 +36,19 @@ theorem map_toList_inj [Monad m] [LawfulMonad m]
     xs.mapM (m := m) (pure <| f ·) = pure (xs.map f) := by
   induction xs; simp_all
 
-@[simp] theorem idRun_mapM {xs : Array α} {f : α → Id β} : (xs.mapM f).run = xs.map (f · |>.run) :=
+@[simp, grind =] theorem idRun_mapM {xs : Array α} {f : α → Id β} : (xs.mapM f).run = xs.map (f · |>.run) :=
   mapM_pure
 
 @[deprecated idRun_mapM (since := "2025-05-21")]
 theorem mapM_id {xs : Array α} {f : α → Id β} : xs.mapM f = xs.map f :=
   mapM_pure
 
-@[simp] theorem mapM_map [Monad m] [LawfulMonad m] {f : α → β} {g : β → m γ} {xs : Array α} :
+@[simp, grind =] theorem mapM_map [Monad m] [LawfulMonad m] {f : α → β} {g : β → m γ} {xs : Array α} :
     (xs.map f).mapM g = xs.mapM (g ∘ f) := by
   rcases xs with ⟨xs⟩
   simp
 
-@[simp] theorem mapM_append [Monad m] [LawfulMonad m] {f : α → m β} {xs ys : Array α} :
+@[simp, grind =] theorem mapM_append [Monad m] [LawfulMonad m] {f : α → m β} {xs ys : Array α} :
     (xs ++ ys).mapM f = (return (← xs.mapM f) ++ (← ys.mapM f)) := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
@@ -59,7 +59,7 @@ theorem mapM_eq_foldlM_push [Monad m] [LawfulMonad m] {f : α → m β} {xs : Ar
   rcases xs with ⟨xs⟩
   simp only [List.mapM_toArray, bind_pure_comp, List.size_toArray, List.foldlM_toArray']
   rw [List.mapM_eq_reverse_foldlM_cons]
-  simp only [bind_pure_comp, Functor.map_map]
+  simp only [Functor.map_map]
   suffices ∀ (l), (fun l' => l'.reverse.toArray) <$> List.foldlM (fun acc a => (fun a => a :: acc) <$> f a) l xs =
       List.foldlM (fun acc a => acc.push <$> f a) l.reverse.toArray xs by
     exact this []
@@ -143,13 +143,13 @@ theorem foldrM_filter [Monad m] [LawfulMonad m] {p : α → Bool} {g : α → β
   cases as <;> cases bs
   simp_all
 
-@[simp] theorem forM_append [Monad m] [LawfulMonad m] {xs ys : Array α} {f : α → m PUnit} :
+@[simp, grind =] theorem forM_append [Monad m] [LawfulMonad m] {xs ys : Array α} {f : α → m PUnit} :
     forM (xs ++ ys) f = (do forM xs f; forM ys f) := by
   rcases xs with ⟨xs⟩
   rcases ys with ⟨ys⟩
   simp
 
-@[simp] theorem forM_map [Monad m] [LawfulMonad m] {xs : Array α} {g : α → β} {f : β → m PUnit} :
+@[simp, grind =] theorem forM_map [Monad m] [LawfulMonad m] {xs : Array α} {g : α → β} {f : β → m PUnit} :
     forM (xs.map g) f = forM xs (fun a => f (g a)) := by
   rcases xs with ⟨xs⟩
   simp
@@ -208,7 +208,7 @@ theorem forIn'_yield_eq_foldl
       xs.attach.foldl (fun b ⟨a, h⟩ => f a h b) init :=
   forIn'_pure_yield_eq_foldl _ _
 
-@[simp] theorem forIn'_map [Monad m] [LawfulMonad m]
+@[simp, grind =] theorem forIn'_map [Monad m] [LawfulMonad m]
     {xs : Array α} (g : α → β) (f : (b : β) → b ∈ xs.map g → γ → m (ForInStep γ)) :
     forIn' (xs.map g) init f = forIn' xs init fun a h y => f (g a) (mem_map_of_mem h) y := by
   rcases xs with ⟨xs⟩
@@ -234,14 +234,14 @@ theorem forIn_eq_foldlM [Monad m] [LawfulMonad m]
     forIn xs init (fun a b => (fun c => .yield (g a b c)) <$> f a b) =
       xs.foldlM (fun b a => g a b <$> f a b) init := by
   rcases xs with ⟨xs⟩
-  simp [List.foldlM_map]
+  simp
 
 @[simp] theorem forIn_pure_yield_eq_foldl [Monad m] [LawfulMonad m]
     {xs : Array α} (f : α → β → β) (init : β) :
     forIn xs init (fun a b => pure (.yield (f a b))) =
       pure (f := m) (xs.foldl (fun b a => f a b) init) := by
   rcases xs with ⟨xs⟩
-  simp [List.forIn_pure_yield_eq_foldl, List.foldl_map]
+  simp [List.forIn_pure_yield_eq_foldl]
 
 theorem idRun_forIn_yield_eq_foldl
     {xs : Array α} (f : α → β → Id β) (init : β) :
@@ -256,7 +256,7 @@ theorem forIn_yield_eq_foldl
       xs.foldl (fun b a => f a b) init :=
   forIn_pure_yield_eq_foldl _ _
 
-@[simp] theorem forIn_map [Monad m] [LawfulMonad m]
+@[simp, grind =] theorem forIn_map [Monad m] [LawfulMonad m]
     {xs : Array α} {g : α → β} {f : β → γ → m (ForInStep γ)} :
     forIn (xs.map g) init f = forIn xs init fun a y => f (g a) y := by
   rcases xs with ⟨xs⟩

src/Init/Data/Array/OfFn.lean

@@ -23,7 +23,7 @@ namespace Array
 
 /-! ### ofFn -/
 
-@[simp] theorem ofFn_zero {f : Fin 0 → α} : ofFn f = #[] := by
+@[simp, grind =] theorem ofFn_zero {f : Fin 0 → α} : ofFn f = #[] := by
   simp [ofFn, ofFn.go]
 
 theorem ofFn_succ {f : Fin (n+1) → α} :
@@ -42,10 +42,10 @@ theorem ofFn_add {n m} {f : Fin (n + m) → α} :
   | zero => simp
   | succ m ih => simp [ofFn_succ, ih]
 
-@[simp] theorem _root_.List.toArray_ofFn {f : Fin n → α} : (List.ofFn f).toArray = Array.ofFn f := by
+@[simp, grind =] theorem _root_.List.toArray_ofFn {f : Fin n → α} : (List.ofFn f).toArray = Array.ofFn f := by
   ext <;> simp
 
-@[simp] theorem toList_ofFn {f : Fin n → α} : (Array.ofFn f).toList = List.ofFn f := by
+@[simp, grind =] theorem toList_ofFn {f : Fin n → α} : (Array.ofFn f).toList = List.ofFn f := by
   apply List.ext_getElem <;> simp
 
 theorem ofFn_succ' {f : Fin (n+1) → α} :
@@ -58,7 +58,7 @@ theorem ofFn_eq_empty_iff {f : Fin n → α} : ofFn f = #[] ↔ n = 0 := by
   rw [← Array.toList_inj]
   simp
 
-@[simp 500]
+@[simp 500, grind =]
 theorem mem_ofFn {n} {f : Fin n → α} {a : α} : a ∈ ofFn f ↔ ∃ i, f i = a := by
   constructor
   · intro w
@@ -73,7 +73,7 @@ theorem mem_ofFn {n} {f : Fin n → α} {a : α} : a ∈ ofFn f ↔ ∃ i, f i =
 def ofFnM {n} [Monad m] (f : Fin n → m α) : m (Array α) :=
   Fin.foldlM n (fun xs i => xs.push <$> f i) (Array.emptyWithCapacity n)
 
-@[simp]
+@[simp, grind =]
 theorem ofFnM_zero [Monad m] {f : Fin 0 → m α} : ofFnM f = pure #[] := by
   simp [ofFnM]
 
@@ -109,7 +109,7 @@ theorem ofFnM_add {n m} [Monad m] [LawfulMonad m] {f : Fin (n + k) → m α} :
     funext x
     simp
 
-@[simp] theorem toList_ofFnM [Monad m] [LawfulMonad m] {f : Fin n → m α} :
+@[simp, grind =] theorem toList_ofFnM [Monad m] [LawfulMonad m] {f : Fin n → m α} :
     toList <$> ofFnM f = List.ofFnM f := by
   induction n with
   | zero => simp

src/Init/Data/Array/Perm.lean

@@ -91,17 +91,26 @@ theorem Perm.mem_iff {a : α} {xs ys : Array α} (p : xs ~ ys) : a ∈ xs ↔ a
   simp only [perm_iff_toList_perm] at p
   simpa using p.mem_iff
 
+grind_pattern Perm.mem_iff => xs ~ ys, a ∈ xs
+grind_pattern Perm.mem_iff => xs ~ ys, a ∈ ys
+
 theorem Perm.append {xs ys as bs : Array α} (p₁ : xs ~ ys) (p₂ : as ~ bs) :
     xs ++ as ~ ys ++ bs := by
   cases xs; cases ys; cases as; cases bs
   simp only [append_toArray, perm_iff_toList_perm] at p₁ p₂ ⊢
   exact p₁.append p₂
 
+grind_pattern Perm.append => xs ~ ys, as ~ bs, xs ++ as
+grind_pattern Perm.append => xs ~ ys, as ~ bs, ys ++ bs
+
 theorem Perm.push (x : α) {xs ys : Array α} (p : xs ~ ys) :
     xs.push x ~ ys.push x := by
   rw [push_eq_append_singleton]
   exact p.append .rfl
 
+grind_pattern Perm.push => xs ~ ys, xs.push x
+grind_pattern Perm.push => xs ~ ys, ys.push x
+
 theorem Perm.push_comm (x y : α) {xs ys : Array α} (p : xs ~ ys) :
     (xs.push x).push y ~ (ys.push y).push x := by
   cases xs; cases ys

src/Init/Data/Array/Range.lean

@@ -29,6 +29,7 @@ open Nat
 
 /-! ### range' -/
 
+@[grind _=_]
 theorem range'_succ {s n step} : range' s (n + 1) step = #[s] ++ range' (s + step) n step := by
   rw [← toList_inj]
   simp [List.range'_succ]
@@ -39,16 +40,17 @@ theorem range'_succ {s n step} : range' s (n + 1) step = #[s] ++ range' (s + ste
 theorem range'_ne_empty_iff : range' s n step ≠ #[] ↔ n ≠ 0 := by
   cases n <;> simp
 
-@[simp] theorem range'_zero : range' s 0 step = #[] := by
+@[simp, grind =] theorem range'_zero : range' s 0 step = #[] := by
   simp
 
-@[simp] theorem range'_one {s step : Nat} : range' s 1 step = #[s] := by
+@[simp, grind =] theorem range'_one {s step : Nat} : range' s 1 step = #[s] := by
   simp [range', ofFn, ofFn.go]
 
 @[simp] theorem range'_inj : range' s n = range' s' n' ↔ n = n' ∧ (n = 0 ∨ s = s') := by
   rw [← toList_inj]
   simp [List.range'_inj]
 
+@[grind =]
 theorem mem_range' {n} : m ∈ range' s n step ↔ ∃ i < n, m = s + step * i := by
   simp [range']
   constructor
@@ -57,6 +59,7 @@ theorem mem_range' {n} : m ∈ range' s n step ↔ ∃ i < n, m = s + step * i :
   · rintro ⟨i, w, h'⟩
     exact ⟨⟨i, w⟩, by simp_all⟩
 
+@[simp, grind =]
 theorem pop_range' : (range' s n step).pop = range' s (n - 1) step := by
   ext <;> simp
 
@@ -66,6 +69,7 @@ theorem map_add_range' {a} (s n step) : map (a + ·) (range' s n step) = range'
 theorem range'_succ_left : range' (s + 1) n step = (range' s n step).map (· + 1) := by
   ext <;> simp <;> omega
 
+@[grind _=_]
 theorem range'_append {s m n step : Nat} :
     range' s m step ++ range' (s + step * m) n step = range' s (m + n) step := by
   ext i h₁ h₂
@@ -77,7 +81,8 @@ theorem range'_append {s m n step : Nat} :
     have : step * m ≤ step * i := by exact mul_le_mul_left step h
     omega
 
-@[simp] theorem range'_append_1 {s m n : Nat} :
+@[simp, grind _=_]
+theorem range'_append_1 {s m n : Nat} :
     range' s m ++ range' (s + m) n = range' s (m + n) := by simpa using range'_append (step := 1)
 
 theorem range'_concat {s n : Nat} : range' s (n + 1) step = range' s n step ++ #[s + step * n] := by
@@ -86,7 +91,7 @@ theorem range'_concat {s n : Nat} : range' s (n + 1) step = range' s n step ++ #
 theorem range'_1_concat {s n : Nat} : range' s (n + 1) = range' s n ++ #[s + n] := by
   simp [range'_concat]
 
-@[simp] theorem mem_range'_1 : m ∈ range' s n ↔ s ≤ m ∧ m < s + n := by
+@[simp, grind =] theorem mem_range'_1 : m ∈ range' s n ↔ s ≤ m ∧ m < s + n := by
   simp [mem_range']; exact ⟨
     fun ⟨i, h, e⟩ => e ▸ ⟨Nat.le_add_right .., Nat.add_lt_add_left h _⟩,
     fun ⟨h₁, h₂⟩ => ⟨m - s, Nat.sub_lt_left_of_lt_add h₁ h₂, (Nat.add_sub_cancel' h₁).symm⟩⟩
@@ -116,14 +121,26 @@ theorem range'_eq_append_iff : range' s n = xs ++ ys ↔ ∃ k, k ≤ n ∧ xs =
   simp only [List.find?_toArray]
   simp
 
+@[grind =]
 theorem erase_range' :
     (range' s n).erase i =
       range' s (min n (i - s)) ++ range' (max s (i + 1)) (min s (i + 1) + n - (i + 1)) := by
   simp only [← List.toArray_range', List.erase_toArray]
   simp [List.erase_range']
 
+@[simp, grind =]
+theorem count_range' {a s n step} (h : 0 < step := by simp) :
+    count a (range' s n step) = if ∃ i, i < n ∧ a = s + step * i then 1 else 0 := by
+  rw [← List.toArray_range', List.count_toArray, ← List.count_range' h]
+
+@[simp, grind =]
+theorem count_range_1' {a s n} :
+    count a (range' s n) = if s ≤ a ∧ a < s + n then 1 else 0 := by
+  rw [← List.toArray_range', List.count_toArray, ← List.count_range_1']
+
 /-! ### range -/
 
+@[grind _=_]
 theorem range_eq_range' {n : Nat} : range n = range' 0 n := by
   simp [range, range']
 
@@ -145,6 +162,7 @@ theorem range'_eq_map_range {s n : Nat} : range' s n = map (s + ·) (range n) :=
 theorem range_ne_empty_iff {n : Nat} : range n ≠ #[] ↔ n ≠ 0 := by
   cases n <;> simp
 
+@[grind _=_]
 theorem range_succ {n : Nat} : range (succ n) = range n ++ #[n] := by
   ext i h₁ h₂
   · simp
@@ -160,7 +178,7 @@ theorem range_add {n m : Nat} : range (n + m) = range n ++ (range m).map (n + ·
 theorem reverse_range' {s n : Nat} : reverse (range' s n) = map (s + n - 1 - ·) (range n) := by
   simp [← toList_inj, List.reverse_range']
 
-@[simp]
+@[simp, grind =]
 theorem mem_range {m n : Nat} : m ∈ range n ↔ m < n := by
   simp only [range_eq_range', mem_range'_1, Nat.zero_le, true_and, Nat.zero_add]
 
@@ -168,20 +186,25 @@ theorem not_mem_range_self {n : Nat} : n ∉ range n := by simp
 
 theorem self_mem_range_succ {n : Nat} : n ∈ range (n + 1) := by simp
 
-@[simp] theorem take_range {i n : Nat} : take (range n) i = range (min i n) := by
+@[simp, grind =] theorem take_range {i n : Nat} : take (range n) i = range (min i n) := by
   ext <;> simp
 
-@[simp] theorem find?_range_eq_some {n : Nat} {i : Nat} {p : Nat → Bool} :
+@[simp, grind =] theorem find?_range_eq_some {n : Nat} {i : Nat} {p : Nat → Bool} :
     (range n).find? p = some i ↔ p i ∧ i ∈ range n ∧ ∀ j, j < i → !p j := by
   simp [range_eq_range']
 
-@[simp] theorem find?_range_eq_none {n : Nat} {p : Nat → Bool} :
+@[simp, grind =] theorem find?_range_eq_none {n : Nat} {p : Nat → Bool} :
     (range n).find? p = none ↔ ∀ i, i < n → !p i := by
   simp only [← List.toArray_range, List.find?_toArray, List.find?_range_eq_none]
 
+@[grind =]
 theorem erase_range : (range n).erase i = range (min n i) ++ range' (i + 1) (n - (i + 1)) := by
   simp [range_eq_range', erase_range']
 
+@[simp, grind =]
+theorem count_range {a n} :
+    count a (range n) = if a < n then 1 else 0 := by
+  rw [← List.toArray_range, List.count_toArray, ← List.count_range]
 
 /-! ### zipIdx -/
 
@@ -190,13 +213,13 @@ theorem zipIdx_eq_empty_iff {xs : Array α} {i : Nat} : xs.zipIdx i = #[] ↔ xs
   cases xs
   simp
 
-@[simp]
+@[simp, grind =]
 theorem getElem?_zipIdx {xs : Array α} {i j} : (zipIdx xs i)[j]? = xs[j]?.map fun a => (a, i + j) := by
   simp [getElem?_def]
 
 theorem map_snd_add_zipIdx_eq_zipIdx {xs : Array α} {n k : Nat} :
     map (Prod.map id (· + n)) (zipIdx xs k) = zipIdx xs (n + k) :=
-  ext_getElem? fun i ↦ by simp [(· ∘ ·), Nat.add_comm, Nat.add_left_comm]; rfl
+  ext_getElem? fun i ↦ by simp [Nat.add_comm, Nat.add_left_comm]; rfl
 
 -- Arguments are explicit for parity with `zipIdx_map_fst`.
 @[simp]
@@ -233,7 +256,7 @@ theorem zipIdx_eq_map_add {xs : Array α} {i : Nat} :
   simp only [zipIdx_toArray, List.map_toArray, mk.injEq]
   rw [List.zipIdx_eq_map_add]
 
-@[simp]
+@[simp, grind =]
 theorem zipIdx_singleton {x : α} {k : Nat} : zipIdx #[x] k = #[(x, k)] :=
   rfl
 
@@ -281,6 +304,7 @@ theorem zipIdx_map {xs : Array α} {k : Nat} {f : α → β} :
   cases xs
   simp [List.zipIdx_map]
 
+@[grind =]
 theorem zipIdx_append {xs ys : Array α} {k : Nat} :
     zipIdx (xs ++ ys) k = zipIdx xs k ++ zipIdx ys (k + xs.size) := by
   cases xs

src/Init/Data/Array/Subarray.lean

@@ -7,6 +7,7 @@ module
 
 prelude
 import Init.Data.Array.Basic
+import Init.Data.Slice.Basic
 
 set_option linter.indexVariables true -- Enforce naming conventions for index variables.
 set_option linter.missingDocs true
@@ -14,14 +15,9 @@ set_option linter.missingDocs true
 universe u v w
 
 /--
-A region of some underlying array.
-
-A subarray contains an array together with the start and end indices of a region of interest.
-Subarrays can be used to avoid copying or allocating space, while being more convenient than
-tracking the bounds by hand. The region of interest consists of every index that is both greater
-than or equal to `start` and strictly less than `stop`.
+Internal representation of `Subarray`, which is an abbreviation for `Slice SubarrayData`.
 -/
-structure Subarray (α : Type u) where
+structure Std.Slice.Internal.SubarrayData (α : Type u) where
   /-- The underlying array. -/
   array : Array α
   /-- The starting index of the region of interest (inclusive). -/
@@ -42,6 +38,40 @@ structure Subarray (α : Type u) where
   -/
   stop_le_array_size : stop ≤ array.size
 
+open Std.Slice
+
+/--
+A region of some underlying array.
+
+A subarray contains an array together with the start and end indices of a region of interest.
+Subarrays can be used to avoid copying or allocating space, while being more convenient than
+tracking the bounds by hand. The region of interest consists of every index that is both greater
+than or equal to `start` and strictly less than `stop`.
+-/
+abbrev Subarray (α : Type u) := Std.Slice (Internal.SubarrayData α)
+
+instance {α : Type u} : Self (Std.Slice (Internal.SubarrayData α)) (Subarray α) where
+
+@[always_inline, inline, expose, inherit_doc Internal.SubarrayData.array]
+def Subarray.array (xs : Subarray α) : Array α :=
+  xs.internalRepresentation.array
+
+@[always_inline, inline, expose, inherit_doc Internal.SubarrayData.start]
+def Subarray.start (xs : Subarray α) : Nat :=
+  xs.internalRepresentation.start
+
+@[always_inline, inline, expose, inherit_doc Internal.SubarrayData.stop]
+def Subarray.stop (xs : Subarray α) : Nat :=
+  xs.internalRepresentation.stop
+
+@[always_inline, inline, expose, inherit_doc Internal.SubarrayData.start_le_stop]
+def Subarray.start_le_stop (xs : Subarray α) : xs.start ≤ xs.stop :=
+  xs.internalRepresentation.start_le_stop
+
+@[always_inline, inline, expose, inherit_doc Internal.SubarrayData.stop_le_array_size]
+def Subarray.stop_le_array_size (xs : Subarray α) : xs.stop ≤ xs.array.size :=
+  xs.internalRepresentation.stop_le_array_size
+
 namespace Subarray
 
 /--
@@ -51,7 +81,7 @@ def size (s : Subarray α) : Nat :=
   s.stop - s.start
 
 theorem size_le_array_size {s : Subarray α} : s.size ≤ s.array.size := by
-  let {array, start, stop, start_le_stop, stop_le_array_size} := s
+  let ⟨{array, start, stop, start_le_stop, stop_le_array_size}⟩ := s
   simp [size]
   apply Nat.le_trans (Nat.sub_le stop start)
   assumption
@@ -102,7 +132,9 @@ Examples:
 -/
 def popFront (s : Subarray α) : Subarray α :=
   if h : s.start < s.stop then
-    { s with start := s.start + 1, start_le_stop := Nat.le_of_lt_succ (Nat.add_lt_add_right h 1) }
+    ⟨{ s.internalRepresentation with
+        start := s.start + 1,
+        start_le_stop := Nat.le_of_lt_succ (Nat.add_lt_add_right h 1) }⟩
   else
     s
 
@@ -111,12 +143,13 @@ The empty subarray.
 
 This empty subarray is backed by an empty array.
 -/
-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
+protected def empty : Subarray α := ⟨{
+    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⟩
@@ -410,24 +443,24 @@ Additionally, the starting index is clamped to the ending index.
 def toSubarray (as : Array α) (start : Nat := 0) (stop : Nat := as.size) : Subarray α :=
   if h₂ : stop ≤ as.size then
     if h₁ : start ≤ stop then
-      { array := as, start := start, stop := stop,
-        start_le_stop := h₁, stop_le_array_size := h₂ }
+      ⟨{ array := as, start := start, stop := stop,
+         start_le_stop := h₁, stop_le_array_size := h₂ }⟩
     else
-      { array := as, start := stop, stop := stop,
-        start_le_stop := Nat.le_refl _, stop_le_array_size := h₂ }
+      ⟨{ array := as, start := stop, stop := stop,
+         start_le_stop := Nat.le_refl _, stop_le_array_size := h₂ }⟩
   else
     if h₁ : start ≤ as.size then
-      { array := as,
-        start := start,
-        stop := as.size,
-        start_le_stop := h₁,
-        stop_le_array_size := Nat.le_refl _ }
+      ⟨{ array := as,
+         start := start,
+         stop := as.size,
+         start_le_stop := h₁,
+         stop_le_array_size := Nat.le_refl _ }⟩
     else
-      { array := as,
-        start := as.size,
-        stop := as.size,
-        start_le_stop := Nat.le_refl _,
-        stop_le_array_size := Nat.le_refl _ }
+      ⟨{ array := as,
+         start := as.size,
+         stop := as.size,
+         start_le_stop := Nat.le_refl _,
+         stop_le_array_size := Nat.le_refl _ }⟩
 
 /--
 Allocates a new array that contains the contents of the subarray.

src/Init/Data/Array/Subarray/Split.lean

@@ -21,44 +21,24 @@ set_option linter.listVariables true -- Enforce naming conventions for `List`/`A
 set_option linter.indexVariables true -- Enforce naming conventions for index variables.
 
 namespace Subarray
-/--
-Splits a subarray into two parts, the first of which contains the first `i` elements and the second
-of which contains the remainder.
--/
-def split (s : Subarray α) (i : Fin s.size.succ) : (Subarray α × Subarray α) :=
-  let ⟨i', isLt⟩ := i
-  have := s.start_le_stop
-  have := s.stop_le_array_size
-  have : s.start + i' ≤ s.stop := by
-    simp only [size] at isLt
-    omega
-  let pre := {s with
-    stop := s.start + i',
-    start_le_stop := by omega,
-    stop_le_array_size := by omega
-  }
-  let post := {s with
-    start := s.start + i'
-    start_le_stop := by assumption
-  }
-  (pre, post)
 
 /--
 Removes the first `i` elements of the subarray. If there are `i` or fewer elements, the resulting
 subarray is empty.
 -/
-def drop (arr : Subarray α) (i : Nat) : Subarray α where
+def drop (arr : Subarray α) (i : Nat) : Subarray α := ⟨{
   array := arr.array
   start := min (arr.start + i) arr.stop
   stop := arr.stop
   start_le_stop := by omega
   stop_le_array_size := arr.stop_le_array_size
+}⟩
 
 /--
 Keeps only the first `i` elements of the subarray. If there are `i` or fewer elements, the resulting
 subarray is empty.
 -/
-def take (arr : Subarray α) (i : Nat) : Subarray α where
+def take (arr : Subarray α) (i : Nat) : Subarray α := ⟨{
   array := arr.array
   start := arr.start
   stop := min (arr.start + i) arr.stop
@@ -68,3 +48,11 @@ def take (arr : Subarray α) (i : Nat) : Subarray α where
   stop_le_array_size := by
     have := arr.stop_le_array_size
     omega
+}⟩
+
+/--
+Splits a subarray into two parts, the first of which contains the first `i` elements and the second
+of which contains the remainder.
+-/
+def split (s : Subarray α) (i : Fin s.size.succ) : (Subarray α × Subarray α) :=
+  (s.take i, s.drop i)

src/Init/Data/Array/Zip.lean

@@ -45,6 +45,7 @@ theorem zipWith_self {f : α → α → δ} {xs : Array α} : zipWith f xs xs =
 See also `getElem?_zipWith'` for a variant
 using `Option.map` and `Option.bind` rather than a `match`.
 -/
+@[grind =]
 theorem getElem?_zipWith {f : α → β → γ} {i : Nat} :
     (zipWith f as bs)[i]? = match as[i]?, bs[i]? with
       | some a, some b => some (f a b) | _, _ => none := by
@@ -76,31 +77,35 @@ theorem getElem?_zip_eq_some {as : Array α} {bs : Array β} {z : α × β} {i :
   · rintro ⟨h₀, h₁⟩
     exact ⟨_, _, h₀, h₁, rfl⟩
 
-@[simp]
+@[simp, grind =]
 theorem zipWith_map {μ} {f : γ → δ → μ} {g : α → γ} {h : β → δ} {as : Array α} {bs : Array β} :
     zipWith f (as.map g) (bs.map h) = zipWith (fun a b => f (g a) (h b)) as bs := by
   cases as
   cases bs
   simp [List.zipWith_map]
 
+@[grind =]
 theorem zipWith_map_left {as : Array α} {bs : Array β} {f : α → α'} {g : α' → β → γ} :
     zipWith g (as.map f) bs = zipWith (fun a b => g (f a) b) as bs := by
   cases as
   cases bs
   simp [List.zipWith_map_left]
 
+@[grind =]
 theorem zipWith_map_right {as : Array α} {bs : Array β} {f : β → β'} {g : α → β' → γ} :
     zipWith g as (bs.map f) = zipWith (fun a b => g a (f b)) as bs := by
   cases as
   cases bs
   simp [List.zipWith_map_right]
 
+@[grind =]
 theorem zipWith_foldr_eq_zip_foldr {f : α → β → γ} {i : δ} :
     (zipWith f as bs).foldr g i = (zip as bs).foldr (fun p r => g (f p.1 p.2) r) i := by
   cases as
   cases bs
   simp [List.zipWith_foldr_eq_zip_foldr]
 
+@[grind =]
 theorem zipWith_foldl_eq_zip_foldl {f : α → β → γ} {i : δ} :
     (zipWith f as bs).foldl g i = (zip as bs).foldl (fun r p => g r (f p.1 p.2)) i := by
   cases as
@@ -111,22 +116,26 @@ theorem zipWith_foldl_eq_zip_foldl {f : α → β → γ} {i : δ} :
 theorem zipWith_eq_empty_iff {f : α → β → γ} {as : Array α} {bs : Array β} : zipWith f as bs = #[] ↔ as = #[] ∨ bs = #[] := by
   cases as <;> cases bs <;> simp
 
+@[grind =]
 theorem map_zipWith {δ : Type _} {f : α → β} {g : γ → δ → α} {cs : Array γ} {ds : Array δ} :
     map f (zipWith g cs ds) = zipWith (fun x y => f (g x y)) cs ds := by
   cases cs
   cases ds
   simp [List.map_zipWith]
 
+@[grind =]
 theorem take_zipWith : (zipWith f as bs).take i = zipWith f (as.take i) (bs.take i) := by
   cases as
   cases bs
   simp [List.take_zipWith]
 
+@[grind =]
 theorem extract_zipWith : (zipWith f as bs).extract i j = zipWith f (as.extract i j) (bs.extract i j) := by
   cases as
   cases bs
   simp [List.drop_zipWith, List.take_zipWith]
 
+@[grind =]
 theorem zipWith_append {f : α → β → γ} {as as' : Array α} {bs bs' : Array β}
     (h : as.size = bs.size) :
     zipWith f (as ++ as') (bs ++ bs') = zipWith f as bs ++ zipWith f as' bs' := by
@@ -152,7 +161,7 @@ theorem zipWith_eq_append_iff {f : α → β → γ} {as : Array α} {bs : Array
   · rintro ⟨⟨ws⟩, ⟨xs⟩, ⟨ys⟩, ⟨zs⟩, h, rfl, rfl, h₁, h₂⟩
     exact ⟨ws, xs, ys, zs, by simp_all⟩
 
-@[simp] theorem zipWith_replicate {a : α} {b : β} {m n : Nat} :
+@[simp, grind =] theorem zipWith_replicate {a : α} {b : β} {m n : Nat} :
     zipWith f (replicate m a) (replicate n b) = replicate (min m n) (f a b) := by
   simp [← List.toArray_replicate]
 
@@ -184,6 +193,7 @@ theorem zipWith_eq_zipWith_take_min (as : Array α) (bs : Array β) :
   simp
   rw [List.zipWith_eq_zipWith_take_min]
 
+@[grind =]
 theorem reverse_zipWith (h : as.size = bs.size) :
     (zipWith f as bs).reverse = zipWith f as.reverse bs.reverse := by
   cases as
@@ -200,7 +210,7 @@ theorem lt_size_right_of_zip {i : Nat} {as : Array α} {bs : Array β} (h : i <
     i < bs.size :=
   lt_size_right_of_zipWith h
 
-@[simp]
+@[simp, grind =]
 theorem getElem_zip {as : Array α} {bs : Array β} {i : Nat} {h : i < (zip as bs).size} :
     (zip as bs)[i] =
       (as[i]'(lt_size_left_of_zip h), bs[i]'(lt_size_right_of_zip h)) :=
@@ -211,18 +221,22 @@ theorem zip_eq_zipWith {as : Array α} {bs : Array β} : zip as bs = zipWith Pro
   cases bs
   simp [List.zip_eq_zipWith]
 
+@[grind _=_]
 theorem zip_map {f : α → γ} {g : β → δ} {as : Array α} {bs : Array β} :
     zip (as.map f) (bs.map g) = (zip as bs).map (Prod.map f g) := by
   cases as
   cases bs
   simp [List.zip_map]
 
+@[grind _=_]
 theorem zip_map_left {f : α → γ} {as : Array α} {bs : Array β} :
     zip (as.map f) bs = (zip as bs).map (Prod.map f id) := by rw [← zip_map, map_id]
 
+@[grind _=_]
 theorem zip_map_right {f : β → γ} {as : Array α} {bs : Array β} :
     zip as (bs.map f) = (zip as bs).map (Prod.map id f) := by rw [← zip_map, map_id]
 
+@[grind =]
 theorem zip_append {as bs : Array α} {cs ds : Array β} (_h : as.size = cs.size) :
     zip (as ++ bs) (cs ++ ds) = zip as cs ++ zip bs ds := by
   cases as
@@ -231,6 +245,7 @@ theorem zip_append {as bs : Array α} {cs ds : Array β} (_h : as.size = cs.size
   cases ds
   simp_all [List.zip_append]
 
+@[grind =]
 theorem zip_map' {f : α → β} {g : α → γ} {xs : Array α} :
     zip (xs.map f) (xs.map g) = xs.map fun a => (f a, g a) := by
   cases xs
@@ -276,7 +291,7 @@ theorem zip_eq_append_iff {as : Array α} {bs : Array β} :
       ∃ as₁ as₂ bs₁ bs₂, as₁.size = bs₁.size ∧ as = as₁ ++ as₂ ∧ bs = bs₁ ++ bs₂ ∧ xs = zip as₁ bs₁ ∧ ys = zip as₂ bs₂ := by
   simp [zip_eq_zipWith, zipWith_eq_append_iff]
 
-@[simp] theorem zip_replicate {a : α} {b : β} {m n : Nat} :
+@[simp, grind =] theorem zip_replicate {a : α} {b : β} {m n : Nat} :
     zip (replicate m a) (replicate n b) = replicate (min m n) (a, b) := by
   simp [← List.toArray_replicate]
 
@@ -293,6 +308,7 @@ theorem zip_eq_zip_take_min {as : Array α} {bs : Array β} :
 
 /-! ### zipWithAll -/
 
+@[grind =]
 theorem getElem?_zipWithAll {f : Option α → Option β → γ} {i : Nat} :
     (zipWithAll f as bs)[i]? = match as[i]?, bs[i]? with
       | none, none => .none | a?, b? => some (f a? b?) := by
@@ -301,31 +317,35 @@ theorem getElem?_zipWithAll {f : Option α → Option β → γ} {i : Nat} :
   simp [List.getElem?_zipWithAll]
   rfl
 
+@[grind =]
 theorem zipWithAll_map {μ} {f : Option γ → Option δ → μ} {g : α → γ} {h : β → δ} {as : Array α} {bs : Array β} :
     zipWithAll f (as.map g) (bs.map h) = zipWithAll (fun a b => f (g <$> a) (h <$> b)) as bs := by
   cases as
   cases bs
   simp [List.zipWithAll_map]
 
+@[grind =]
 theorem zipWithAll_map_left {as : Array α} {bs : Array β} {f : α → α'} {g : Option α' → Option β → γ} :
     zipWithAll g (as.map f) bs = zipWithAll (fun a b => g (f <$> a) b) as bs := by
   cases as
   cases bs
   simp [List.zipWithAll_map_left]
 
+@[grind =]
 theorem zipWithAll_map_right {as : Array α} {bs : Array β} {f : β → β'} {g : Option α → Option β' → γ} :
     zipWithAll g as (bs.map f) = zipWithAll (fun a b => g a (f <$> b)) as bs := by
   cases as
   cases bs
   simp [List.zipWithAll_map_right]
 
+@[grind =]
 theorem map_zipWithAll {δ : Type _} {f : α → β} {g : Option γ → Option δ → α} {cs : Array γ} {ds : Array δ} :
     map f (zipWithAll g cs ds) = zipWithAll (fun x y => f (g x y)) cs ds := by
   cases cs
   cases ds
   simp [List.map_zipWithAll]
 
-@[simp] theorem zipWithAll_replicate {a : α} {b : β} {n : Nat} :
+@[simp, grind =] theorem zipWithAll_replicate {a : α} {b : β} {n : Nat} :
     zipWithAll f (replicate n a) (replicate n b) = replicate n (f (some a) (some b)) := by
   simp [← List.toArray_replicate]
 
@@ -342,6 +362,7 @@ theorem unzip_fst : (unzip l).fst = l.map Prod.fst := by
 theorem unzip_snd : (unzip l).snd = l.map Prod.snd := by
   simp
 
+@[grind =]
 theorem unzip_eq_map {xs : Array (α × β)} : unzip xs = (xs.map Prod.fst, xs.map Prod.snd) := by
   cases xs
   simp [List.unzip_eq_map]
@@ -375,9 +396,11 @@ theorem zip_of_prod {as : Array α} {bs : Array β} {xs : Array (α × β)} (hl
     (hr : xs.map Prod.snd = bs) : xs = as.zip bs := by
   rw [← hl, ← hr, ← zip_unzip xs, ← fst_unzip, ← snd_unzip, zip_unzip, zip_unzip]
 
-@[simp] theorem unzip_replicate {n : Nat} {a : α} {b : β} :
+@[simp, grind =] theorem unzip_replicate {n : Nat} {a : α} {b : β} :
     unzip (replicate n (a, b)) = (replicate n a, replicate n b) := by
   ext1 <;> simp
 
 @[deprecated unzip_replicate (since := "2025-03-18")]
 abbrev unzip_mkArray := @unzip_replicate
+
+end Array

src/Init/Data/BitVec.lean

@@ -6,7 +6,10 @@ Authors: Kim Morrison
 module
 
 prelude
+import Init.Data.BitVec.BasicAux
 import Init.Data.BitVec.Basic
+import Init.Data.BitVec.Bootstrap
 import Init.Data.BitVec.Bitblast
-import Init.Data.BitVec.Folds
+import Init.Data.BitVec.Decidable
 import Init.Data.BitVec.Lemmas
+import Init.Data.BitVec.Folds

src/Init/Data/BitVec/Basic.lean

@@ -37,7 +37,7 @@ instance natCastInst : NatCast (BitVec w) := ⟨BitVec.ofNat w⟩
 
 /-- Theorem for normalizing the bitvector literal representation. -/
 -- TODO: This needs more usage data to assess which direction the simp should go.
-@[simp, bitvec_to_nat] theorem ofNat_eq_ofNat : @OfNat.ofNat (BitVec n) i _ = .ofNat n i := rfl
+@[simp, bitvec_to_nat, grind =] theorem ofNat_eq_ofNat : @OfNat.ofNat (BitVec n) i _ = .ofNat n i := rfl
 
 -- Note. Mathlib would like this to go the other direction.
 @[simp] theorem natCast_eq_ofNat (w x : Nat) : @Nat.cast (BitVec w) _ x = .ofNat w x := rfl
@@ -74,25 +74,27 @@ section getXsb
 
 /--
 Returns the `i`th least significant bit.
-
-This will be renamed `getLsb` after the existing deprecated alias is removed.
 -/
-@[inline, expose] def getLsb' (x : BitVec w) (i : Fin w) : Bool := x.toNat.testBit i
+@[inline, expose] def getLsb (x : BitVec w) (i : Fin w) : Bool := x.toNat.testBit i
+
+@[deprecated getLsb (since := "2025-06-17"), inherit_doc getLsb]
+abbrev getLsb' := @getLsb
 
 /-- Returns the `i`th least significant bit, or `none` if `i ≥ w`. -/
 @[inline, expose] def getLsb? (x : BitVec w) (i : Nat) : Option Bool :=
-  if h : i < w then some (getLsb' x ⟨i, h⟩) else none
+  if h : i < w then some (getLsb x ⟨i, h⟩) else none
 
 /--
 Returns the `i`th most significant bit.
-
-This will be renamed `BitVec.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⟩
+@[inline] def getMsb (x : BitVec w) (i : Fin w) : Bool := x.getLsb ⟨w-1-i, by omega⟩
+
+@[deprecated getMsb (since := "2025-06-17"), inherit_doc getMsb]
+abbrev getMsb' := @getMsb
 
 /-- Returns the `i`th most significant bit or `none` if `i ≥ w`. -/
 @[inline] def getMsb? (x : BitVec w) (i : Nat) : Option Bool :=
-  if h : i < w then some (getMsb' x ⟨i, h⟩) else none
+  if h : i < w then some (getMsb x ⟨i, h⟩) else none
 
 /-- Returns the `i`th least significant bit or `false` if `i ≥ w`. -/
 @[inline, expose] def getLsbD (x : BitVec w) (i : Nat) : Bool :=
@@ -110,20 +112,21 @@ end getXsb
 section getElem
 
 instance : GetElem (BitVec w) Nat Bool fun _ i => i < w where
-  getElem xs i h := xs.getLsb' ⟨i, h⟩
+  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
+@[simp, grind =] 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) :
+@[simp, grind =] theorem getLsb?_eq_getElem? (x : BitVec w) (i : Nat) :
     x.getLsb? i = x[i]? := rfl
 
+@[grind =_] -- Activate when we see `x.toNat.testBit i`.
 theorem getElem_eq_testBit_toNat (x : BitVec w) (i : Nat) (h : i < w) :
   x[i] = x.toNat.testBit i := rfl
 
-@[simp]
+@[simp, grind =]
 theorem getLsbD_eq_getElem {x : BitVec w} {i : Nat} (h : i < w) :
     x.getLsbD i = x[i] := rfl
 
@@ -174,7 +177,7 @@ recommended_spelling "zero" for "0#n" in [BitVec.ofNat, «term__#__»]
 recommended_spelling "one" for "1#n" in [BitVec.ofNat, «term__#__»]
 
 /-- Unexpander for bitvector literals. -/
-@[app_unexpander BitVec.ofNat] def unexpandBitVecOfNat : Lean.PrettyPrinter.Unexpander
+@[app_unexpander BitVec.ofNat] meta def unexpandBitVecOfNat : Lean.PrettyPrinter.Unexpander
   | `($(_) $n $i:num) => `($i:num#$n)
   | _ => throw ()
 
@@ -183,7 +186,7 @@ scoped syntax:max term:max noWs "#'" noWs term:max : term
 macro_rules | `($i#'$p) => `(BitVec.ofNatLT $i $p)
 
 /-- Unexpander for bitvector literals without truncation. -/
-@[app_unexpander BitVec.ofNatLT] def unexpandBitVecOfNatLt : Lean.PrettyPrinter.Unexpander
+@[app_unexpander BitVec.ofNatLT] meta def unexpandBitVecOfNatLt : Lean.PrettyPrinter.Unexpander
   | `($(_) $i $p) => `($i#'$p)
   | _ => throw ()
 
@@ -354,8 +357,8 @@ section bool
 @[expose]
 def ofBool (b : Bool) : BitVec 1 := cond b 1 0
 
-@[simp] theorem ofBool_false : ofBool false = 0 := by trivial
-@[simp] theorem ofBool_true  : ofBool true  = 1 := by trivial
+@[simp, grind =] theorem ofBool_false : ofBool false = 0 := by trivial
+@[simp, grind =] theorem ofBool_true  : ofBool true  = 1 := by trivial
 
 /-- Fills a bitvector with `w` copies of the bit `b`. -/
 def fill (w : Nat) (b : Bool) : BitVec w := bif b then -1 else 0
@@ -413,15 +416,15 @@ that can more consistently simplify `BitVec.cast` away.
 -/
 @[inline, expose] protected def cast (eq : n = m) (x : BitVec n) : BitVec m := .ofNatLT x.toNat (eq ▸ x.isLt)
 
-@[simp] theorem cast_ofNat {n m : Nat} (h : n = m) (x : Nat) :
+@[simp, grind =] theorem cast_ofNat {n m : Nat} (h : n = m) (x : Nat) :
     (BitVec.ofNat n x).cast h = BitVec.ofNat m x := by
   subst h; rfl
 
-@[simp] theorem cast_cast {n m k : Nat} (h₁ : n = m) (h₂ : m = k) (x : BitVec n) :
+@[simp, grind =] theorem cast_cast {n m k : Nat} (h₁ : n = m) (h₂ : m = k) (x : BitVec n) :
     (x.cast h₁).cast h₂ = x.cast (h₁ ▸ h₂) :=
   rfl
 
-@[simp] theorem cast_eq {n : Nat} (h : n = n) (x : BitVec n) : x.cast h = x := rfl
+@[simp, grind =] theorem cast_eq {n : Nat} (h : n = n) (x : BitVec n) : x.cast h = x := rfl
 
 /--
 Extracts the bits `start` to `start + len - 1` from a bitvector of size `n` to yield a
@@ -705,10 +708,12 @@ The new bit is the most significant bit.
 def cons {n} (msb : Bool) (lsbs : BitVec n) : BitVec (n+1) :=
   ((ofBool msb) ++ lsbs).cast (Nat.add_comm ..)
 
+@[grind =]
 theorem append_ofBool (msbs : BitVec w) (lsb : Bool) :
     msbs ++ ofBool lsb = concat msbs lsb :=
   rfl
 
+@[grind =]
 theorem ofBool_append (msb : Bool) (lsbs : BitVec w) :
     ofBool msb ++ lsbs = (cons msb lsbs).cast (Nat.add_comm ..) :=
   rfl
@@ -723,6 +728,12 @@ def twoPow (w : Nat) (i : Nat) : BitVec w := 1#w <<< i
 
 end bitwise
 
+/-- The bitvector of width `w` that has the smallest value when interpreted as an integer. -/
+def intMin (w : Nat) := twoPow w (w - 1)
+
+/-- The bitvector of width `w` that has the largest value when interpreted as an integer. -/
+def intMax (w : Nat) := (twoPow w (w - 1)) - 1
+
 /--
 Computes a hash of a bitvector, combining 64-bit words using `mixHash`.
 -/
@@ -737,20 +748,20 @@ instance : Hashable (BitVec n) where
 
 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
-@[simp] theorem shiftLeft_eq (x : BitVec w) (n : Nat)     : BitVec.shiftLeft x n = x <<< n    := rfl
-@[simp] theorem ushiftRight_eq (x : BitVec w) (n : Nat)   : BitVec.ushiftRight x n = x >>> n  := rfl
-@[simp] theorem not_eq (x : BitVec w)                     : BitVec.not x = ~~~x               := rfl
-@[simp] theorem and_eq (x y : BitVec w)                   : BitVec.and x y = x &&& y          := rfl
-@[simp] theorem or_eq (x y : BitVec w)                    : BitVec.or x y = x ||| y           := rfl
-@[simp] theorem xor_eq (x y : BitVec w)                   : BitVec.xor x y = x ^^^ y          := rfl
-@[simp] theorem neg_eq (x : BitVec w)                     : BitVec.neg x = -x                 := rfl
-@[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
+@[simp, grind =] theorem append_eq (x : BitVec w) (y : BitVec v) : BitVec.append x y = x ++ y        := rfl
+@[simp, grind =] theorem shiftLeft_eq (x : BitVec w) (n : Nat)     : BitVec.shiftLeft x n = x <<< n    := rfl
+@[simp, grind =] theorem ushiftRight_eq (x : BitVec w) (n : Nat)   : BitVec.ushiftRight x n = x >>> n  := rfl
+@[simp, grind =] theorem not_eq (x : BitVec w)                     : BitVec.not x = ~~~x               := rfl
+@[simp, grind =] theorem and_eq (x y : BitVec w)                   : BitVec.and x y = x &&& y          := rfl
+@[simp, grind =] theorem or_eq (x y : BitVec w)                    : BitVec.or x y = x ||| y           := rfl
+@[simp, grind =] theorem xor_eq (x y : BitVec w)                   : BitVec.xor x y = x ^^^ y          := rfl
+@[simp, grind =] theorem neg_eq (x : BitVec w)                     : BitVec.neg x = -x                 := rfl
+@[simp, grind =] theorem add_eq (x y : BitVec w)                   : BitVec.add x y = x + y            := rfl
+@[simp, grind =] theorem sub_eq (x y : BitVec w)                   : BitVec.sub x y = x - y            := rfl
+@[simp, grind =] theorem mul_eq (x y : BitVec w)                   : BitVec.mul x y = x * y            := rfl
+@[simp, grind =] theorem udiv_eq (x y : BitVec w)                  : BitVec.udiv x y = x / y           := rfl
+@[simp, grind =] theorem umod_eq (x y : BitVec w)                  : BitVec.umod x y = x % y           := rfl
+@[simp, grind =] theorem zero_eq                                   : BitVec.zero n = 0#n               := rfl
 end normalization_eqs
 
 /-- Converts a list of `Bool`s into a big-endian `BitVec`. -/
@@ -842,4 +853,15 @@ treating `x` and `y` as 2's complement signed bitvectors.
 def smulOverflow {w : Nat} (x y : BitVec w) : Bool :=
   (x.toInt * y.toInt ≥ 2 ^ (w - 1)) || (x.toInt * y.toInt < - 2 ^ (w - 1))
 
+/-- Count the number of leading zeros downward from the `n`-th bit to the `0`-th bit for the bitblaster.
+  This builds a tree of `if-then-else` lookups whose length is linear in the bitwidth,
+  and an efficient circuit for bitblasting `clz`. -/
+def clzAuxRec {w : Nat} (x : BitVec w) (n : Nat) : BitVec w :=
+  match n with
+  | 0 => if x.getLsbD 0 then BitVec.ofNat w (w - 1) else BitVec.ofNat w w
+  | n' + 1 => if x.getLsbD n then BitVec.ofNat w (w - 1 - n) else clzAuxRec x n'
+
+/-- Count the number of leading zeros. -/
+def clz (x : BitVec w) : BitVec w := clzAuxRec x (w - 1)
+
 end BitVec

src/Init/Data/BitVec/BasicAux.lean

@@ -31,6 +31,8 @@ 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
 
+grind_pattern isLt => x.toNat, 2^w
+
 end Nat
 
 section arithmetic

src/Init/Data/BitVec/Bitblast.lean

@@ -6,12 +6,14 @@ Authors: Harun Khan, Abdalrhman M Mohamed, Joe Hendrix, Siddharth Bhat
 module
 
 prelude
-import Init.Data.BitVec.Folds
 import all Init.Data.Nat.Bitwise.Basic
 import Init.Data.Nat.Mod
 import all Init.Data.Int.DivMod
 import Init.Data.Int.LemmasAux
-import all Init.Data.BitVec.Lemmas
+import all Init.Data.BitVec.Basic
+import Init.Data.BitVec.Decidable
+import Init.Data.BitVec.Lemmas
+import Init.Data.BitVec.Folds
 
 /-!
 # Bit blasting of bitvectors
@@ -238,7 +240,7 @@ theorem toNat_add_of_and_eq_zero {x y : BitVec w} (h : x &&& y = 0#w) :
     simp only [decide_eq_true_eq] at this
     omega
   rw [← carry_width]
-  simp [not_eq_true, carry_of_and_eq_zero h]
+  simp [carry_of_and_eq_zero h]
 
 /-- Carry function for bitwise addition. -/
 def adcb (x y c : Bool) : Bool × Bool := (atLeastTwo x y c, x ^^ (y ^^ c))
@@ -252,7 +254,7 @@ theorem getLsbD_add_add_bool {i : Nat} (i_lt : i < w) (x y : BitVec w) (c : Bool
       (getLsbD x i ^^ (getLsbD y i ^^ carry i x y c)) := by
   let ⟨x, x_lt⟩ := x
   let ⟨y, y_lt⟩ := y
-  simp only [getLsbD, toNat_add, toNat_setWidth, i_lt, toNat_ofFin, toNat_ofBool,
+  simp only [getLsbD, toNat_add, toNat_setWidth, toNat_ofFin, toNat_ofBool,
     Nat.mod_add_mod, Nat.add_mod_mod]
   apply Eq.trans
   rw [← Nat.div_add_mod x (2^i), ← Nat.div_add_mod y (2^i)]
@@ -295,7 +297,7 @@ theorem adc_spec (x y : BitVec w) (c : Bool) :
     simp [carry, Nat.mod_one]
     cases c <;> rfl
   case step =>
-    simp [adcb, Prod.mk.injEq, carry_succ, getElem_add_add_bool]
+    simp [adcb, carry_succ, getElem_add_add_bool]
 
 theorem add_eq_adc (w : Nat) (x y : BitVec w) : x + y = (adc x y false).snd := by
   simp [adc_spec]
@@ -312,7 +314,7 @@ theorem msb_add {w : Nat} {x y: BitVec w} :
       Bool.xor x.msb (Bool.xor y.msb (carry (w - 1) x y false)) := by
   simp only [BitVec.msb, BitVec.getMsbD]
   by_cases h : w ≤ 0
-  · simp [h, show w = 0 by omega]
+  · simp [show w = 0 by omega]
   · rw [getLsbD_add (x := x)]
     simp [show w > 0 by omega]
     omega
@@ -332,15 +334,15 @@ theorem add_eq_or_of_and_eq_zero {w : Nat} (x y : BitVec w)
     (h : x &&& y = 0#w) : x + y = x ||| y := by
   rw [add_eq_adc, adc, iunfoldr_replace (fun _ => false) (x ||| y)]
   · rfl
-  · simp only [adcb, atLeastTwo, Bool.and_false, Bool.or_false, bne_false, getLsbD_or,
+  · simp only [adcb, atLeastTwo, Bool.and_false, Bool.or_false, bne_false, 
     Prod.mk.injEq, and_eq_false_imp]
     intros i
     replace h : (x &&& y).getLsbD i = (0#w).getLsbD i := by rw [h]
     simp only [getLsbD_and, getLsbD_zero, and_eq_false_imp] at h
     constructor
     · intros hx
-      simp_all [hx]
-    · by_cases hx : x.getLsbD i <;> simp_all [hx]
+      simp_all
+    · by_cases hx : x.getLsbD i <;> simp_all
 
 /-! ### Sub-/
 
@@ -377,7 +379,7 @@ theorem bit_not_add_self (x : BitVec w) :
   simp only [add_eq_adc]
   apply iunfoldr_replace_snd (fun _ => false) (-1) false rfl
   intro i; simp only [adcb, Fin.is_lt, getLsbD_eq_getElem, atLeastTwo_false_right, bne_false,
-    ofNat_eq_ofNat, Fin.getElem_fin, Prod.mk.injEq, and_eq_false_imp]
+    ofNat_eq_ofNat, Prod.mk.injEq, and_eq_false_imp]
   rw [iunfoldr_replace_snd (fun _ => ()) (((iunfoldr (fun i c => (c, !(x[i.val])))) ()).snd)]
   <;> simp [bit_not_testBit, neg_one_eq_allOnes, getElem_allOnes]
 
@@ -409,7 +411,7 @@ theorem getLsbD_neg {i : Nat} {x : BitVec w} :
   · rw [getLsbD_add hi]
     have : 0 < w := by omega
     simp only [getLsbD_not, hi, decide_true, Bool.true_and, getLsbD_one, this, not_bne,
-      _root_.true_and, not_eq_eq_eq_not]
+      not_eq_eq_eq_not]
     cases i with
     | zero =>
       have carry_zero : carry 0 ?x ?y false = false := by
@@ -424,7 +426,7 @@ theorem getLsbD_neg {i : Nat} {x : BitVec w} :
       · rintro h j hj; exact And.right <| h j (by omega)
       · rintro h j hj; exact ⟨by omega, h j (by omega)⟩
   · have h_ge : w ≤ i := by omega
-    simp [getLsbD_of_ge _ _ h_ge, h_ge, hi]
+    simp [h_ge, hi]
 
 theorem getElem_neg {i : Nat} {x : BitVec w} (h : i < w) :
     (-x)[i] = (x[i] ^^ decide (∃ j < i, x.getLsbD j = true)) := by
@@ -433,7 +435,7 @@ theorem getElem_neg {i : Nat} {x : BitVec w} (h : i < w) :
 theorem getMsbD_neg {i : Nat} {x : BitVec w} :
     getMsbD (-x) i =
       (getMsbD x i ^^ decide (∃ j < w, i < j ∧ getMsbD x j = true)) := by
-  simp only [getMsbD, getLsbD_neg, Bool.decide_and, Bool.and_eq_true, decide_eq_true_eq]
+  simp only [getMsbD, getLsbD_neg, Bool.and_eq_true, decide_eq_true_eq]
   by_cases hi : i < w
   case neg =>
     simp [hi]; omega
@@ -518,14 +520,11 @@ theorem msb_neg {w : Nat} {x : BitVec w} :
   rw [(show w = w - 1 + 1 by omega), Int.pow_succ] at this
   omega
 
-@[simp] theorem setWidth_neg_of_le {x : BitVec v} (h : w ≤ v) : BitVec.setWidth w (-x) = -BitVec.setWidth w x := by
-  simp [← BitVec.signExtend_eq_setWidth_of_le _ h, BitVec.signExtend_neg_of_le h]
-
 /-! ### abs -/
 
 theorem msb_abs {w : Nat} {x : BitVec w} :
     x.abs.msb = (decide (x = intMin w) && decide (0 < w)) := by
-  simp only [BitVec.abs, getMsbD_neg, ne_eq, decide_not, Bool.not_bne]
+  simp only [BitVec.abs]
   by_cases h₀ : 0 < w
   · by_cases h₁ : x = intMin w
     · simp [h₁, msb_intMin]
@@ -548,54 +547,14 @@ theorem ult_eq_not_carry (x y : BitVec w) : x.ult y = !carry w x (~~~y) true :=
   rw [Nat.mod_eq_of_lt (by omega)]
   omega
 
-theorem ule_eq_not_ult (x y : BitVec w) : x.ule y = !y.ult x := by
-  simp [BitVec.ule, BitVec.ult, ← decide_not]
-
 theorem ule_eq_carry (x y : BitVec w) : x.ule y = carry w y (~~~x) true := by
   simp [ule_eq_not_ult, ult_eq_not_carry]
 
-/-- If two bitvectors have the same `msb`, then signed and unsigned comparisons coincide -/
-theorem slt_eq_ult_of_msb_eq {x y : BitVec w} (h : x.msb = y.msb) :
-    x.slt y = x.ult y := by
-  simp only [BitVec.slt, toInt_eq_msb_cond, BitVec.ult, decide_eq_decide, h]
-  cases y.msb <;> simp
-
-/-- If two bitvectors have different `msb`s, then unsigned comparison is determined by this bit -/
-theorem ult_eq_msb_of_msb_neq {x y : BitVec w} (h : x.msb ≠ y.msb) :
-    x.ult y = y.msb := by
-  simp only [BitVec.ult, msb_eq_decide, ne_eq, decide_eq_decide] at *
-  omega
-
-/-- If two bitvectors have different `msb`s, then signed and unsigned comparisons are opposites -/
-theorem slt_eq_not_ult_of_msb_neq {x y : BitVec w} (h : x.msb ≠ y.msb) :
-    x.slt y = !x.ult y := by
-  simp only [BitVec.slt, toInt_eq_msb_cond, Bool.eq_not_of_ne h, ult_eq_msb_of_msb_neq h]
-  cases y.msb <;> (simp [-Int.natCast_pow]; omega)
-
-theorem slt_eq_ult {x y : BitVec w} :
-    x.slt y = (x.msb != y.msb).xor (x.ult y) := by
-  by_cases h : x.msb = y.msb
-  · simp [h, slt_eq_ult_of_msb_eq]
-  · have h' : x.msb != y.msb := by simp_all
-    simp [slt_eq_not_ult_of_msb_neq h, h']
-
 theorem slt_eq_not_carry {x y : BitVec w} :
     x.slt y = (x.msb == y.msb).xor (carry w x (~~~y) true) := by
   simp only [slt_eq_ult, bne, ult_eq_not_carry]
   cases x.msb == y.msb <;> simp
 
-theorem sle_eq_not_slt {x y : BitVec w} : x.sle y = !y.slt x := by
-  simp only [BitVec.sle, BitVec.slt, ← decide_not, decide_eq_decide]; omega
-
-theorem zero_sle_eq_not_msb {w : Nat} {x : BitVec w} : BitVec.sle 0#w x = !x.msb := by
-  rw [sle_eq_not_slt, BitVec.slt_zero_eq_msb]
-
-theorem zero_sle_iff_msb_eq_false {w : Nat} {x : BitVec w} : BitVec.sle 0#w x ↔ x.msb = false := by
-  simp [zero_sle_eq_not_msb]
-
-theorem toNat_toInt_of_sle {w : Nat} {x : BitVec w} (hx : BitVec.sle 0#w x) : x.toInt.toNat = x.toNat :=
-  toNat_toInt_of_msb x (zero_sle_iff_msb_eq_false.1 hx)
-
 theorem sle_eq_carry {x y : BitVec w} :
     x.sle y = !((x.msb == y.msb).xor (carry w y (~~~x) true)) := by
   rw [sle_eq_not_slt, slt_eq_not_carry, beq_comm]
@@ -618,12 +577,6 @@ theorem neg_sle_zero (h : 0 < w) {x : BitVec w} :
   rw [sle_eq_slt_or_eq, neg_slt_zero h, sle_eq_slt_or_eq]
   simp [Bool.beq_eq_decide_eq (-x), Bool.beq_eq_decide_eq _ x, Eq.comm (a := x), Bool.or_assoc]
 
-theorem sle_eq_ule {x y : BitVec w} : x.sle y = (x.msb != y.msb ^^ x.ule y) := by
-  rw [sle_eq_not_slt, slt_eq_ult, ← Bool.xor_not, ← ule_eq_not_ult, bne_comm]
-
-theorem sle_eq_ule_of_msb_eq {x y : BitVec w} (h : x.msb = y.msb) : x.sle y = x.ule y := by
-  simp [BitVec.sle_eq_ule, h]
-
 /-! ### mul recurrence for bit blasting -/
 
 /--
@@ -658,7 +611,7 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_add_twoPow (x : BitVec w) (i
       getElem_twoPow]
     by_cases hik : i = k
     · subst hik
-      simp [h]
+      simp
     · by_cases hik' : k < (i + 1)
       · have hik'' : k < i := by omega
         simp [hik', hik'']
@@ -667,8 +620,8 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_add_twoPow (x : BitVec w) (i
         simp [hik', hik'']
         omega
   · ext k
-    simp only [and_twoPow, getLsbD_and, getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and,
-      getLsbD_zero, and_eq_false_imp, and_eq_true, decide_eq_true_eq, and_imp]
+    simp only [and_twoPow, 
+      ]
     by_cases hi : x.getLsbD i <;> simp [hi] <;> omega
 
 /--
@@ -825,7 +778,7 @@ private theorem Nat.div_add_eq_left_of_lt {x y z : Nat} (hx : z ∣ x) (hy : y <
   · apply Nat.le_trans
     · exact div_mul_le_self x z
     · omega
-  · simp only [succ_eq_add_one, Nat.add_mul, Nat.one_mul]
+  · simp only [Nat.add_mul, Nat.one_mul]
     apply Nat.add_lt_add_of_le_of_lt
     · apply Nat.le_of_eq
       exact (Nat.div_eq_iff_eq_mul_left hz hx).mp rfl
@@ -938,10 +891,10 @@ def DivModState.lawful_init {w : Nat} (args : DivModArgs w) (hd : 0#w < args.d)
     hwrn := by simp only; omega,
     hdPos := by assumption
     hrLtDivisor := by simp [BitVec.lt_def] at hd ⊢; assumption
-    hrWidth := by simp [DivModState.init],
-    hqWidth := by simp [DivModState.init],
+    hrWidth := by simp,
+    hqWidth := by simp,
     hdiv := by
-      simp only [DivModState.init, toNat_ofNat, zero_mod, Nat.mul_zero, Nat.add_zero];
+      simp only [toNat_ofNat, zero_mod, Nat.mul_zero, Nat.add_zero];
       rw [Nat.shiftRight_eq_div_pow]
       apply Nat.div_eq_of_lt args.n.isLt
   }
@@ -969,7 +922,7 @@ theorem DivModState.umod_eq_of_lawful {qr : DivModState w}
     n % d = qr.r := by
   apply umod_eq_of_mul_add_toNat h.hrLtDivisor
   have hdiv := h.hdiv
-  simp only [shiftRight_zero] at hdiv
+  simp only at hdiv
   simp only [h_final] at *
   exact hdiv.symm
 
@@ -1023,7 +976,7 @@ theorem DivModState.toNat_shiftRight_sub_one_eq
     {args : DivModArgs w} {qr : DivModState w} (h : qr.Poised args) :
     args.n.toNat >>> (qr.wn - 1)
     = (args.n.toNat >>> qr.wn) * 2 + (args.n.getLsbD (qr.wn - 1)).toNat := by
-  show BitVec.toNat (args.n >>> (qr.wn - 1)) = _
+  change BitVec.toNat (args.n >>> (qr.wn - 1)) = _
   have {..} := h -- break the structure down for `omega`
   rw [shiftRight_sub_one_eq_shiftConcat args.n h.hwn_lt]
   rw [toNat_shiftConcat_eq_of_lt (k := w - qr.wn)]
@@ -1047,7 +1000,7 @@ obeys the division equation. -/
 theorem lawful_divSubtractShift (qr : DivModState w) (h : qr.Poised args) :
     DivModState.Lawful args (divSubtractShift args qr) := by
   rcases args with ⟨n, d⟩
-  simp only [divSubtractShift, decide_eq_true_eq]
+  simp only [divSubtractShift]
   -- We add these hypotheses for `omega` to find them later.
   have ⟨⟨hrwn, hd, hrd, hr, hn, hrnd⟩, hwn_lt⟩ := h
   have : d.toNat * (qr.q.toNat * 2) = d.toNat * qr.q.toNat * 2 := by rw [Nat.mul_assoc]
@@ -1184,7 +1137,7 @@ theorem getLsbD_udiv (n d : BitVec w) (hy : 0#w < d)  (i : Nat) :
 
 theorem getMsbD_udiv (n d : BitVec w) (hd : 0#w < d)  (i : Nat) :
     (n / d).getMsbD i = (decide (i < w) && (divRec w {n, d} (DivModState.init w)).q.getMsbD i) := by
-  simp [getMsbD_eq_getLsbD, getLsbD_udiv, udiv_eq_divRec (by assumption)]
+  simp [getMsbD_eq_getLsbD, udiv_eq_divRec (by assumption)]
 
 /- ### Arithmetic shift right (sshiftRight) recurrence -/
 
@@ -1351,7 +1304,7 @@ theorem negOverflow_eq {w : Nat} (x : BitVec w) :
     (negOverflow x) = (decide (0 < w) && (x == intMin w)) := by
   simp only [negOverflow]
   rcases w with _|w
-  · simp [toInt_of_zero_length, Int.min_eq_right]
+  · simp [toInt_of_zero_length]
   · suffices - 2 ^ w = (intMin (w + 1)).toInt by simp [beq_eq_decide_eq, ← toInt_inj, this]
     simp only [toInt_intMin, Nat.add_one_sub_one, Int.natCast_emod, Int.neg_inj]
     rw_mod_cast [Nat.mod_eq_of_lt (by simp [Nat.pow_lt_pow_succ])]
@@ -1393,7 +1346,7 @@ theorem umulOverflow_eq {w : Nat} (x y : BitVec w) :
       (0 < w && BitVec.twoPow (w * 2) w ≤ x.zeroExtend (w * 2) * y.zeroExtend (w * 2)) := by
   simp only [umulOverflow, toNat_twoPow, le_def, toNat_mul, toNat_setWidth, mod_mul_mod]
   rcases w with _|w
-  · simp [of_length_zero, toInt_zero, mul_mod_mod]
+  · simp [of_length_zero]
   · simp only [ge_iff_le, show 0 < w + 1 by omega, decide_true, mul_mod_mod, Bool.true_and,
       decide_eq_decide]
     rw [Nat.mod_eq_of_lt BitVec.toNat_mul_toNat_lt, Nat.mod_eq_of_lt]
@@ -1629,11 +1582,11 @@ theorem toInt_sdiv_of_ne_or_ne (a b : BitVec w) (h : a ≠ intMin w ∨ b ≠ -1
   have := Nat.two_pow_pos (w - 1)
 
   by_cases hbintMin : b = intMin w
-  · simp only [ne_eq, Decidable.not_not] at hbintMin
+  · simp only at hbintMin
     subst hbintMin
     have toIntA_lt := @BitVec.toInt_lt w a; norm_cast at toIntA_lt
     have le_toIntA := @BitVec.le_toInt w a; norm_cast at le_toIntA
-    simp only [sdiv_intMin, h, ↓reduceIte, toInt_zero, toInt_intMin, wpos,
+    simp only [sdiv_intMin, toInt_intMin, wpos,
       Nat.two_pow_pred_mod_two_pow, Int.tdiv_neg]
     · by_cases ha_intMin : a = intMin w
       · simp only [ha_intMin, ↓reduceIte, show 1 < w by omega, toInt_one, toInt_intMin, wpos,
@@ -1709,6 +1662,120 @@ theorem toInt_sdiv (a b : BitVec w) : (a.sdiv b).toInt = (a.toInt.tdiv b.toInt).
   · rw [← toInt_bmod_cancel]
     rw [BitVec.toInt_sdiv_of_ne_or_ne _ _ (by simpa only [Decidable.not_and_iff_not_or_not] using h)]
 
+private theorem neg_udiv_eq_intMin_iff_eq_intMin_eq_one_of_msb_eq_true
+    {x y : BitVec w} (hx : x.msb = true) (hy : y.msb = false) :
+    -x / y = intMin w ↔ (x = intMin w ∧ y = 1#w) := by
+  constructor
+  · intros h
+    rcases w with _ | w; decide +revert
+    have : (-x / y).msb = true := by simp [h, msb_intMin]
+    rw [msb_udiv] at this
+    simp only [bool_to_prop] at this
+    obtain ⟨hx, hy⟩ := this
+    simp only [beq_iff_eq] at hy
+    subst hy
+    simp only [udiv_one, neg_eq_intMin] at h
+    simp [h]
+  · rintro ⟨hx, hy⟩
+    subst hx hy
+    simp
+
+theorem getElem_sdiv {x y : BitVec w} (h : i < w) :
+    (x.sdiv y)[i] =
+      (match x.msb, y.msb with
+      | false, false => (x / y)[i]
+      | false, true => (-(x / -y))[i]
+      | true, false => (-(-x / y))[i]
+      | true, true => (-x / -y)[i]) := by
+  simp only [sdiv, udiv_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem getLsbD_sdiv {x y : BitVec w} :
+    (x.sdiv y).getLsbD i =
+      match x.msb, y.msb with
+      | false, false => (x / y).getLsbD i
+      | false, true =>( -(x / -y)).getLsbD i
+      | true, false => (-(-x / y)).getLsbD i
+      | true, true => (-x / -y).getLsbD i := by
+  simp only [sdiv, udiv_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem getMsbD_sdiv {x y : BitVec w} :
+    (x.sdiv y).getMsbD i =
+      match x.msb, y.msb with
+      | false, false => (x / y).getMsbD i
+      | false, true =>( -(x / -y)).getMsbD i
+      | true, false => (-(-x / y)).getMsbD i
+      | true, true => (-x / -y).getMsbD i := by
+  simp only [sdiv, udiv_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+/--
+the most significant bit of the signed division `x.sdiv y` can be computed
+by the following cases:
+(1) x nonneg, y nonneg: never neg.
+(2) x nonneg, y neg: neg when result nonzero.
+   We know that y is nonzero since it is negative, so we only check `|x| ≥ |y|`.
+(3) x neg, y nonneg: neg when result nonzero.
+  We check that `y ≠ 0` and `|x| ≥ |y|`.
+(4) x neg, y neg: neg when `x = intMin, `y = -1`, since `intMin / -1 = intMin`.
+
+The proof strategy is to perform a case analysis on the sign of `x` and `y`,
+followed by unfolding the `sdiv` into `udiv`.
+-/
+theorem msb_sdiv_eq_decide {x y : BitVec w} :
+    (x.sdiv y).msb = (decide (0 < w) &&
+      (!x.msb && y.msb && decide (-y ≤ x)) ||
+      (x.msb && !y.msb && decide (y ≤ -x) && !decide (y = 0#w)) ||
+      (x.msb && y.msb && decide (x = intMin w) && decide (y = -1#w)))
+     := by
+  rcases w; decide +revert
+  case succ w =>
+    simp only [sdiv_eq, udiv_eq]
+    rcases hxmsb : x.msb <;> rcases hymsb : y.msb
+    · simp [hxmsb, msb_udiv_eq_false_of, Bool.not_false, Bool.and_false, Bool.false_and,
+        Bool.and_true, Bool.or_self, Bool.and_self]
+    · simp only [hxmsb, hymsb, msb_neg, msb_udiv_eq_false_of, bne_false, Bool.not_false,
+        Bool.and_self, ne_zero_of_msb_true, decide_false, Bool.and_true, Bool.true_and, Bool.not_true,
+        Bool.false_and, Bool.or_false, bool_to_prop]
+      have : x / -y ≠ intMin (w + 1) := by
+        intros h
+        have : (x / -y).msb = (intMin (w + 1)).msb := by simp only [h]
+        simp only [msb_udiv, msb_intMin, show 0 < w + 1 by omega, decide_true, and_eq_true, beq_iff_eq] at this
+        obtain ⟨hcontra, _⟩ := this
+        simp only [hcontra, true_eq_false] at hxmsb
+      simp [this, hymsb, udiv_ne_zero_iff_ne_zero_and_le]
+    · simp only [Bool.not_true, Bool.and_self, Bool.false_and, Bool.not_false,
+        Bool.true_and, Bool.false_or, Bool.and_false, Bool.or_false]
+      by_cases hx₁ : x = 0#(w + 1)
+      · simp [hx₁, neg_zero, zero_udiv, msb_zero, le_zero_iff, Bool.and_not_self]
+      · by_cases hy₁ : y = 0#(w + 1)
+        · simp [hy₁, udiv_zero, neg_zero, msb_zero, decide_true, Bool.not_true, Bool.and_false]
+        · simp only [hy₁, decide_false, Bool.not_false, Bool.and_true]
+          by_cases hxy₁ : (- x / y) = 0#(w + 1)
+          · simp only [hxy₁, neg_zero, msb_zero, false_eq_decide_iff, BitVec.not_le,
+              BitVec.not_le]
+            simp only [udiv_eq_zero_iff_eq_zero_or_lt, hy₁, _root_.false_or] at hxy₁
+            bv_omega
+          · simp only [udiv_eq_zero_iff_eq_zero_or_lt, _root_.not_or, BitVec.not_lt,
+              hy₁, not_false_eq_true, _root_.true_and] at hxy₁
+            simp only [decide_true, msb_neg, bne_iff_ne, ne_eq,
+              bool_to_prop,
+              bne_iff_ne, ne_eq, udiv_eq_zero_iff_eq_zero_or_lt, hy₁, _root_.false_or,
+              BitVec.not_lt, hxy₁, _root_.true_and, decide_not, not_eq_eq_eq_not, not_eq_not,
+              msb_udiv, msb_neg]
+            simp only [hx₁, not_false_eq_true, _root_.true_and, decide_not, hxmsb, not_eq_eq_eq_not,
+              Bool.not_true, decide_eq_false_iff_not, Decidable.not_not, beq_iff_eq]
+            rw [neg_udiv_eq_intMin_iff_eq_intMin_eq_one_of_msb_eq_true hxmsb hymsb]
+    · simp only [msb_udiv, msb_neg, hxmsb, bne_true, Bool.not_and, Bool.not_true, Bool.and_true,
+        Bool.false_and, Bool.and_false, hymsb, ne_zero_of_msb_true, decide_false, Bool.not_false,
+        Bool.or_self, Bool.and_self, Bool.true_and, Bool.false_or]
+      simp only [bool_to_prop]
+      simp [BitVec.ne_zero_of_msb_true (x := x) hxmsb, neg_eq_iff_eq_neg]
+
 theorem msb_umod_eq_false_of_left {x : BitVec w} (hx : x.msb = false) (y : BitVec w) : (x % y).msb = false := by
   rw [msb_eq_false_iff_two_mul_lt] at hx ⊢
   rw [toNat_umod]
@@ -1724,11 +1791,44 @@ theorem msb_umod_of_le_of_ne_zero_of_le {x y : BitVec w}
   rw [← intMin_le_iff_msb_eq_true (length_pos_of_ne hy)] at h
   rwa [BitVec.le_antisymm hx h]
 
+theorem getElem_srem {x y : BitVec w} (h : i < w) :
+    (x.srem y)[i] =
+      match x.msb, y.msb with
+      | false, false => (x % y)[i]
+      | false, true => (x % -y)[i]
+      | true, false => (-(-x % y))[i]
+      | true, true => (-(-x % -y))[i] := by
+  simp only [srem, umod_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem getLsbD_srem {x y : BitVec w} :
+    (x.srem y).getLsbD i =
+      match x.msb, y.msb with
+      | false, false => (x % y).getLsbD i
+      | false, true => (x % -y).getLsbD i
+      | true, false => (-(-x % y)).getLsbD i
+      | true, true => (-(-x % -y)).getLsbD i := by
+  simp only [srem, umod_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem getMsbD_srem {x y : BitVec w} :
+    (x.srem y).getMsbD i  =
+      match x.msb, y.msb with
+      | false, false => (x % y).getMsbD i
+      | false, true => (x % -y).getMsbD i
+      | true, false => (-(-x % y)).getMsbD i
+      | true, true => (-(-x % -y)).getMsbD i := by
+  simp only [srem, umod_eq, neg_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
 @[simp]
 theorem toInt_srem (x y : BitVec w) : (x.srem y).toInt = x.toInt.tmod y.toInt := by
   rw [srem_eq]
   by_cases hyz : y = 0#w
-  · simp only [hyz, ofNat_eq_ofNat, msb_zero, umod_zero, neg_zero, neg_neg, toInt_zero, Int.tmod_zero]
+  · simp only [hyz, msb_zero, umod_zero, neg_zero, neg_neg, toInt_zero, Int.tmod_zero]
     cases x.msb <;> rfl
   cases h : x.msb
   · cases h' : y.msb
@@ -1752,6 +1852,214 @@ theorem toInt_srem (x y : BitVec w) : (x.srem y).toInt = x.toInt.tmod y.toInt :=
         ((not_congr neg_eq_zero_iff).mpr hyz)]
       exact neg_le_intMin_of_msb_eq_true h'
 
+@[simp]
+theorem msb_intMin_umod_neg_of_msb_true {y : BitVec w} (hy : y.msb = true) :
+    (intMin w % -y).msb = false := by
+  by_cases hyintmin : y = intMin w
+  · simp [hyintmin]
+  · rw [msb_umod_of_msb_false_of_ne_zero (by simp [hyintmin, hy])]
+    simp [hy]
+
+@[simp]
+theorem msb_neg_umod_neg_of_msb_true_of_msb_true {x y : BitVec w} (hx : x.msb = true) (hy : y.msb = true) :
+      (-x % -y).msb = false := by
+  by_cases hx' : x = intMin w
+  · simp only [hx', neg_intMin, msb_intMin_umod_neg_of_msb_true hy]
+  · simp [show (-x).msb = false by simp [hx, hx']]
+
+theorem toInt_dvd_toInt_iff {x y : BitVec w} :
+    y.toInt ∣ x.toInt ↔ (if x.msb then -x else x) % (if y.msb then -y else y) = 0#w := by
+  constructor
+  <;> by_cases hxmsb : x.msb <;> by_cases hymsb: y.msb
+  <;> intros h
+  <;> simp only [hxmsb, hymsb, reduceIte, false_eq_true, toNat_eq, toNat_umod, toNat_ofNat,
+        zero_mod, toInt_eq_neg_toNat_neg_of_msb_true, Int.dvd_neg, Int.neg_dvd,
+        toInt_eq_toNat_of_msb] at h
+  <;> simp only [hxmsb, hymsb, toInt_eq_neg_toNat_neg_of_msb_true, toInt_eq_toNat_of_msb,
+        Int.dvd_neg, Int.neg_dvd, toNat_eq, toNat_umod, reduceIte, toNat_ofNat, zero_mod]
+  <;> norm_cast
+  <;> norm_cast at h
+  <;> simp only [dvd_of_mod_eq_zero, h, dvd_iff_mod_eq_zero.mp, reduceIte]
+
+theorem toInt_dvd_toInt_iff_of_msb_true_msb_false {x y : BitVec w} (hx : x.msb = true) (hy : y.msb = false) :
+    y.toInt ∣ x.toInt ↔ (-x) % y = 0#w := by
+  simpa [hx, hy] using toInt_dvd_toInt_iff (x := x) (y := y)
+
+theorem toInt_dvd_toInt_iff_of_msb_false_msb_true {x y : BitVec w} (hx : x.msb = false) (hy : y.msb = true) :
+    y.toInt ∣ x.toInt ↔ x % (-y) = 0#w := by
+  simpa [hx, hy] using toInt_dvd_toInt_iff (x := x) (y := y)
+
+@[simp]
+theorem neg_toInt_neg_umod_eq_of_msb_true_msb_true {x y : BitVec w} (hx : x.msb = true) (hy : y.msb = true) :
+    -(-(-x % -y)).toInt = (-x % -y).toNat := by
+  rw [neg_toInt_neg]
+  by_cases h : -x % -y = 0#w
+  · simp [h]
+  · rw [msb_neg_umod_neg_of_msb_true_of_msb_true hx hy]
+
+@[simp]
+theorem toInt_umod_neg_add {x y : BitVec w} (hymsb : y.msb = true) (hxmsb : x.msb = false) (hdvd : ¬y.toInt ∣ x.toInt) :
+    (x % -y + y).toInt = x.toInt % y.toInt + y.toInt := by
+  rcases w with _|w ; simp [of_length_zero]
+  have hypos : 0 < y.toNat := toNat_pos_of_ne_zero (by simp [hymsb])
+  have hxnonneg := toInt_nonneg_of_msb_false hxmsb
+  have hynonpos := toInt_neg_of_msb_true hymsb
+  have hylt : (-y).toNat ≤ 2 ^ (w) := toNat_neg_lt_of_msb y hymsb
+  have hmodlt := Nat.mod_lt x.toNat (y := (-y).toNat)
+      (by rw [toNat_neg, Nat.mod_eq_of_lt (by omega)]; omega)
+  simp only [toInt_add]
+  rw [toInt_umod, toInt_eq_neg_toNat_neg_of_msb_true hymsb, Int.bmod_add_bmod,
+    Int.bmod_eq_of_le (by omega) (by omega),
+    toInt_eq_toNat_of_msb hxmsb, Int.emod_neg]
+
+@[simp]
+theorem toInt_sub_neg_umod {x y : BitVec w} (hxmsb : x.msb = true) (hymsb : y.msb = false) (hdvd : ¬y.toInt ∣ x.toInt) :
+    (y - -x % y).toInt = x.toInt % y.toInt := by
+  rcases w with _|w
+  · simp [of_length_zero]
+  · have : y.toNat < 2 ^ w := toNat_lt_of_msb_false hymsb
+    by_cases hyzero : y = 0#(w+1)
+    · subst hyzero; simp
+    · simp only [toNat_eq, toNat_ofNat, zero_mod] at hyzero
+      have hypos : 0 < y.toNat := by omega
+      simp only [toInt_sub, toInt_eq_toNat_of_msb hymsb, toInt_umod,
+        Int.sub_bmod_bmod, toInt_eq_neg_toNat_neg_of_msb_true hxmsb, Int.neg_emod]
+      have hmodlt := Nat.mod_lt (x := (-x).toNat) (y := y.toNat) hypos
+      rw [Int.bmod_eq_of_le (by omega) (by omega)]
+      simp only [toInt_eq_toNat_of_msb hymsb, BitVec.toInt_eq_neg_toNat_neg_of_msb_true hxmsb,
+        Int.dvd_neg] at hdvd
+      simp only [hdvd, ↓reduceIte, Int.natAbs_cast]
+
+theorem srem_zero_of_dvd {x y : BitVec w} (h : y.toInt ∣ x.toInt) :
+    x.srem y = 0#w := by
+  have := toInt_dvd_toInt_iff (x := x) (y := y)
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp only [h, hx, reduceIte, hy, false_eq_true, true_iff] at this
+  <;> simp [srem, hx, hy, this]
+
+/--
+The remainder for `srem`, i.e. division with rounding to zero is negative
+iff `x` is negative and `y` does not divide `x`.
+
+We can eventually build fast circuits for the divisibility test `x.srem y = 0`.
+-/ 
+theorem msb_srem {x y : BitVec w} : (x.srem y).msb =
+    (x.msb && decide (x.srem y ≠ 0)) := by
+  rw [msb_eq_toInt]
+  by_cases hx : x.msb
+  · by_cases hsrem : x.srem y = 0#w
+    · simp [hsrem]
+    · have := toInt_neg_of_msb_true hx
+      by_cases hdvd : y.toInt ∣ x.toInt
+      · simp [BitVec.srem_zero_of_dvd hdvd] at hsrem
+      · simp only [toInt_srem, Int.tmod_eq_emod, show ¬0 ≤ x.toInt by omega, hdvd, _root_.or_self,
+          reduceIte, hx, ofNat_eq_ofNat, ne_eq, hsrem, not_false_eq_true, decide_true, Bool.and_self,
+          decide_eq_true_eq, gt_iff_lt]
+        have hlt := Int.emod_lt (a := x.toInt) (b := y.toInt)
+        by_cases hy0 : y = 0#w
+        · simp only [hy0, toInt_zero, Int.emod_zero, Int.natAbs_zero, Int.cast_ofNat_Int,
+            Int.sub_zero, gt_iff_lt]
+          exact toInt_neg_of_msb_true hx
+        · simp only [← toInt_inj, toInt_zero] at hy0
+          simp only [ne_eq, hy0, not_false_eq_true, forall_const] at hlt
+          have := Int.le_natAbs (a := y.toInt)
+          omega
+  · simp only [toInt_srem, hx, ofNat_eq_ofNat, ne_eq, decide_not, Bool.false_and,
+      decide_eq_false_iff_not, Int.not_lt]
+    apply Int.tmod_nonneg y.toInt (by exact toInt_nonneg_of_msb_false (by simp at hx; exact hx))
+
+theorem toInt_smod {x y : BitVec w} :
+    (x.smod y).toInt = x.toInt.fmod y.toInt := by
+  rcases w with _|w
+  · decide +revert
+  · by_cases hyzero : y = 0#(w + 1)
+    · simp [hyzero]
+    · rw [smod_eq]
+      cases hxmsb : x.msb <;> cases hymsb : y.msb
+      <;> simp only [umod_eq]
+      · have : 0 < y.toNat := by simp [toNat_eq] at hyzero; omega
+        have : y.toNat < 2 ^ w := toNat_lt_of_msb_false hymsb
+        have : x.toNat % y.toNat < y.toNat := Nat.mod_lt x.toNat (by omega)
+        rw [toInt_umod, Int.fmod_eq_emod_of_nonneg x.toInt (toInt_nonneg_of_msb_false hymsb),
+          toInt_eq_toNat_of_msb hxmsb, toInt_eq_toNat_of_msb hymsb,
+          Int.bmod_eq_of_le_mul_two (by omega) (by omega)]
+      · have := toInt_dvd_toInt_iff_of_msb_false_msb_true hxmsb hymsb
+        by_cases hx_dvd_y : y.toInt ∣ x.toInt
+        · simp [show x % -y = 0#(w + 1) by simp_all, hx_dvd_y, Int.fmod_eq_zero_of_dvd]
+        · have hynonpos := toInt_neg_of_msb_true hymsb
+          simp only [show ¬x % -y = 0#(w + 1) by simp_all, ↓reduceIte,
+            toInt_umod_neg_add hymsb hxmsb hx_dvd_y, Int.fmod_eq_emod, show ¬0 ≤ y.toInt by omega,
+            hx_dvd_y, _root_.or_self]
+      · have hynonneg := toInt_nonneg_of_msb_false hymsb
+        rw [Int.fmod_eq_emod_of_nonneg x.toInt (b := y.toInt) (by omega)]
+        have hdvd := toInt_dvd_toInt_iff_of_msb_true_msb_false hxmsb hymsb
+        by_cases hx_dvd_y : y.toInt ∣ x.toInt
+        · simp [show -x % y = 0#(w + 1) by simp_all, hx_dvd_y, Int.emod_eq_zero_of_dvd]
+        · simp [show ¬-x % y = 0#(w + 1) by simp_all, toInt_sub_neg_umod hxmsb hymsb hx_dvd_y]
+      · rw [←Int.neg_inj, neg_toInt_neg_umod_eq_of_msb_true_msb_true hxmsb hymsb]
+        simp [BitVec.toInt_eq_neg_toNat_neg_of_msb_true, hxmsb, hymsb,
+          Int.fmod_eq_emod_of_nonneg _]
+
+theorem getElem_smod {x y : BitVec w} (h : i < w) :
+    (x.smod y)[i] =
+      match x.msb, y.msb with
+      | false, false => (x % y)[i]
+      | false, true => (if x % -y = 0#w then (x % -y) else (x % -y + y))[i]
+      | true, false => (if -x % y = 0#w then (-x % y) else (y - -x % y))[i]
+      | true, true => (-(-x % -y))[i] := by
+  simp only [smod, umod_eq, neg_eq, zero_eq, add_eq, sub_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem getLsbD_smod {x y : BitVec w} :
+    (x.smod y).getLsbD i =
+      match x.msb, y.msb with
+      | false, false => (x % y).getLsbD i
+      | false, true => if x % -y = 0#w then false else (x % -y + y).getLsbD i
+      | true, false => if -x % y = 0#w then false else (y - -x % y).getLsbD i
+      | true, true => (-(-x % -y)).getLsbD i := by
+  simp only [smod, umod_eq, neg_eq, zero_eq, add_eq, sub_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  · simp [hx, hy]
+  · by_cases hxy : -x % y = 0#w <;> simp [hx, hy, hxy]
+  · by_cases hxy : x % -y = 0#w <;> simp [hx, hy, hxy]
+  · simp [hx, hy]
+
+theorem getMsbD_smod {x y : BitVec w} :
+    (x.smod y).getMsbD i  =
+      match x.msb, y.msb with
+      | false, false => (x % y).getMsbD i
+      | false, true => (if x % -y = 0#w then (x % -y) else (x % -y + y)).getMsbD i
+      | true, false => (if -x % y = 0#w then (-x % y) else (y - -x % y)).getMsbD i
+      | true, true => (-(-x % -y)).getMsbD i := by
+  simp only [smod, umod_eq, neg_eq, zero_eq, add_eq, sub_eq]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  <;> simp [hx, hy]
+
+theorem msb_smod {x y : BitVec w} :
+    (x.smod y).msb = (x.msb && y = 0) || (y.msb && (x.smod y) ≠ 0) := by
+  rw [msb_eq_toInt]
+  by_cases hx : x.msb <;> by_cases hy : y.msb
+  · by_cases hsmod : x.smod y = 0#w <;> simp [hx, hy, hsmod]
+  · simp only [hx, ofNat_eq_ofNat, Bool.true_and, decide_eq_decide, decide_iff_dist, hy, ne_eq,
+      decide_not, Bool.false_and, Bool.or_false, beq_iff_eq]
+    constructor
+    · intro h
+      apply Classical.byContradiction
+      intro hcontra
+      rw [toInt_smod] at h
+      have := toInt_nonneg_of_msb_false (by simp at hy; exact hy)
+      have := Int.fmod_nonneg_of_pos (a := x.toInt) (b := y.toInt) (by simp [← toInt_inj] at hcontra; omega)
+      omega
+    · intro h
+      simp only [h, smod_zero]
+      exact toInt_neg_of_msb_true hx
+  · by_cases hsmod : x.smod y = 0#w <;> simp [hx, hy, hsmod]
+  · simp only [toInt_smod, hx, ofNat_eq_ofNat, Bool.false_and, decide_eq_false_iff_not, Int.not_lt,
+      hy, ne_eq, decide_not, Bool.or_false, decide_eq_true_eq]
+    simp only [not_eq_true] at hx hy
+    apply Int.fmod_nonneg (by exact toInt_nonneg_of_msb_false hx) (by exact toInt_nonneg_of_msb_false hy)
+
 /-! ### Lemmas that use bit blasting circuits -/
 
 theorem add_sub_comm {x y : BitVec w} : x + y - z = x - z + y := by
@@ -1784,7 +2092,7 @@ theorem carry_extractLsb'_eq_carry {w i len : Nat} (hi : i < len)
     {x y : BitVec w} {b : Bool}:
     (carry i (extractLsb' 0 len x) (extractLsb' 0 len y) b)
     = (carry i x y b) := by
-  simp only [carry, extractLsb'_toNat, shiftRight_zero, toNat_false, Nat.add_zero, ge_iff_le,
+  simp only [carry, extractLsb'_toNat, shiftRight_zero, ge_iff_le,
     decide_eq_decide]
   have : 2 ^ i ∣ 2^len := by
     apply Nat.pow_dvd_pow

src/Init/Data/BitVec/Bootstrap.lean

@@ -0,0 +1,157 @@
+/-
+Copyright (c) 2023 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Joe Hendrix, Harun Khan, Alex Keizer, Abdalrhman M Mohamed, Siddharth Bhat
+-/
+module
+
+prelude
+import all Init.Data.BitVec.Basic
+
+namespace BitVec
+
+theorem testBit_toNat (x : BitVec w) : x.toNat.testBit i = x.getLsbD i := rfl
+
+@[simp, grind =] theorem getLsbD_ofFin (x : Fin (2^n)) (i : Nat) :
+    getLsbD (BitVec.ofFin x) i = x.val.testBit i := rfl
+
+@[simp, grind] theorem getLsbD_of_ge (x : BitVec w) (i : Nat) (ge : w ≤ i) : getLsbD x i = false := by
+  let ⟨x, x_lt⟩ := x
+  simp only [getLsbD_ofFin]
+  apply Nat.testBit_lt_two_pow
+  have p : 2^w ≤ 2^i := Nat.pow_le_pow_right (by omega) ge
+  omega
+
+/-- Prove equality of bitvectors in terms of nat operations. -/
+theorem eq_of_toNat_eq {n} : ∀ {x y : BitVec n}, x.toNat = y.toNat → x = y
+  | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
+
+theorem eq_of_getLsbD_eq {x y : BitVec w}
+    (pred : ∀ i, i < w → x.getLsbD i = y.getLsbD i) : x = y := by
+  apply eq_of_toNat_eq
+  apply Nat.eq_of_testBit_eq
+  intro i
+  if i_lt : i < w then
+    exact pred i i_lt
+  else
+    have p : i ≥ w := Nat.le_of_not_gt i_lt
+    simp [testBit_toNat, getLsbD_of_ge _ _ p]
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_ofNat (x w : Nat) : (BitVec.ofNat w x).toNat = x % 2^w := by
+  simp [BitVec.toNat, BitVec.ofNat, Fin.ofNat]
+
+@[ext, grind ext] theorem eq_of_getElem_eq {x y : BitVec n} :
+        (∀ i (hi : i < n), x[i] = y[i]) → x = y :=
+  fun h => BitVec.eq_of_getLsbD_eq (h ↑·)
+
+@[simp, grind =] theorem toNat_append (x : BitVec m) (y : BitVec n) :
+    (x ++ y).toNat = x.toNat <<< n ||| y.toNat :=
+  rfl
+
+@[simp, grind =] theorem toNat_ofBool (b : Bool) : (ofBool b).toNat = b.toNat := by
+  cases b <;> rfl
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_cast (h : w = v) (x : BitVec w) : (x.cast h).toNat = x.toNat := rfl
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_ofFin (x : Fin (2^n)) : (BitVec.ofFin x).toNat = x.val := rfl
+
+@[simp, grind =] theorem toNat_ofNatLT (x : Nat) (p : x < 2^w) : (x#'p).toNat = x := rfl
+
+@[simp, grind =] theorem toNat_cons (b : Bool) (x : BitVec w) :
+    (cons b x).toNat = (b.toNat <<< w) ||| x.toNat := by
+  let ⟨x, _⟩ := x
+  simp only [cons, toNat_cast, toNat_append, toNat_ofBool, toNat_ofFin]
+
+@[grind =]
+theorem getElem_cons {b : Bool} {n} {x : BitVec n} {i : Nat} (h : i < n + 1) :
+    (cons b x)[i] = if h : i = n then b else x[i] := by
+  simp only [getElem_eq_testBit_toNat, toNat_cons, Nat.testBit_or]
+  rw [Nat.testBit_shiftLeft]
+  rcases Nat.lt_trichotomy i n with i_lt_n | i_eq_n | n_lt_i
+  · have p1 : ¬(n ≤ i) := by omega
+    have p2 : i ≠ n := by omega
+    simp [p1, p2]
+  · simp only [i_eq_n, ge_iff_le, Nat.le_refl, decide_true, Nat.sub_self, Nat.testBit_zero,
+    Bool.true_and, testBit_toNat, getLsbD_of_ge, Bool.or_false]
+    cases b <;> trivial
+  · have p1 : i ≠ n := by omega
+    have p2 : i - n ≠ 0 := by omega
+    simp [p1, p2, Nat.testBit_bool_toNat]
+
+private theorem lt_two_pow_of_le {x m n : Nat} (lt : x < 2 ^ m) (le : m ≤ n) : x < 2 ^ n :=
+  Nat.lt_of_lt_of_le lt (Nat.pow_le_pow_right (by trivial : 0 < 2) le)
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_setWidth' {m n : Nat} (p : m ≤ n) (x : BitVec m) :
+    (setWidth' p x).toNat = x.toNat := by
+  simp only [setWidth', toNat_ofNatLT]
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_setWidth (i : Nat) (x : BitVec n) :
+    (setWidth i x).toNat = x.toNat % 2^i := by
+  let ⟨x, lt_n⟩ := x
+  simp only [setWidth]
+  if n_le_i : n ≤ i then
+    have x_lt_two_i : x < 2 ^ i := lt_two_pow_of_le lt_n n_le_i
+    simp [n_le_i, Nat.mod_eq_of_lt, x_lt_two_i]
+  else
+    simp [n_le_i, toNat_ofNat]
+
+@[simp, grind =]
+theorem ofNat_toNat (m : Nat) (x : BitVec n) : BitVec.ofNat m x.toNat = setWidth m x := by
+  apply eq_of_toNat_eq
+  simp only [toNat_ofNat, toNat_setWidth]
+
+@[grind =]
+theorem getElem_setWidth' (x : BitVec w) (i : Nat) (h : w ≤ v) (hi : i < v) :
+    (setWidth' h x)[i] = x.getLsbD i := by
+  rw [getElem_eq_testBit_toNat, toNat_setWidth', getLsbD]
+
+@[simp, grind =]
+theorem getElem_setWidth (m : Nat) (x : BitVec n) (i : Nat) (h : i < m) :
+    (setWidth m x)[i] = x.getLsbD i := by
+  rw [setWidth]
+  split
+  · rw [getElem_setWidth']
+  · simp only [ofNat_toNat, getElem_eq_testBit_toNat, toNat_setWidth, Nat.testBit_mod_two_pow,
+      getLsbD, Bool.and_eq_right_iff_imp, decide_eq_true_eq]
+    omega
+
+-- Later this is provable by `grind`, so doesn't need an annotation.
+@[simp] theorem cons_msb_setWidth (x : BitVec (w+1)) : (cons x.msb (x.setWidth w)) = x := by
+  ext i
+  simp only [getElem_cons]
+  split <;> rename_i h
+  · simp [BitVec.msb, getMsbD, h]
+  · by_cases h' : i < w
+    · simp_all only [getElem_setWidth, getLsbD_eq_getElem]
+    · omega
+
+@[simp, bitvec_to_nat, grind =]
+theorem toNat_neg (x : BitVec n) : (- x).toNat = (2^n - x.toNat) % 2^n := by
+  simp [Neg.neg, BitVec.neg]
+
+@[simp, grind =]
+theorem setWidth_neg_of_le {x : BitVec v} (h : w ≤ v) : BitVec.setWidth w (-x) = -BitVec.setWidth w x := by
+  apply BitVec.eq_of_toNat_eq
+  simp only [toNat_setWidth, toNat_neg]
+  rw [Nat.mod_mod_of_dvd _ (Nat.pow_dvd_pow 2 h)]
+  rw [Nat.mod_eq_mod_iff]
+  rw [Nat.mod_def]
+  refine ⟨1 + x.toNat / 2^w, 2^(v-w), ?_⟩
+  rw [← Nat.pow_add]
+  have : v - w + w = v := by omega
+  rw [this]
+  rw [Nat.add_mul, Nat.one_mul, Nat.mul_comm (2^w)]
+  have sub_sub : ∀ (a : Nat) {b c : Nat} (h : c ≤ b), a - (b - c) = a + c - b := by omega
+  rw [sub_sub _ (Nat.div_mul_le_self x.toNat (2 ^ w))]
+  have : x.toNat / 2 ^ w * 2 ^ w ≤ x.toNat := Nat.div_mul_le_self x.toNat (2 ^ w)
+  have : x.toNat < 2 ^w ∨ x.toNat - 2 ^ w < x.toNat / 2 ^ w * 2 ^ w := by
+    have := Nat.lt_div_mul_add (a := x.toNat) (b := 2 ^ w) (Nat.two_pow_pos w)
+    omega
+  omega
+
+end BitVec

src/Init/Data/BitVec/Decidable.lean

@@ -0,0 +1,79 @@
+/-
+Copyright (c) 2023 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Joe Hendrix, Harun Khan, Alex Keizer, Abdalrhman M Mohamed, Siddharth Bhat
+
+-/
+module
+
+prelude
+import Init.Data.BitVec.Bootstrap
+
+set_option linter.missingDocs true
+
+namespace BitVec
+
+/-! ### Decidable quantifiers -/
+
+theorem forall_zero_iff {P : BitVec 0 → Prop} :
+    (∀ v, P v) ↔ P 0#0 := by
+  constructor
+  · intro h
+    apply h
+  · intro h v
+    obtain (rfl : v = 0#0) := (by ext i ⟨⟩)
+    apply h
+
+theorem forall_cons_iff {P : BitVec (n + 1) → Prop} :
+    (∀ v : BitVec (n + 1), P v) ↔ (∀ (x : Bool) (v : BitVec n), P (v.cons x)) := by
+  constructor
+  · intro h _ _
+    apply h
+  · intro h v
+    have w : v = (v.setWidth n).cons v.msb := by simp only [cons_msb_setWidth]
+    rw [w]
+    apply h
+
+instance instDecidableForallBitVecZero (P : BitVec 0 → Prop) :
+    ∀ [Decidable (P 0#0)], Decidable (∀ v, P v)
+  | .isTrue h => .isTrue fun v => by
+    obtain (rfl : v = 0#0) := (by ext i ⟨⟩)
+    exact h
+  | .isFalse h => .isFalse (fun w => h (w _))
+
+instance instDecidableForallBitVecSucc (P : BitVec (n+1) → Prop) [DecidablePred P]
+    [Decidable (∀ (x : Bool) (v : BitVec n), P (v.cons x))] : Decidable (∀ v, P v) :=
+  decidable_of_iff' (∀ x (v : BitVec n), P (v.cons x)) forall_cons_iff
+
+instance instDecidableExistsBitVecZero (P : BitVec 0 → Prop) [Decidable (P 0#0)] :
+    Decidable (∃ v, P v) :=
+  decidable_of_iff (¬ ∀ v, ¬ P v) Classical.not_forall_not
+
+instance instDecidableExistsBitVecSucc (P : BitVec (n+1) → Prop) [DecidablePred P]
+    [Decidable (∀ (x : Bool) (v : BitVec n), ¬ P (v.cons x))] : Decidable (∃ v, P v) :=
+  decidable_of_iff (¬ ∀ v, ¬ P v) Classical.not_forall_not
+
+/--
+For small numerals this isn't necessary (as typeclass search can use the above two instances),
+but for large numerals this provides a shortcut.
+Note, however, that for large numerals the decision procedure may be very slow,
+and you should use `bv_decide` if possible.
+-/
+instance instDecidableForallBitVec :
+    ∀ (n : Nat) (P : BitVec n → Prop) [DecidablePred P], Decidable (∀ v, P v)
+  | 0, _, _ => inferInstance
+  | n + 1, _, _ =>
+    have := instDecidableForallBitVec n
+    inferInstance
+
+/--
+For small numerals this isn't necessary (as typeclass search can use the above two instances),
+but for large numerals this provides a shortcut.
+Note, however, that for large numerals the decision procedure may be very slow.
+-/
+instance instDecidableExistsBitVec :
+    ∀ (n : Nat) (P : BitVec n → Prop) [DecidablePred P], Decidable (∃ v, P v)
+  | 0, _, _ => inferInstance
+  | _ + 1, _, _ => inferInstance
+
+end BitVec

src/Init/Data/BitVec/Folds.lean

@@ -82,9 +82,9 @@ theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
       simp only [getLsbD_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)]
+      | inl h3 => simp [(Nat.ne_of_lt h3)]
                   exact (ih hj2).1 ⟨i.val, h3⟩
-      | inr h3 => simp [h3, if_pos]
+      | inr h3 => simp [h3]
                   cases (Nat.eq_zero_or_pos j.val) with
                   | inl hj3 => congr
                                rw [← (ih hj2).2]

src/Init/Data/Bool.lean

@@ -434,9 +434,9 @@ Converts `true` to `1` and `false` to `0`.
 -/
 @[expose] def toNat (b : Bool) : Nat := cond b 1 0
 
-@[simp, bitvec_to_nat] theorem toNat_false : false.toNat = 0 := rfl
+@[simp, bitvec_to_nat, grind =] theorem toNat_false : false.toNat = 0 := rfl
 
-@[simp, bitvec_to_nat] theorem toNat_true : true.toNat = 1 := rfl
+@[simp, bitvec_to_nat, grind =] theorem toNat_true : true.toNat = 1 := rfl
 
 theorem toNat_le (c : Bool) : c.toNat ≤ 1 := by
   cases c <;> trivial
@@ -457,9 +457,9 @@ Converts `true` to `1` and `false` to `0`.
 -/
 @[expose] def toInt (b : Bool) : Int := cond b 1 0
 
-@[simp] theorem toInt_false : false.toInt = 0 := rfl
+@[simp, grind =] theorem toInt_false : false.toInt = 0 := rfl
 
-@[simp] theorem toInt_true : true.toInt = 1 := rfl
+@[simp, grind =] theorem toInt_true : true.toInt = 1 := rfl
 
 /-! ### ite -/
 
@@ -488,7 +488,7 @@ Converts `true` to `1` and `false` to `0`.
 
 @[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_eq_self]
+  cases b <;> simp
 
 /-
 `not_ite_eq_true_eq_true` and related theorems below are added for

src/Init/Data/Fin/Basic.lean

@@ -81,7 +81,7 @@ Examples:
  * `(2 : Fin 3) + (2 : Fin 3) = (1 : Fin 3)`
 -/
 protected def add : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a + b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a + b) % n, by exact mlt h⟩
 
 /--
 Multiplication modulo `n`, usually invoked via the `*` operator.
@@ -92,7 +92,7 @@ Examples:
  * `(3 : Fin 10) * (7 : Fin 10) = (1 : Fin 10)`
 -/
 protected def mul : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a * b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a * b) % n, by exact mlt h⟩
 
 /--
 Subtraction modulo `n`, usually invoked via the `-` operator.
@@ -119,7 +119,7 @@ protected def sub : Fin n → Fin n → Fin n
   using recursion on the second argument.
   See issue #4413.
   -/
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨((n - b) + a) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨((n - b) + a) % n, by exact mlt h⟩
 
 /-!
 Remark: land/lor can be defined without using (% n), but
@@ -161,19 +161,19 @@ def modn : Fin n → Nat → Fin n
 Bitwise and.
 -/
 def land : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.land a b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.land a b) % n, by exact mlt h⟩
 
 /--
 Bitwise or.
 -/
 def lor : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.lor a b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.lor a b) % n, by exact mlt h⟩
 
 /--
 Bitwise xor (“exclusive or”).
 -/
 def xor : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.xor a b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(Nat.xor a b) % n, by exact mlt h⟩
 
 /--
 Bitwise left shift of bounded numbers, with wraparound on overflow.
@@ -184,7 +184,7 @@ Examples:
  * `(1 : Fin 10) <<< (4 : Fin 10) = (6 : Fin 10)`
 -/
 def shiftLeft : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a <<< b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a <<< b) % n, by exact mlt h⟩
 
 /--
 Bitwise right shift of bounded numbers.
@@ -198,7 +198,7 @@ Examples:
  * `(15 : Fin 17) >>> (2 : Fin 17) = (3 : Fin 17)`
 -/
 def shiftRight : Fin n → Fin n → Fin n
-  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a >>> b) % n, mlt h⟩
+  | ⟨a, h⟩, ⟨b, _⟩ => ⟨(a >>> b) % n, by exact mlt h⟩
 
 instance : Add (Fin n) where
   add := Fin.add

src/Init/Data/Fin/Fold.lean

@@ -183,9 +183,7 @@ theorem foldrM_loop [Monad m] [LawfulMonad m] (f : Fin (n+1) → α → m α) (x
   | zero =>
     rw [foldrM_loop_zero, foldrM_loop_succ, pure_bind]
     conv => rhs; rw [←bind_pure (f 0 x)]
-    congr
-    funext
-    simp [foldrM_loop_zero]
+    rfl
   | succ i ih =>
     rw [foldrM_loop_succ, foldrM_loop_succ, bind_assoc]
     congr; funext; exact ih ..
@@ -254,7 +252,7 @@ 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]
+  | zero => simp [Fin.last]
   | succ n ih => rw [foldl_succ, ih (f · ·.succ), foldl_succ]; simp
 
 theorem foldl_add (f : α → Fin (n + m) → α) (x) :

src/Init/Data/Fin/Lemmas.lean

@@ -63,7 +63,7 @@ theorem mk_val (i : Fin n) : (⟨i, i.isLt⟩ : Fin n) = i := Fin.eta ..
     0 = (⟨a, ha⟩ : Fin n) ↔ a = 0 := by
   simp [eq_comm]
 
-@[simp] theorem val_ofNat (n : Nat) [NeZero n] (a : Nat) :
+@[simp, grind =] theorem val_ofNat (n : Nat) [NeZero n] (a : Nat) :
   (Fin.ofNat n a).val = a % n := rfl
 
 @[deprecated val_ofNat (since := "2025-05-28")] abbrev val_ofNat' := @val_ofNat
@@ -102,9 +102,30 @@ theorem dite_val {n : Nat} {c : Prop} [Decidable c] {x y : Fin n} :
     (if c then x else y).val = if c then x.val else y.val := by
   by_cases c <;> simp [*]
 
-instance (n : Nat) [NeZero n] : NatCast (Fin n) where
+namespace NatCast
+
+/--
+This is not a global instance, but may be activated locally via `open Fin.NatCast in ...`.
+
+This is not an instance because the `binop%` elaborator assumes that
+there are no non-trivial coercion loops,
+but this introduces a coercion from `Nat` to `Fin n` and back.
+
+Non-trivial loops lead to undesirable and counterintuitive elaboration behavior.
+For example, for `x : Fin k` and `n : Nat`,
+it causes `x < n` to be elaborated as `x < ↑n` rather than `↑x < n`,
+silently introducing wraparound arithmetic.
+
+Note: as of 2025-06-03, Mathlib has such a coercion for `Fin n` anyway!
+-/
+@[expose]
+def instNatCast (n : Nat) [NeZero n] : NatCast (Fin n) where
   natCast a := Fin.ofNat n a
 
+attribute [scoped instance] instNatCast
+
+end NatCast
+
 @[expose]
 def intCast [NeZero n] (a : Int) : Fin n :=
   if 0 ≤ a then
@@ -112,9 +133,22 @@ def intCast [NeZero n] (a : Int) : Fin n :=
   else
     - Fin.ofNat n a.natAbs
 
-instance (n : Nat) [NeZero n] : IntCast (Fin n) where
+namespace IntCast
+
+/--
+This is not a global instance, but may be activated locally via `open Fin.IntCast in ...`.
+
+See the doc-string for `Fin.NatCast.instNatCast` for more details.
+-/
+@[expose]
+def instIntCast (n : Nat) [NeZero n] : IntCast (Fin n) where
   intCast := Fin.intCast
 
+attribute [scoped instance] instIntCast
+
+end IntCast
+
+open IntCast in
 theorem intCast_def {n : Nat} [NeZero n] (x : Int) :
     (x : Fin n) = if 0 ≤ x then Fin.ofNat n x.natAbs else -Fin.ofNat n x.natAbs := rfl
 
@@ -215,7 +249,7 @@ protected theorem le_antisymm_iff {x y : Fin n} : x = y ↔ x ≤ y ∧ y ≤ x
 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, grind =] 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
   rw [val_rev, val_rev, ← Nat.sub_sub, Nat.sub_sub_self (by exact i.2), Nat.add_sub_cancel]
@@ -347,7 +381,7 @@ theorem zero_ne_one : (0 : Fin (n + 2)) ≠ 1 := Fin.ne_of_lt one_pos
 @[simp] theorem val_succ (j : Fin n) : (j.succ : Nat) = j + 1 := rfl
 
 @[simp] theorem succ_pos (a : Fin n) : (0 : Fin (n + 1)) < a.succ := by
-  simp [Fin.lt_def, Nat.succ_pos]
+  simp [Fin.lt_def]
 
 @[simp] theorem succ_le_succ_iff {a b : Fin n} : a.succ ≤ b.succ ↔ a ≤ b := Nat.succ_le_succ_iff
 
@@ -380,7 +414,7 @@ theorem one_lt_succ_succ (a : Fin n) : (1 : Fin (n + 2)) < a.succ.succ := by
   simp only [lt_def, val_add, val_last, Fin.ext_iff]
   let ⟨k, hk⟩ := k
   match Nat.eq_or_lt_of_le (Nat.le_of_lt_succ hk) with
-  | .inl h => cases h; simp [Nat.succ_pos]
+  | .inl h => cases h; simp
   | .inr hk' => simp [Nat.ne_of_lt hk', Nat.mod_eq_of_lt (Nat.succ_lt_succ hk'), Nat.le_succ]
 
 @[simp] theorem add_one_le_iff {n : Nat} : ∀ {k : Fin (n + 1)}, k + 1 ≤ k ↔ k = last _ := by
@@ -392,7 +426,7 @@ theorem one_lt_succ_succ (a : Fin n) : (1 : Fin (n + 2)) < a.succ.succ := by
     intro (k : Fin (n+2))
     rw [← add_one_lt_iff, lt_def, le_def, Nat.lt_iff_le_and_ne, and_iff_left]
     rw [val_add_one]
-    split <;> simp [*, (Nat.succ_ne_zero _).symm, Nat.ne_of_gt (Nat.lt_succ_self _)]
+    split <;> simp [*, Nat.ne_of_gt (Nat.lt_succ_self _)]
 
 @[simp] theorem last_le_iff {n : Nat} {k : Fin (n + 1)} : last n ≤ k ↔ k = last n := by
   rw [Fin.ext_iff, Nat.le_antisymm_iff, le_def, and_iff_right (by apply le_last)]
@@ -411,7 +445,7 @@ theorem succ_succ_ne_one (a : Fin n) : Fin.succ (Fin.succ a) ≠ 1 :=
 @[simp] theorem castLT_mk (i n m : Nat) (hn : i < n) (hm : i < m) : castLT ⟨i, hn⟩ hm = ⟨i, hm⟩ :=
   rfl
 
-@[simp] theorem coe_castLE (h : n ≤ m) (i : Fin n) : (castLE h i : Nat) = i := rfl
+@[simp, grind =] theorem coe_castLE (h : n ≤ m) (i : Fin n) : (castLE h i : Nat) = i := rfl
 
 @[simp] theorem castLE_mk (i n m : Nat) (hn : i < n) (h : n ≤ m) :
     castLE h ⟨i, hn⟩ = ⟨i, Nat.lt_of_lt_of_le hn h⟩ := rfl
@@ -704,7 +738,7 @@ theorem pred_mk {n : Nat} (i : Nat) (h : i < n + 1) (w) : Fin.pred ⟨i, h⟩ w
     ∀ {a b : Fin (n + 1)} {ha : a ≠ 0} {hb : b ≠ 0}, a.pred ha = b.pred hb ↔ a = b
   | ⟨0, _⟩, _, ha, _ => by simp only [mk_zero, ne_eq, not_true] at ha
   | ⟨i + 1, _⟩, ⟨0, _⟩, _, hb => by simp only [mk_zero, ne_eq, not_true] at hb
-  | ⟨i + 1, hi⟩, ⟨j + 1, hj⟩, ha, hb => by simp [Fin.ext_iff, Nat.succ.injEq]
+  | ⟨i + 1, hi⟩, ⟨j + 1, hj⟩, ha, hb => by simp [Fin.ext_iff]
 
 @[simp] theorem pred_one {n : Nat} :
     Fin.pred (1 : Fin (n + 2)) (Ne.symm (Fin.ne_of_lt one_pos)) = 0 := rfl
@@ -1045,6 +1079,17 @@ theorem val_neg {n : Nat} [NeZero n] (x : Fin n) :
     have := Fin.val_ne_zero_iff.mpr h
     omega
 
+protected theorem sub_eq_add_neg {n : Nat} (x y : Fin n) : x - y = x + -y := by
+  by_cases h : n = 0
+  · subst h
+    apply elim0 x
+  · replace h : NeZero n := ⟨h⟩
+    ext
+    rw [Fin.coe_sub, Fin.val_add, val_neg]
+    split
+    · simp_all
+    · simp [Nat.add_comm]
+
 /-! ### mul -/
 
 theorem ofNat_mul [NeZero n] (x : Nat) (y : Fin n) :
@@ -1072,7 +1117,7 @@ protected theorem mul_one [i : NeZero n] (k : Fin n) : k * 1 = k := by
   | n + 1, _ =>
     match n with
     | 0 => exact Subsingleton.elim (α := Fin 1) ..
-    | n+1 => simp [Fin.ext_iff, mul_def, Nat.mod_eq_of_lt (is_lt k)]
+    | n+1 => simp [mul_def, Nat.mod_eq_of_lt (is_lt k)]
 
 protected theorem mul_comm (a b : Fin n) : a * b = b * a :=
   Fin.ext <| by rw [mul_def, mul_def, Nat.mul_comm]

src/Init/Data/Format/Basic.lean

@@ -12,8 +12,9 @@ import Init.Data.String.Basic
 
 namespace Std
 
-/-- Determines how groups should have linebreaks inserted when the
-text would overfill its remaining space.
+/--
+Determines how groups should have linebreaks inserted when the text would overfill its remaining
+space.
 
 - `allOrNone` will make a linebreak on every `Format.line` in the group or none of them.
   ```
@@ -28,60 +29,83 @@ text would overfill its remaining space.
   ```
 -/
 inductive Format.FlattenBehavior where
+  /--
+  Either all `Format.line`s in the group will be newlines, or all of them will be spaces.
+  -/
   | allOrNone
+  /--
+  As few `Format.line`s in the group as possible will be newlines.
+  -/
   | fill
   deriving Inhabited, BEq
 
 open Format in
-/-- A string with pretty-printing information for rendering in a column-width-aware way.
+/--
+A representation of a set of strings, in which the placement of newlines and indentation differ.
+
+Given a specific line width, specified in columns, the string that uses the fewest lines can be
+selected.
 
 The pretty-printing algorithm is based on Wadler's paper
-[_A Prettier Printer_](https://homepages.inf.ed.ac.uk/wadler/papers/prettier/prettier.pdf). -/
+[_A Prettier Printer_](https://homepages.inf.ed.ac.uk/wadler/papers/prettier/prettier.pdf).
+-/
 inductive Format where
   /-- The empty format. -/
   | nil                 : Format
-  /-- A position where a newline may be inserted
-  if the current group does not fit within the allotted column width. -/
+  /--
+  A position where a newline may be inserted if the current group does not fit within the allotted
+  column width.
+  -/
   | line                : Format
-  /-- `align` tells the formatter to pad with spaces to the current indent,
-  or else add a newline if we are already at or past the indent. For example:
-  ```
-  nest 2 <| "." ++ align ++ "a" ++ line ++ "b"
-  ```
-  results in:
+  /--
+  `align` tells the formatter to pad with spaces to the current indentation level, or else add a
+  newline if we are already at or past the indent.
+
+  If `force` is true, then it will pad to the indent even if it is in a flattened group.
+
+  Example:
+  ```lean example
+  open Std Format in
+  #eval IO.println (nest 2 <| "." ++ align ++ "a" ++ line ++ "b")
   ```
+  ```lean output
   . a
     b
   ```
-  If `force` is true, then it will pad to the indent even if it is in a flattened group.
   -/
   | align (force : Bool) : Format
-  /-- A node containing a plain string. -/
-  | text                : String → Format
-  /-- `nest n f` tells the formatter that `f` is nested inside something with length `n`
-  so that it is pretty-printed with the correct indentation on a line break.
-  For example, we can define a formatter for list `l : List Format` as:
+  /--
+  A node containing a plain string.
 
-  ```
-  let f := join <| l.intersperse <| ", " ++ Format.line
-  group (nest 1 <| "[" ++ f ++ "]")
-  ```
-
-  This will be written all on one line, but if the text is too large,
-  the formatter will put in linebreaks after the commas and indent later lines by 1.
+  If the string contains newlines, the formatter emits them and then indents to the current level.
   -/
-  | nest (indent : Int) : Format → Format
-  /-- Concatenation of two Formats. -/
-  | append              : Format → Format → Format
-  /-- Creates a new flattening group for the given inner format.  -/
-  | group               : Format → (behavior : FlattenBehavior := FlattenBehavior.allOrNone) → Format
+  | text                : String → Format
+  /--
+  `nest indent f` increases the current indentation level by `indent` while rendering `f`.
+
+  Example:
+  ```lean example
+  open Std Format in
+  def fmtList (l : List Format) : Format :=
+    let f := joinSep l  (", " ++ Format.line)
+    group (nest 1 <| "[" ++ f ++ "]")
+  ```
+
+  This will be written all on one line, but if the text is too large, the formatter will put in
+  linebreaks after the commas and indent later lines by 1.
+  -/
+  | nest (indent : Int) (f : Format) : Format
+  /-- Concatenation of two `Format`s. -/
+  | append : Format → Format → Format
+  /-- Creates a new flattening group for the given inner `Format`.  -/
+  | group : Format → (behavior : FlattenBehavior := FlattenBehavior.allOrNone) → Format
   /-- Used for associating auxiliary information (e.g. `Expr`s) with `Format` objects. -/
-  | tag                 : Nat → Format → Format
+  | tag : Nat → Format → Format
   deriving Inhabited
 
 namespace Format
 
-/-- Check whether the given format contains no characters. -/
+/-- Checks whether the given format contains no characters. -/
 def isEmpty : Format → Bool
   | nil          => true
   | line         => false
@@ -92,16 +116,29 @@ def isEmpty : Format → Bool
   | group f _    => f.isEmpty
   | tag _ f      => f.isEmpty
 
-/-- Alias for a group with `FlattenBehavior` set to `fill`. -/
+/--
+Creates a group in which as few `Format.line`s as possible are rendered as newlines.
+
+This is an alias for `Format.group`, with `FlattenBehavior` set to `fill`.
+-/
 def fill (f : Format) : Format :=
   group f (behavior := FlattenBehavior.fill)
 
 instance : Append Format     := ⟨Format.append⟩
 instance : Coe String Format := ⟨text⟩
 
+/--
+Concatenates a list of `Format`s with `++`.
+-/
 def join (xs : List Format) : Format :=
   xs.foldl (·++·) ""
 
+/--
+Checks whether a `Format` is the constructor `Format.nil`.
+
+This does not check whether the resulting rendered strings are always empty. To do that, use
+`Format.isEmpty`.
+-/
 def isNil : Format → Bool
   | nil => true
   | _   => false
@@ -174,15 +211,30 @@ private partial def spaceUptoLine' : List WorkGroup → Nat → Nat → SpaceRes
       (spaceUptoLine i.f g.fla.shouldFlatten (w + col - i.indent) w)
       (spaceUptoLine' ({ g with items := is }::gs) col)
 
-/-- A monad in which we can pretty-print `Format` objects. -/
+/--
+A monad that can be used to incrementally render `Format` objects.
+-/
 class MonadPrettyFormat (m : Type → Type) where
-  pushOutput (s : String)    : m Unit
+  /--
+  Emits the string `s`.
+  -/
+  pushOutput (s : String) : m Unit
+  /--
+  Emits a newline followed by `indent` columns of indentation.
+  -/
   pushNewline (indent : Nat) : m Unit
-  currColumn                 : m Nat
-  /-- Start a scope tagged with `n`. -/
-  startTag                   : Nat → m Unit
-  /-- Exit the scope of `n`-many opened tags. -/
-  endTags                    : Nat → m Unit
+  /--
+  Gets the current column at which the next string will be emitted.
+  -/
+  currColumn : m Nat
+  /--
+  Starts a region tagged with `tag`.
+  -/
+  startTag (tag : Nat) : m Unit
+  /--
+  Exits the scope of `count` opened tags.
+  -/
+  endTags (count : Nat) : m Unit
 open MonadPrettyFormat
 
 private def pushGroup (flb : FlattenBehavior) (items : List WorkItem) (gs : List WorkGroup) (w : Nat) [Monad m] [MonadPrettyFormat m] : m (List WorkGroup) := do
@@ -276,35 +328,59 @@ private partial def be (w : Nat) [Monad m] [MonadPrettyFormat m] : List WorkGrou
       else
         pushGroup flb [{ i with f }] (gs' is) w >>= be w
 
-/-- Render the given `f : Format` with a line width of `w`.
+/- Render the given `f : Format` with a line width of `w`.
 `indent` is the starting amount to indent each line by. -/
+/--
+Renders a `Format` using effects in the monad `m`, using the methods of `MonadPrettyFormat`.
+
+Each line is emitted as soon as it is rendered, rather than waiting for the entire document to be
+rendered.
+* `w`: the total width
+* `indent`: the initial indentation to use for wrapped lines (subsequent wrapping may increase the
+  indentation)
+-/
 def prettyM (f : Format) (w : Nat) (indent : Nat := 0) [Monad m] [MonadPrettyFormat m] : m Unit :=
   be w [{ flb := FlattenBehavior.allOrNone, fla := .disallow, items := [{ f := f, indent, activeTags := 0 }]}]
 
-/-- Create a format `l ++ f ++ r` with a flatten group.
-FlattenBehaviour is `allOrNone`; for `fill` use `bracketFill`. -/
+/--
+Creates a format `l ++ f ++ r` with a flattening group, nesting the contents by the length of `l`.
+
+The group's `FlattenBehavior` is `allOrNone`; for `fill` use `Std.Format.bracketFill`.
+-/
 @[inline] def bracket (l : String) (f : Format) (r : String) : Format :=
   group (nest l.length $ l ++ f ++ r)
 
-/-- Creates the format `"(" ++ f ++ ")"` with a flattening group.-/
+/--
+Creates the format `"(" ++ f ++ ")"` with a flattening group, nesting by one space.
+-/
 @[inline] def paren (f : Format) : Format :=
   bracket "(" f ")"
 
-/-- Creates the format `"[" ++ f ++ "]"` with a flattening group.-/
+/--
+Creates the format `"[" ++ f ++ "]"` with a flattening group, nesting by one space.
+
+`sbracket` is short for “square bracket”.
+-/
 @[inline] def sbracket (f : Format) : Format :=
   bracket "[" f "]"
 
-/-- Same as `bracket` except uses the `fill` flattening behaviour. -/
+/--
+Creates a format `l ++ f ++ r` with a flattening group, nesting the contents by the length of `l`.
+
+The group's `FlattenBehavior` is `fill`; for `allOrNone` use `Std.Format.bracketFill`.
+-/
 @[inline] def bracketFill (l : String) (f : Format) (r : String) : Format :=
   fill (nest l.length $ l ++ f ++ r)
 
-/-- Default indentation. -/
+/-- The default indentation level, which is two spaces. -/
 def defIndent  := 2
 def defUnicode := true
-/-- Default width of the targeted output pane. -/
+/-- The default width of the targeted output, which is 120 columns. -/
 def defWidth   := 120
 
-/-- Nest with the default indentation amount.-/
+/--
+Increases the indentation level by the default amount.
+-/
 def nestD (f : Format) : Format :=
   nest defIndent f
 
@@ -317,7 +393,7 @@ private structure State where
   out    : String := ""
   column : Nat    := 0
 
-instance : MonadPrettyFormat (StateM State) where
+private instance : MonadPrettyFormat (StateM State) where
   -- We avoid a structure instance update, and write these functions using pattern matching because of issue #316
   pushOutput s       := modify fun ⟨out, col⟩ => ⟨out ++ s, col + s.length⟩
   pushNewline indent := modify fun ⟨out, _⟩ => ⟨out ++ "\n".pushn ' ' indent, indent⟩
@@ -340,8 +416,12 @@ def pretty (f : Format) (width : Nat := defWidth) (indent : Nat := 0) (column :=
 
 end Format
 
-/-- Class for converting a given type α to a `Format` object for pretty-printing.
-See also `Repr`, which also outputs a `Format` object. -/
+/--
+Specifies a “user-facing” way to convert from the type `α` to a `Format` object. There is no
+expectation that the resulting string is valid code.
+
+The `Repr` class is similar, but the expectation is that instances produce valid Lean code.
+-/
 class ToFormat (α : Type u) where
   format : α → Format
 
@@ -354,18 +434,31 @@ instance : ToFormat Format where
 instance : ToFormat String where
   format s := Format.text s
 
-/-- Intersperse the given list (each item printed with `format`) with the given `sep` format. -/
+/--
+Intercalates the given list with the given `sep` format.
+
+The list items are formatting using `ToFormat.format`.
+-/
 def Format.joinSep {α : Type u} [ToFormat α] : List α → Format → Format
   | [],    _   => nil
   | [a],   _   => format a
   | a::as, sep => as.foldl (· ++ sep ++ format ·) (format a)
 
-/-- Format each item in `items` and prepend prefix `pre`. -/
+/--
+Concatenates the given list after prepending `pre` to each element.
+
+The list items are formatting using `ToFormat.format`.
+-/
 def Format.prefixJoin {α : Type u} [ToFormat α] (pre : Format) : List α → Format
   | []    => nil
   | a::as => as.foldl (· ++ pre ++ format ·) (pre ++ format a)
 
-/-- Format each item in `items` and append `suffix`. -/
+/--
+Concatenates the given list after appending the given suffix to each element.
+
+The list items are formatting using `ToFormat.format`.
+-/
+
 def Format.joinSuffix {α : Type u} [ToFormat α] : List α → Format → Format
   | [],    _      => nil
   | a::as, suffix => as.foldl (· ++ format · ++ suffix) (format a ++ suffix)

src/Init/Data/Function.lean

@@ -31,19 +31,19 @@ Examples:
 @[inline, expose]
 def uncurry : (α → β → φ) → α × β → φ := fun f a => f a.1 a.2
 
-@[simp]
+@[simp, grind]
 theorem curry_uncurry (f : α → β → φ) : curry (uncurry f) = f :=
   rfl
 
-@[simp]
+@[simp, grind]
 theorem uncurry_curry (f : α × β → φ) : uncurry (curry f) = f :=
   funext fun ⟨_a, _b⟩ => rfl
 
-@[simp]
+@[simp, grind]
 theorem uncurry_apply_pair {α β γ} (f : α → β → γ) (x : α) (y : β) : uncurry f (x, y) = f x y :=
   rfl
 
-@[simp]
+@[simp, grind]
 theorem curry_apply {α β γ} (f : α × β → γ) (x : α) (y : β) : curry f x y = f (x, y) :=
   rfl
 

src/Init/Data/Int/Basic.lean

@@ -269,7 +269,7 @@ set_option bootstrap.genMatcherCode false in
 
   Implemented by efficient native code. -/
 @[extern "lean_int_dec_nonneg"]
-private def decNonneg (m : @& Int) : Decidable (NonNeg m) :=
+def decNonneg (m : @& Int) : Decidable (NonNeg m) :=
   match m with
   | ofNat m => isTrue <| NonNeg.mk m
   | -[_ +1] => isFalse <| fun h => nomatch h

src/Init/Data/Int/Bitwise/Lemmas.lean

@@ -21,6 +21,7 @@ theorem natCast_shiftRight (n s : Nat) : (n : Int) >>> s = n >>> s := rfl
 theorem negSucc_shiftRight (m n : Nat) :
     -[m+1] >>> n = -[m >>>n +1] := rfl
 
+@[grind _=_]
 theorem shiftRight_add (i : Int) (m n : Nat) :
     i >>> (m + n) = i >>> m >>> n := by
   simp only [shiftRight_eq, Int.shiftRight]

src/Init/Data/Int/Compare.lean

@@ -37,7 +37,7 @@ theorem compare_eq_ite_le (a b : Int) :
   · next hlt => simp [Int.le_of_lt hlt, Int.not_le.2 hlt]
   · next hge =>
     split
-    · next hgt => simp [Int.le_of_lt hgt, Int.not_le.2 hgt]
+    · next hgt => simp [Int.not_le.2 hgt]
     · next hle => simp [Int.not_lt.1 hge, Int.not_lt.1 hle]
 
 protected theorem compare_swap (a b : Int) : (compare a b).swap = compare b a := by

src/Init/Data/Int/DivMod/Bootstrap.lean

@@ -3,7 +3,6 @@ Copyright (c) 2016 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Mario Carneiro
 -/
-
 module
 
 prelude
@@ -57,7 +56,7 @@ protected theorem dvd_trans : ∀ {a b c : Int}, a ∣ b → b ∣ c → a ∣ c
 
 @[simp] protected theorem dvd_neg {a b : Int} : a ∣ -b ↔ a ∣ b := by
   constructor <;> exact fun ⟨k, e⟩ =>
-    ⟨-k, by simp [← e, Int.neg_mul, Int.mul_neg, Int.neg_neg]⟩
+    ⟨-k, by simp [← e, Int.mul_neg, Int.neg_neg]⟩
 
 @[simp] theorem natAbs_dvd_natAbs {a b : Int} : natAbs a ∣ natAbs b ↔ a ∣ b := by
   refine ⟨fun ⟨k, hk⟩ => ?_, fun ⟨k, hk⟩ => ⟨natAbs k, hk.symm ▸ natAbs_mul a k⟩⟩
@@ -99,7 +98,7 @@ theorem ofNat_emod (m n : Nat) : (↑(m % n) : Int) = m % n := natCast_emod m n
 theorem emod_add_ediv : ∀ a b : Int, a % b + b * (a / b) = a
   | ofNat _, ofNat _ => congrArg ofNat <| Nat.mod_add_div ..
   | ofNat m, -[n+1] => by
-    show (m % succ n + -↑(succ n) * -↑(m / succ n) : Int) = m
+    change (m % succ n + -↑(succ n) * -↑(m / succ n) : Int) = m
     rw [Int.neg_mul_neg]; exact congrArg ofNat <| Nat.mod_add_div ..
   | -[_+1], 0 => by rw [emod_zero]; rfl
   | -[m+1], succ n => aux m n.succ
@@ -149,7 +148,7 @@ theorem add_mul_ediv_right (a b : Int) {c : Int} (H : c ≠ 0) : (a + b * c) / c
   fun {k n} => @fun
   | ofNat _ => congrArg ofNat <| Nat.add_mul_div_right _ _ k.succ_pos
   | -[m+1] => by
-    show ((n * k.succ : Nat) - m.succ : Int).ediv k.succ = n - (m / k.succ + 1 : Nat)
+    change ((n * k.succ : Nat) - m.succ : Int).ediv k.succ = n - (m / k.succ + 1 : Nat)
     by_cases h : m < n * k.succ
     · rw [← Int.ofNat_sub h, ← Int.ofNat_sub ((Nat.div_lt_iff_lt_mul k.succ_pos).2 h)]
       apply congrArg ofNat
@@ -158,7 +157,7 @@ theorem add_mul_ediv_right (a b : Int) {c : Int} (H : c ≠ 0) : (a + b * c) / c
       have H {a b : Nat} (h : a ≤ b) : (a : Int) + -((b : Int) + 1) = -[b - a +1] := by
         rw [negSucc_eq, Int.ofNat_sub h]
         simp only [Int.sub_eq_add_neg, Int.neg_add, Int.neg_neg, Int.add_left_comm, Int.add_assoc]
-      show ediv (↑(n * succ k) + -((m : Int) + 1)) (succ k) = n + -(↑(m / succ k) + 1 : Int)
+      change ediv (↑(n * succ k) + -((m : Int) + 1)) (succ k) = n + -(↑(m / succ k) + 1 : Int)
       rw [H h, H ((Nat.le_div_iff_mul_le k.succ_pos).2 h)]
       apply congrArg negSucc
       rw [Nat.mul_comm, Nat.sub_mul_div_of_le]; rwa [Nat.mul_comm]

src/Init/Data/Int/DivMod/Lemmas.lean

@@ -3,7 +3,6 @@ Copyright (c) 2016 Jeremy Avigad. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jeremy Avigad, Mario Carneiro, Kim Morrison, Markus Himmel
 -/
-
 module
 
 prelude
@@ -203,6 +202,9 @@ theorem tdiv_eq_ediv_of_nonneg : ∀ {a b : Int}, 0 ≤ a → a.tdiv b = a / b
   | succ _, succ _, _ => rfl
   | succ _, -[_+1], _ => rfl
 
+@[simp] theorem natCast_tdiv_eq_ediv {a : Nat} {b : Int} : (a : Int).tdiv b = a / b :=
+    tdiv_eq_ediv_of_nonneg (by simp)
+
 theorem tdiv_eq_ediv {a b : Int} :
     a.tdiv b = a / b + if 0 ≤ a ∨ b ∣ a then 0 else sign b := by
   simp only [dvd_iff_emod_eq_zero]
@@ -215,7 +217,7 @@ theorem tdiv_eq_ediv {a b : Int} :
       negSucc_not_nonneg, sign_of_add_one]
     simp only [negSucc_emod_ofNat_succ_eq_zero_iff]
     norm_cast
-    simp only [subNat_eq_zero_iff, Nat.succ_eq_add_one, sign_negSucc, Int.sub_neg, false_or]
+    simp only [Nat.succ_eq_add_one, false_or]
     split <;> rename_i h
     · rw [Int.add_zero, neg_ofNat_eq_negSucc_iff]
       exact Nat.succ_div_of_mod_eq_zero h
@@ -329,17 +331,17 @@ theorem fdiv_eq_ediv_of_dvd {a b : Int} (h : b ∣ a) : a.fdiv b = a / b := by
 theorem tmod_add_tdiv : ∀ a b : Int, tmod a b + b * (a.tdiv b) = a
   | ofNat _, ofNat _ => congrArg ofNat (Nat.mod_add_div ..)
   | ofNat m, -[n+1] => by
-    show (m % succ n + -↑(succ n) * -↑(m / succ n) : Int) = m
+    change (m % succ n + -↑(succ n) * -↑(m / succ n) : Int) = m
     rw [Int.neg_mul_neg]; exact congrArg ofNat (Nat.mod_add_div ..)
   | -[m+1], 0 => by
-    show -(↑((succ m) % 0) : Int) + 0 * -↑(succ m / 0) = -↑(succ m)
+    change -(↑((succ m) % 0) : Int) + 0 * -↑(succ m / 0) = -↑(succ m)
     rw [Nat.mod_zero, Int.zero_mul, Int.add_zero]
   | -[m+1], ofNat n => by
-    show -(↑((succ m) % n) : Int) + ↑n * -↑(succ m / n) = -↑(succ m)
+    change -(↑((succ m) % n) : Int) + ↑n * -↑(succ m / n) = -↑(succ m)
     rw [Int.mul_neg, ← Int.neg_add]
     exact congrArg (-ofNat ·) (Nat.mod_add_div ..)
   | -[m+1], -[n+1] => by
-    show -(↑(succ m % succ n) : Int) + -↑(succ n) * ↑(succ m / succ n) = -↑(succ m)
+    change -(↑(succ m % succ n) : Int) + -↑(succ n) * ↑(succ m / succ n) = -↑(succ m)
     rw [Int.neg_mul, ← Int.neg_add]
     exact congrArg (-ofNat ·) (Nat.mod_add_div ..)
 
@@ -361,17 +363,17 @@ theorem fmod_add_fdiv : ∀ a b : Int, a.fmod b + b * a.fdiv b = a
   | 0, ofNat _ | 0, -[_+1] => congrArg ofNat <| by simp
   | succ _, ofNat _ => congrArg ofNat <| Nat.mod_add_div ..
   | succ m, -[n+1] => by
-    show subNatNat (m % succ n) n + (↑(succ n * (m / succ n)) + n + 1) = (m + 1)
+    change subNatNat (m % succ n) n + (↑(succ n * (m / succ n)) + n + 1) = (m + 1)
     rw [Int.add_comm _ n, ← Int.add_assoc, ← Int.add_assoc,
       Int.subNatNat_eq_coe, Int.sub_add_cancel]
     exact congrArg (ofNat · + 1) <| Nat.mod_add_div ..
   | -[_+1], 0 => by rw [fmod_zero]; rfl
   | -[m+1], succ n => by
-    show subNatNat .. - (↑(succ n * (m / succ n)) + ↑(succ n)) = -↑(succ m)
+    change subNatNat .. - (↑(succ n * (m / succ n)) + ↑(succ n)) = -↑(succ m)
     rw [Int.subNatNat_eq_coe, ← Int.sub_sub, ← Int.neg_sub, Int.sub_sub, Int.sub_sub_self]
     exact congrArg (-ofNat ·) <| Nat.succ_add .. ▸ Nat.mod_add_div .. ▸ rfl
   | -[m+1], -[n+1] => by
-    show -(↑(succ m % succ n) : Int) + -↑(succ n * (succ m / succ n)) = -↑(succ m)
+    change -(↑(succ m % succ n) : Int) + -↑(succ n * (succ m / succ n)) = -↑(succ m)
     rw [← Int.neg_add]; exact congrArg (-ofNat ·) <| Nat.mod_add_div ..
 
 /-- Variant of `fmod_add_fdiv` with the multiplication written the other way around. -/
@@ -572,7 +574,7 @@ theorem neg_one_ediv (b : Int) : -1 / b = -b.sign :=
       · refine Nat.le_trans ?_ (Nat.le_add_right _ _)
         rw [← Nat.mul_div_mul_left _ _ m.succ_pos]
         apply Nat.div_mul_le_self
-      · show m.succ * n.succ ≤ _
+      · change m.succ * n.succ ≤ _
         rw [Nat.mul_left_comm]
         apply Nat.mul_le_mul_left
         apply (Nat.div_lt_iff_lt_mul k.succ_pos).1
@@ -1315,7 +1317,7 @@ protected theorem eq_tdiv_of_mul_eq_left {a b c : Int}
   | 0, n => by simp [Int.neg_zero]
   | succ _, (n:Nat) => by simp [tdiv, ← Int.negSucc_eq]
   | -[_+1], 0 | -[_+1], -[_+1] => by
-    simp only [tdiv, neg_negSucc, ← Int.natCast_succ, Int.neg_neg]
+    simp only [tdiv, neg_negSucc, Int.neg_neg]
   | succ _, -[_+1] | -[_+1], succ _ => (Int.neg_neg _).symm
 
 protected theorem neg_tdiv_neg (a b : Int) : (-a).tdiv (-b) = a.tdiv b := by
@@ -1406,7 +1408,7 @@ theorem mul_tmod (a b n : Int) : (a * b).tmod n = (a.tmod n * b.tmod n).tmod n :
   case inv => simp [Int.dvd_neg]
   induction m using wlog_sign
   case inv => simp
-  simp only [← Int.natCast_mul, ← ofNat_tmod]
+  simp only [← ofNat_tmod]
   norm_cast at h
   rw [Nat.mod_mod_of_dvd _ h]
 
@@ -1574,7 +1576,7 @@ theorem neg_mul_tmod_left (a b : Int) : (-(a * b)).tmod b = 0 := by
 
 @[simp] protected theorem tdiv_one : ∀ a : Int, a.tdiv 1 = a
   | (n:Nat) => congrArg ofNat (Nat.div_one _)
-  | -[n+1] => by simp [Int.tdiv, neg_ofNat_succ]; rfl
+  | -[n+1] => by simp [Int.tdiv]; rfl
 
 @[simp] theorem tmod_one (a : Int) : tmod a 1 = 0 := by
   simp [tmod_def, Int.tdiv_one, Int.one_mul, Int.sub_self]
@@ -1696,7 +1698,7 @@ theorem lt_ediv_iff_of_dvd_of_neg {a b c : Int} (hc : c < 0) (hcb : c ∣ b) :
 theorem ediv_le_ediv_iff_of_dvd_of_pos_of_pos {a b c d : Int} (hb : 0 < b) (hd : 0 < d)
     (hba : b ∣ a) (hdc : d ∣ c) : a / b ≤ c / d ↔ d * a ≤ c * b := by
   obtain ⟨⟨x, rfl⟩, y, rfl⟩ := hba, hdc
-  simp [*, Int.ne_of_lt, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
+  simp [*, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
 
 theorem ediv_le_ediv_iff_of_dvd_of_pos_of_neg {a b c d : Int} (hb : 0 < b) (hd : d < 0)
     (hba : b ∣ a) (hdc : d ∣ c) : a / b ≤ c / d ↔ c * b ≤ d * a := by
@@ -1711,12 +1713,12 @@ theorem ediv_le_ediv_iff_of_dvd_of_neg_of_pos {a b c d : Int} (hb : b < 0) (hd :
 theorem ediv_le_ediv_iff_of_dvd_of_neg_of_neg {a b c d : Int} (hb : b < 0) (hd : d < 0)
     (hba : b ∣ a) (hdc : d ∣ c) : a / b ≤ c / d ↔ d * a ≤ c * b := by
   obtain ⟨⟨x, rfl⟩, y, rfl⟩ := hba, hdc
-  simp [*, Int.ne_of_lt, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
+  simp [*, Int.ne_of_lt, d.mul_assoc, b.mul_comm]
 
 theorem ediv_lt_ediv_iff_of_dvd_of_pos {a b c d : Int} (hb : 0 < b) (hd : 0 < d) (hba : b ∣ a)
     (hdc : d ∣ c) : a / b < c / d ↔ d * a < c * b := by
   obtain ⟨⟨x, rfl⟩, y, rfl⟩ := hba, hdc
-  simp [*, Int.ne_of_lt, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
+  simp [*, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
 
 theorem ediv_lt_ediv_iff_of_dvd_of_pos_of_neg {a b c d : Int} (hb : 0 < b) (hd : d < 0)
     (hba : b ∣ a) (hdc : d ∣ c) : a / b < c / d ↔ c * b < d * a := by
@@ -1731,7 +1733,7 @@ theorem ediv_lt_ediv_iff_of_dvd_of_neg_of_pos {a b c d : Int} (hb : b < 0) (hd :
 theorem ediv_lt_ediv_iff_of_dvd_of_neg_of_neg {a b c d : Int} (hb : b < 0) (hd : d < 0)
     (hba : b ∣ a) (hdc : d ∣ c) : a / b < c / d ↔ d * a < c * b := by
   obtain ⟨⟨x, rfl⟩, y, rfl⟩ := hba, hdc
-  simp [*, Int.ne_of_lt, Int.ne_of_gt, d.mul_assoc, b.mul_comm]
+  simp [*, Int.ne_of_lt, d.mul_assoc, b.mul_comm]
 
 /-! ### `tdiv` and ordering -/
 
@@ -2444,7 +2446,7 @@ theorem lt_mul_fdiv_self_add {x k : Int} (h : 0 < k) : x < k * (x.fdiv k) + k :=
 
 @[simp]
 theorem emod_bmod (x : Int) (n : Nat) : Int.bmod (x%n) n = Int.bmod x n := by
-  simp [bmod, Int.emod_emod]
+  simp [bmod]
 
 @[deprecated emod_bmod (since := "2025-04-11")]
 theorem emod_bmod_congr (x : Int) (n : Nat) : Int.bmod (x%n) n = Int.bmod x n :=
@@ -2745,7 +2747,7 @@ theorem bmod_lt {x : Int} {m : Nat} (h : 0 < m) : bmod x m < (m + 1) / 2 := by
   split
   · assumption
   · apply Int.lt_of_lt_of_le
-    · show _ < 0
+    · change _ < 0
       have : x % m < m := emod_lt_of_pos x (natCast_pos.mpr h)
       exact Int.sub_neg_of_lt this
     · exact Int.le.intro_sub _ rfl
@@ -2985,7 +2987,7 @@ theorem self_le_ediv_of_nonpos_of_nonneg {x y : Int} (hx : x ≤ 0) (hy : 0 ≤
   · simp [hx', zero_ediv]
   · by_cases hy : y = 0
     · simp [hy]; omega
-    · simp only [ge_iff_le, Int.le_ediv_iff_mul_le (c := y) (a := x) (b := x) (by omega),
+    · simp only [Int.le_ediv_iff_mul_le (c := y) (a := x) (b := x) (by omega),
         show (x * y ≤ x) = (x * y ≤ x * 1) by rw [Int.mul_one], Int.mul_one]
       apply Int.mul_le_mul_of_nonpos_left (a := x) (b := y) (c  := (1 : Int)) (by omega) (by omega)
 

src/Init/Data/Int/Gcd.lean

@@ -631,7 +631,7 @@ theorem lcm_mul_left_dvd_mul_lcm (k m n : Nat) : lcm (m * n) k ∣ lcm m k * lcm
   simpa [lcm_comm, Nat.mul_comm] using lcm_mul_right_dvd_mul_lcm _ _ _
 
 theorem lcm_dvd_mul_self_left_iff_dvd_mul {k n m : Nat} : lcm k n ∣ k * m ↔ n ∣ k * m := by
-  simp [← natAbs_dvd_natAbs, natAbs_mul, Nat.lcm_dvd_mul_self_left_iff_dvd_mul,
+  simp [Nat.lcm_dvd_mul_self_left_iff_dvd_mul,
     lcm_eq_natAbs_lcm_natAbs]
 
 theorem lcm_dvd_mul_self_right_iff_dvd_mul {k m n : Nat} : lcm n k ∣ m * k ↔ n ∣ m * k := by

src/Init/Data/Int/Lemmas.lean

@@ -339,7 +339,7 @@ protected theorem add_sub_assoc (a b c : Int) : a + b - c = a + (b - c) := by
   match m with
   | 0 => rfl
   | succ m =>
-    show ofNat (n - succ m) = subNatNat n (succ m)
+    change ofNat (n - succ m) = subNatNat n (succ m)
     rw [subNatNat, Nat.sub_eq_zero_of_le h]
 
 @[deprecated negSucc_eq (since := "2025-03-11")]
@@ -454,7 +454,7 @@ theorem negOfNat_eq_subNatNat_zero (n) : negOfNat n = subNatNat 0 n := by cases
 theorem ofNat_mul_subNatNat (m n k : Nat) :
     m * subNatNat n k = subNatNat (m * n) (m * k) := by
   cases m with
-  | zero => simp [ofNat_zero, Int.zero_mul, Nat.zero_mul, subNatNat_self]
+  | zero => simp [Int.zero_mul, Nat.zero_mul, subNatNat_self]
   | succ m => cases n.lt_or_ge k with
     | inl h =>
       have h' : succ m * n < succ m * k := Nat.mul_lt_mul_of_pos_left h (Nat.succ_pos m)

src/Init/Data/Int/Linear.lean

@@ -23,6 +23,7 @@ namespace Int.Linear
 abbrev Var := Nat
 abbrev Context := Lean.RArray Int
 
+@[expose]
 def Var.denote (ctx : Context) (v : Var) : Int :=
   ctx.get v
 
@@ -36,6 +37,7 @@ inductive Expr where
   | mulR (a : Expr) (k : Int)
   deriving Inhabited, BEq
 
+@[expose]
 def Expr.denote (ctx : Context) : Expr → Int
   | .add a b  => Int.add (denote ctx a) (denote ctx b)
   | .sub a b  => Int.sub (denote ctx a) (denote ctx b)
@@ -50,6 +52,7 @@ inductive Poly where
   | add (k : Int) (v : Var) (p : Poly)
   deriving BEq
 
+@[expose]
 def Poly.denote (ctx : Context) (p : Poly) : Int :=
   match p with
   | .num k => k
@@ -59,6 +62,7 @@ def Poly.denote (ctx : Context) (p : Poly) : Int :=
 Similar to `Poly.denote`, but produces a denotation better for `simp +arith`.
 Remark: we used to convert `Poly` back into `Expr` to achieve that.
 -/
+@[expose]
 def Poly.denote' (ctx : Context) (p : Poly) : Int :=
   match p with
   | .num k => k
@@ -75,8 +79,8 @@ where
 theorem Poly.denote'_go_eq_denote (ctx : Context) (p : Poly) (r : Int) : denote'.go ctx r p = p.denote ctx + r := by
   induction r, p using denote'.go.induct ctx <;> simp [denote'.go, denote]
   next => rw [Int.add_comm]
-  next ih => simp [denote'.go] at ih; rw [ih]; ac_rfl
-  next ih => simp [denote'.go] at ih; rw [ih]; ac_rfl
+  next ih => simp at ih; rw [ih]; ac_rfl
+  next ih => simp at ih; rw [ih]; ac_rfl
 
 theorem Poly.denote'_eq_denote (ctx : Context) (p : Poly) : p.denote' ctx = p.denote ctx := by
   unfold denote' <;> split <;> simp [denote, denote'_go_eq_denote] <;> ac_rfl
@@ -84,11 +88,13 @@ theorem Poly.denote'_eq_denote (ctx : Context) (p : Poly) : p.denote' ctx = p.de
 theorem Poly.denote'_add (ctx : Context) (a : Int) (x : Var) (p : Poly) : (Poly.add a x p).denote' ctx = a * x.denote ctx + p.denote ctx := by
   simp [Poly.denote'_eq_denote, denote]
 
+@[expose]
 def Poly.addConst (p : Poly) (k : Int) : Poly :=
   match p with
   | .num k' => .num (k+k')
   | .add k' v' p => .add k' v' (addConst p k)
 
+@[expose]
 def Poly.insert (k : Int) (v : Var) (p : Poly) : Poly :=
   match p with
   | .num k' => .add k v (.num k')
@@ -104,16 +110,19 @@ def Poly.insert (k : Int) (v : Var) (p : Poly) : Poly :=
       .add k' v' (insert k v p)
 
 /-- Normalizes the given polynomial by fusing monomial and constants. -/
+@[expose]
 def Poly.norm (p : Poly) : Poly :=
   match p with
   | .num k => .num k
   | .add k v p => (norm p).insert k v
 
+@[expose]
 def Poly.append (p₁ p₂ : Poly) : Poly :=
   match p₁ with
   | .num k₁ => p₂.addConst k₁
   | .add k x p₁ => .add k x (append p₁ p₂)
 
+@[expose]
 def Poly.combine' (fuel : Nat) (p₁ p₂ : Poly) : Poly :=
   match fuel with
   | 0 => p₁.append p₂
@@ -133,10 +142,12 @@ def Poly.combine' (fuel : Nat) (p₁ p₂ : Poly) : Poly :=
     else
       .add a₂ x₂ (combine' fuel (.add a₁ x₁ p₁) p₂)
 
+@[expose]
 def Poly.combine (p₁ p₂ : Poly) : Poly :=
   combine' 100000000 p₁ p₂
 
 /-- Converts the given expression into a polynomial. -/
+@[expose]
 def Expr.toPoly' (e : Expr) : Poly :=
   go 1 e (.num 0)
 where
@@ -150,6 +161,7 @@ where
     | .neg a    => go (-coeff) a
 
 /-- Converts the given expression into a polynomial, and then normalizes it. -/
+@[expose]
 def Expr.norm (e : Expr) : Poly :=
   e.toPoly'.norm
 
@@ -159,6 +171,7 @@ Examples:
 - `cdiv 7 3` returns `3`
 - `cdiv (-7) 3` returns `-2`.
 -/
+@[expose]
 def cdiv (a b : Int) : Int :=
   -((-a)/b)
 
@@ -173,6 +186,7 @@ See theorem `cdiv_add_cmod`. We also have
 -b < cmod a b ≤ 0
 ```
 -/
+@[expose]
 def cmod (a b : Int) : Int :=
   -((-a)%b)
 
@@ -219,6 +233,7 @@ theorem cdiv_eq_div_of_divides {a b : Int} (h : a % b = 0) : a/b = cdiv a b := b
   next => rw [Int.mul_eq_mul_right_iff h] at this; assumption
 
 /-- Returns the constant of the given linear polynomial. -/
+@[expose]
 def Poly.getConst : Poly → Int
   | .num k => k
   | .add _ _ p => getConst p
@@ -230,6 +245,7 @@ Notes:
 - We only use this function with `k`s that divides all coefficients.
 - We use `cdiv` for the constant to implement the inequality tightening rule.
 -/
+@[expose]
 def Poly.div (k : Int) : Poly → Poly
   | .num k' => .num (cdiv k' k)
   | .add k' x p => .add (k'/k) x (div k p)
@@ -238,6 +254,7 @@ def Poly.div (k : Int) : Poly → Poly
 Returns `true` if `k` divides all coefficients and the constant of the given
 linear polynomial.
 -/
+@[expose]
 def Poly.divAll (k : Int) : Poly → Bool
   | .num k' => k' % k == 0
   | .add k' _ p => k' % k == 0 && divAll k p
@@ -245,6 +262,7 @@ def Poly.divAll (k : Int) : Poly → Bool
 /--
 Returns `true` if `k` divides all coefficients of the given linear polynomial.
 -/
+@[expose]
 def Poly.divCoeffs (k : Int) : Poly → Bool
   | .num _ => true
   | .add k' _ p => k' % k == 0 && divCoeffs k p
@@ -252,11 +270,13 @@ def Poly.divCoeffs (k : Int) : Poly → Bool
 /--
 `p.mul k` multiplies all coefficients and constant of the polynomial `p` by `k`.
 -/
+@[expose]
 def Poly.mul' (p : Poly) (k : Int) : Poly :=
   match p with
   | .num k' => .num (k*k')
   | .add k' v p => .add (k*k') v (mul' p k)
 
+@[expose]
 def Poly.mul (p : Poly) (k : Int) : Poly :=
   if k == 0 then
     .num 0
@@ -343,7 +363,7 @@ theorem Expr.denote_toPoly'_go (ctx : Context) (e : Expr) :
     simp [eq_of_beq h]
   | case2 k k' h =>
     simp only [toPoly'.go, h, cond_false]
-    simp [Var.denote]
+    simp
   | case3 k i => simp [toPoly'.go]
   | case4 k a b iha ihb => simp [toPoly'.go, iha, ihb]
   | case5 k a b iha ihb =>
@@ -351,7 +371,7 @@ theorem Expr.denote_toPoly'_go (ctx : Context) (e : Expr) :
     rw [Int.sub_eq_add_neg, ←Int.neg_mul, Int.add_assoc]
   | case6 k k' a h
   | case8 k a k' h =>
-    simp only [toPoly'.go, h, cond_false]
+    simp only [toPoly'.go, h]
     simp [eq_of_beq h]
   | case7 k a k' h ih =>
     simp only [toPoly'.go, h, cond_false]
@@ -383,9 +403,10 @@ attribute [local simp] Poly.denote'_eq_denote
 
 theorem Expr.eq_of_norm_eq (ctx : Context) (e : Expr) (p : Poly) (h : e.norm == p) : e.denote ctx = p.denote' ctx := by
   have h := congrArg (Poly.denote ctx) (eq_of_beq h)
-  simp [Poly.norm] at h
+  simp at h
   simp [*]
 
+@[expose]
 def norm_eq_cert (lhs rhs : Expr) (p : Poly) : Bool :=
   p == (lhs.sub rhs).norm
 
@@ -401,6 +422,7 @@ theorem norm_le (ctx : Context) (lhs rhs : Expr) (p : Poly) (h : norm_eq_cert lh
   · exact Int.sub_nonpos_of_le
   · exact Int.le_of_sub_nonpos
 
+@[expose]
 def norm_eq_var_cert (lhs rhs : Expr) (x y : Var) : Bool :=
   (lhs.sub rhs).norm == .add 1 x (.add (-1) y (.num 0))
 
@@ -411,6 +433,7 @@ theorem norm_eq_var (ctx : Context) (lhs rhs : Expr) (x y : Var) (h : norm_eq_va
   simp at h
   rw [←Int.sub_eq_zero, h, ← @Int.sub_eq_zero (Var.denote ctx x), Int.sub_eq_add_neg]
 
+@[expose]
 def norm_eq_var_const_cert (lhs rhs : Expr) (x : Var) (k : Int) : Bool :=
   (lhs.sub rhs).norm == .add 1 x (.num (-k))
 
@@ -429,6 +452,7 @@ private theorem mul_eq_zero_iff (a k : Int) (h₁ : k > 0) : k * a = 0 ↔ a = 0
 theorem norm_eq_coeff' (ctx : Context) (p p' : Poly) (k : Int) : p = p'.mul k → k > 0 → (p.denote ctx = 0 ↔ p'.denote ctx = 0) := by
   intro; subst p; intro h; simp [mul_eq_zero_iff, *]
 
+@[expose]
 def norm_eq_coeff_cert (lhs rhs : Expr) (p : Poly) (k : Int) : Bool :=
   (lhs.sub rhs).norm == p.mul k && k > 0
 
@@ -448,7 +472,7 @@ private theorem mul_le_zero_iff (a k : Int) (h₁ : k > 0) : k * a ≤ 0 ↔ a
     simp at h; assumption
 
 private theorem norm_le_coeff' (ctx : Context) (p p' : Poly) (k : Int) : p = p'.mul k → k > 0 → (p.denote ctx ≤ 0 ↔ p'.denote ctx ≤ 0) := by
-  simp [norm_eq_coeff_cert]
+  simp
   intro; subst p; intro h; simp [mul_le_zero_iff, *]
 
 theorem norm_le_coeff (ctx : Context) (lhs rhs : Expr) (p : Poly) (k : Int)
@@ -492,6 +516,7 @@ private theorem eq_of_norm_eq_of_divCoeffs {ctx : Context} {p₁ p₂ : Poly} {k
   apply mul_add_cmod_le_iff
   assumption
 
+@[expose]
 def norm_le_coeff_tight_cert (lhs rhs : Expr) (p : Poly) (k : Int) : Bool :=
   let p' := lhs.sub rhs |>.norm
   k > 0 && (p'.divCoeffs k && p == p'.div k)
@@ -502,11 +527,13 @@ theorem norm_le_coeff_tight (ctx : Context) (lhs rhs : Expr) (p : Poly) (k : Int
   rw [norm_le ctx lhs rhs (lhs.sub rhs).norm BEq.rfl, Poly.denote'_eq_denote]
   apply eq_of_norm_eq_of_divCoeffs
 
+@[expose]
 def Poly.isUnsatEq (p : Poly) : Bool :=
   match p with
   | .num k => k != 0
   | _ => false
 
+@[expose]
 def Poly.isValidEq (p : Poly) : Bool :=
   match p with
   | .num k => k == 0
@@ -530,11 +557,13 @@ theorem eq_eq_true (ctx : Context) (lhs rhs : Expr) : (lhs.sub rhs).norm.isValid
     rw [← Int.sub_eq_zero, h]
     assumption
 
+@[expose]
 def Poly.isUnsatLe (p : Poly) : Bool :=
   match p with
   | .num k => k > 0
   | _ => false
 
+@[expose]
 def Poly.isValidLe (p : Poly) : Bool :=
   match p with
   | .num k => k ≤ 0
@@ -595,6 +624,7 @@ private theorem poly_eq_zero_eq_false (ctx : Context) {p : Poly} {k : Int} : p.d
   have high := h₃
   exact contra h₂ low high this
 
+@[expose]
 def unsatEqDivCoeffCert (lhs rhs : Expr) (k : Int) : Bool :=
   let p := (lhs.sub rhs).norm
   p.divCoeffs k && k > 0 && cmod p.getConst k < 0
@@ -621,6 +651,7 @@ private theorem gcd_dvd_step {k a b x : Int} (h : k ∣ a*x + b) : gcd a k ∣ b
   have h₂ : gcd a k ∣ a*x := Int.dvd_trans (gcd_dvd_left a k) (Int.dvd_mul_right a x)
   exact Int.dvd_iff_dvd_of_dvd_add h₁ |>.mp h₂
 
+@[expose]
 def Poly.gcdCoeffs : Poly → Int → Int
   | .num _, k => k
   | .add k' _ p, k => gcdCoeffs p (gcd k' k)
@@ -631,6 +662,7 @@ theorem Poly.gcd_dvd_const {ctx : Context} {p : Poly} {k : Int} (h : k ∣ p.den
     rw [Int.add_comm] at h
     exact ih (gcd_dvd_step h)
 
+@[expose]
 def Poly.isUnsatDvd (k : Int) (p : Poly) : Bool :=
   p.getConst % p.gcdCoeffs k != 0
 
@@ -668,9 +700,11 @@ theorem dvd_eq_false (ctx : Context) (k : Int) (e : Expr) (h : e.norm.isUnsatDvd
   rw [norm_dvd ctx k e e.norm BEq.rfl]
   apply dvd_eq_false' ctx k e.norm h
 
+@[expose]
 def dvd_coeff_cert (k₁ : Int) (p₁ : Poly) (k₂ : Int) (p₂ : Poly) (k : Int) : Bool :=
   k != 0 && (k₁ == k*k₂ && p₁ == p₂.mul k)
 
+@[expose]
 def norm_dvd_gcd_cert (k₁ : Int) (e₁ : Expr) (k₂ : Int) (p₂ : Poly) (k : Int) : Bool :=
   dvd_coeff_cert k₁ e₁.norm k₂ p₂ k
 
@@ -702,6 +736,7 @@ private theorem dvd_gcd_of_dvd (d a x p : Int) (h : d ∣ a * x + p) : gcd d a
   rw [Int.mul_assoc, Int.mul_assoc, ← Int.mul_sub] at h
   exists k₁ * k - k₂ * x
 
+@[expose]
 def dvd_elim_cert (k₁ : Int) (p₁ : Poly) (k₂ : Int) (p₂ : Poly) : Bool :=
   match p₁ with
   | .add a _ p => k₂ == gcd k₁ a && p₂ == p
@@ -764,6 +799,7 @@ private theorem dvd_solve_elim' {x : Int} {d₁ a₁ p₁ : Int} {d₂ a₂ p₂
  rw [h₃, h₄, Int.mul_assoc, Int.mul_assoc, ←Int.mul_sub] at this
  exact ⟨k₄ * k₁ - k₃ * k₂, this⟩
 
+@[expose]
 def dvd_solve_combine_cert (d₁ : Int) (p₁ : Poly) (d₂ : Int) (p₂ : Poly) (d : Int) (p : Poly) (g α β : Int) : Bool :=
   match p₁, p₂ with
   | .add a₁ x₁ p₁, .add a₂ x₂ p₂ =>
@@ -779,12 +815,13 @@ theorem dvd_solve_combine (ctx : Context) (d₁ : Int) (p₁ : Poly) (d₂ : Int
   split <;> simp
   next a₁ x₁ p₁ a₂ x₂ p₂ =>
   intro _ hg hd hp; subst x₁ p
-  simp [Poly.denote'_add]
+  simp
   intro h₁ h₂
   rw [Int.add_comm] at h₁ h₂
   rw [Int.add_comm _ (g * x₂.denote ctx), Int.add_left_comm, ← Int.add_assoc, hd]
   exact dvd_solve_combine' hg.symm h₁ h₂
 
+@[expose]
 def dvd_solve_elim_cert (d₁ : Int) (p₁ : Poly) (d₂ : Int) (p₂ : Poly) (d : Int) (p : Poly) : Bool :=
   match p₁, p₂ with
   | .add a₁ x₁ p₁, .add a₂ x₂ p₂ =>
@@ -816,6 +853,7 @@ theorem le_norm (ctx : Context) (p₁ p₂ : Poly) (h : p₁.norm == p₂) : p
   simp at h
   simp [*]
 
+@[expose]
 def le_coeff_cert (p₁ p₂ : Poly) (k : Int) : Bool :=
   k > 0 && (p₁.divCoeffs k && p₂ == p₁.div k)
 
@@ -824,6 +862,7 @@ theorem le_coeff (ctx : Context) (p₁ p₂ : Poly) (k : Int) : le_coeff_cert p
   intro h₁ h₂ h₃
   exact eq_of_norm_eq_of_divCoeffs h₁ h₂ h₃ |>.mp
 
+@[expose]
 def le_neg_cert (p₁ p₂ : Poly) : Bool :=
   p₂ == (p₁.mul (-1) |>.addConst 1)
 
@@ -834,11 +873,13 @@ theorem le_neg (ctx : Context) (p₁ p₂ : Poly) : le_neg_cert p₁ p₂ → ¬
   simp at h
   exact h
 
+@[expose]
 def Poly.leadCoeff (p : Poly) : Int :=
   match p with
   | .add a _ _ => a
   | _ => 1
 
+@[expose]
 def le_combine_cert (p₁ p₂ p₃ : Poly) : Bool :=
   let a₁ := p₁.leadCoeff.natAbs
   let a₂ := p₂.leadCoeff.natAbs
@@ -854,6 +895,7 @@ theorem le_combine (ctx : Context) (p₁ p₂ p₃ : Poly)
   · rw [← Int.zero_mul (Poly.denote ctx p₂)]; apply Int.mul_le_mul_of_nonpos_right <;> simp [*]
   · rw [← Int.zero_mul (Poly.denote ctx p₁)]; apply Int.mul_le_mul_of_nonpos_right <;> simp [*]
 
+@[expose]
 def le_combine_coeff_cert (p₁ p₂ p₃ : Poly) (k : Int) : Bool :=
   let a₁ := p₁.leadCoeff.natAbs
   let a₂ := p₂.leadCoeff.natAbs
@@ -883,6 +925,7 @@ theorem eq_norm (ctx : Context) (p₁ p₂ : Poly) (h : p₁.norm == p₂) : p
   simp at h
   simp [*]
 
+@[expose]
 def eq_coeff_cert (p p' : Poly) (k : Int) : Bool :=
   p == p'.mul k && k > 0
 
@@ -893,6 +936,7 @@ theorem eq_coeff (ctx : Context) (p p' : Poly) (k : Int) : eq_coeff_cert p p' k
 theorem eq_unsat (ctx : Context) (p : Poly) : p.isUnsatEq → p.denote' ctx = 0 → False := by
   simp [Poly.isUnsatEq] <;> split <;> simp
 
+@[expose]
 def eq_unsat_coeff_cert (p : Poly) (k : Int) : Bool :=
   p.divCoeffs k && k > 0 && cmod p.getConst k < 0
 
@@ -902,6 +946,7 @@ theorem eq_unsat_coeff (ctx : Context) (p : Poly) (k : Int) : eq_unsat_coeff_cer
   have h := poly_eq_zero_eq_false ctx h₁ h₂ h₃; clear h₁ h₂ h₃
   simp [h]
 
+@[expose]
 def Poly.coeff (p : Poly) (x : Var) : Int :=
   match p with
   | .add a y p => bif x == y then a else coeff p x
@@ -916,7 +961,8 @@ private theorem dvd_of_eq' {a x p : Int} : a*x + p = 0 → a ∣ p := by
   rw [Int.mul_comm, ← Int.neg_mul, Eq.comm, Int.mul_comm] at h
   exact ⟨-x, h⟩
 
-private def abs (x : Int) : Int :=
+@[expose]
+def abs (x : Int) : Int :=
   Int.ofNat x.natAbs
 
 private theorem abs_dvd {a p : Int} (h : a ∣ p) : abs a ∣ p := by
@@ -924,6 +970,7 @@ private theorem abs_dvd {a p : Int} (h : a ∣ p) : abs a ∣ p := by
   · simp at h; assumption
   · simp [Int.negSucc_eq] at h; assumption
 
+@[expose]
 def dvd_of_eq_cert (x : Var) (p₁ : Poly) (d₂ : Int) (p₂ : Poly) : Bool :=
   let a := p₁.coeff x
   d₂ == abs a && p₂ == p₁.insert (-a) x
@@ -950,6 +997,7 @@ private theorem eq_dvd_subst' {a x p d b q : Int} : a*x + p = 0 → d ∣ b*x +
   rw [← Int.mul_assoc] at h
   exact ⟨z, h⟩
 
+@[expose]
 def eq_dvd_subst_cert (x : Var) (p₁ : Poly) (d₂ : Int) (p₂ : Poly) (d₃ : Int) (p₃ : Poly) : Bool :=
   let a := p₁.coeff x
   let b := p₂.coeff x
@@ -979,6 +1027,7 @@ theorem eq_dvd_subst (ctx : Context) (x : Var) (p₁ : Poly) (d₂ : Int) (p₂
   apply abs_dvd
   simp [this, Int.neg_mul]
 
+@[expose]
 def eq_eq_subst_cert (x : Var) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   let a := p₁.coeff x
   let b := p₂.coeff x
@@ -991,6 +1040,7 @@ theorem eq_eq_subst (ctx : Context) (x : Var) (p₁ : Poly) (p₂ : Poly) (p₃
   intro h₁ h₂
   simp [*]
 
+@[expose]
 def eq_le_subst_nonneg_cert (x : Var) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   let a := p₁.coeff x
   let b := p₂.coeff x
@@ -1006,6 +1056,7 @@ theorem eq_le_subst_nonneg (ctx : Context) (x : Var) (p₁ : Poly) (p₂ : Poly)
   simp at h₂
   simp [*]
 
+@[expose]
 def eq_le_subst_nonpos_cert (x : Var) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   let a := p₁.coeff x
   let b := p₂.coeff x
@@ -1022,6 +1073,7 @@ theorem eq_le_subst_nonpos (ctx : Context) (x : Var) (p₁ : Poly) (p₂ : Poly)
   rw [Int.mul_comm]
   assumption
 
+@[expose]
 def eq_of_core_cert (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   p₃ == p₁.combine (p₂.mul (-1))
 
@@ -1031,6 +1083,7 @@ theorem eq_of_core (ctx : Context) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly)
   intro; subst p₃; simp
   intro h; rw [h, Int.add_neg_eq_sub, Int.sub_self]
 
+@[expose]
 def Poly.isUnsatDiseq (p : Poly) : Bool :=
   match p with
   | .num 0 => true
@@ -1047,11 +1100,12 @@ theorem diseq_coeff (ctx : Context) (p p' : Poly) (k : Int) : eq_coeff_cert p p'
   intro _ _; simp [mul_eq_zero_iff, *]
 
 theorem diseq_neg (ctx : Context) (p p' : Poly) : p' == p.mul (-1) → p.denote' ctx ≠ 0 → p'.denote' ctx ≠ 0 := by
-  simp; intro _ _; simp [mul_eq_zero_iff, *]
+  simp; intro _ _; simp [*]
 
 theorem diseq_unsat (ctx : Context) (p : Poly) : p.isUnsatDiseq → p.denote' ctx ≠ 0 → False := by
   simp [Poly.isUnsatDiseq] <;> split <;> simp
 
+@[expose]
 def diseq_eq_subst_cert (x : Var) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   let a := p₁.coeff x
   let b := p₂.coeff x
@@ -1071,6 +1125,7 @@ theorem diseq_of_core (ctx : Context) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly)
   intro h; rw [← Int.sub_eq_zero] at h
   rw [Int.add_neg_eq_sub]; assumption
 
+@[expose]
 def eq_of_le_ge_cert (p₁ p₂ : Poly) : Bool :=
   p₂ == p₁.mul (-1)
 
@@ -1081,6 +1136,7 @@ theorem eq_of_le_ge (ctx : Context) (p₁ : Poly) (p₂ : Poly)
   intro h₁ h₂
   simp [Int.eq_iff_le_and_ge, *]
 
+@[expose]
 def le_of_le_diseq_cert (p₁ : Poly) (p₂ : Poly) (p₃ : Poly) : Bool :=
   -- Remark: we can generate two different certificates in the future, and avoid the `||` in the certificate.
   (p₂ == p₁ || p₂ == p₁.mul (-1)) &&
@@ -1095,6 +1151,7 @@ theorem le_of_le_diseq (ctx : Context) (p₁ : Poly) (p₂ : Poly) (p₃ : Poly)
     next h => have := Int.lt_of_le_of_lt h₁ h; simp at this
   intro h; cases h <;> intro <;> subst p₂ p₃ <;> simp <;> apply this
 
+@[expose]
 def diseq_split_cert (p₁ p₂ p₃ : Poly) : Bool :=
   p₂ == p₁.addConst 1 &&
   p₃ == (p₁.mul (-1)).addConst 1
@@ -1113,6 +1170,7 @@ theorem diseq_split_resolve (ctx : Context) (p₁ p₂ p₃ : Poly)
   intro h₁ h₂ h₃
   exact (diseq_split ctx p₁ p₂ p₃ h₁ h₂).resolve_left h₃
 
+@[expose]
 def OrOver (n : Nat) (p : Nat → Prop) : Prop :=
   match n with
   | 0 => False
@@ -1127,6 +1185,7 @@ theorem orOver_resolve {n p} : OrOver (n+1) p → ¬ p n → OrOver n p := by
   · contradiction
   · assumption
 
+@[expose]
 def OrOver_cases_type (n : Nat) (p : Nat → Prop) : Prop :=
   match n with
   | 0 => p 0
@@ -1186,6 +1245,7 @@ private theorem cooper_dvd_left_core
   rw [this] at h₃
   exists k.toNat
 
+@[expose]
 def cooper_dvd_left_cert (p₁ p₂ p₃ : Poly) (d : Int) (n : Nat) : Bool :=
   p₁.casesOn (fun _ => false) fun a x _ =>
   p₂.casesOn (fun _ => false) fun b y _ =>
@@ -1194,11 +1254,13 @@ def cooper_dvd_left_cert (p₁ p₂ p₃ : Poly) (d : Int) (n : Nat) : Bool :=
    .and (a < 0)  <| .and (b > 0)  <|
    .and (d > 0)  <| n == Int.lcm a (a * d / Int.gcd (a * d) c)
 
+@[expose]
 def Poly.tail (p : Poly) : Poly :=
   match p with
   | .add _ _ p => p
   | _ => p
 
+@[expose]
 def cooper_dvd_left_split (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (k : Nat) : Prop :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1238,6 +1300,7 @@ theorem cooper_dvd_left (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (n : N
  simp only [denote'_addConst_eq]
  exact cooper_dvd_left_core ha hb hd h₁ h₂ h₃
 
+@[expose]
 def cooper_dvd_left_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (b : Int) (p' : Poly) : Bool :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1248,8 +1311,9 @@ def cooper_dvd_left_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (b : Int) (p' :
 theorem cooper_dvd_left_split_ineq (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (k : Nat) (b : Int) (p' : Poly)
     : cooper_dvd_left_split ctx p₁ p₂ p₃ d k → cooper_dvd_left_split_ineq_cert p₁ p₂ k b p' → p'.denote' ctx ≤ 0 := by
   simp [cooper_dvd_left_split_ineq_cert, cooper_dvd_left_split]
-  intros; subst p' b; simp [denote'_mul_combine_mul_addConst_eq]; assumption
+  intros; subst p' b; simp; assumption
 
+@[expose]
 def cooper_dvd_left_split_dvd1_cert (p₁ p' : Poly) (a : Int) (k : Int) : Bool :=
   a == p₁.leadCoeff && p' == p₁.tail.addConst k
 
@@ -1258,6 +1322,7 @@ theorem cooper_dvd_left_split_dvd1 (ctx : Context) (p₁ p₂ p₃ : Poly) (d :
   simp [cooper_dvd_left_split_dvd1_cert, cooper_dvd_left_split]
   intros; subst a p'; simp; assumption
 
+@[expose]
 def cooper_dvd_left_split_dvd2_cert (p₁ p₃ : Poly) (d : Int) (k : Nat) (d' : Int) (p' : Poly): Bool :=
   let p  := p₁.tail
   let s  := p₃.tail
@@ -1283,16 +1348,18 @@ private theorem cooper_left_core
   have h := cooper_dvd_left_core a_neg b_pos d_pos h₁ h₂ h₃
   simp only [Int.mul_one, gcd_zero, ofNat_natAbs_of_nonpos (Int.le_of_lt a_neg), Int.ediv_neg,
     Int.ediv_self (Int.ne_of_lt a_neg), Int.reduceNeg, lcm_neg_right, lcm_one,
-    Int.add_left_comm, Int.zero_mul, Int.mul_zero, Int.add_zero, Int.dvd_zero,
+    Int.zero_mul, Int.mul_zero, Int.add_zero, Int.dvd_zero,
     and_true] at h
   assumption
 
+@[expose]
 def cooper_left_cert (p₁ p₂ : Poly) (n : Nat) : Bool :=
   p₁.casesOn (fun _ => false) fun a x _ =>
   p₂.casesOn (fun _ => false) fun b y _ =>
    .and (x == y) <| .and (a < 0)  <| .and (b > 0)  <|
    n == a.natAbs
 
+@[expose]
 def cooper_left_split (ctx : Context) (p₁ p₂ : Poly) (k : Nat) : Prop :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1320,6 +1387,7 @@ theorem cooper_left (ctx : Context) (p₁ p₂ : Poly) (n : Nat)
  simp only [denote'_addConst_eq]
  assumption
 
+@[expose]
 def cooper_left_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (b : Int) (p' : Poly) : Bool :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1330,8 +1398,9 @@ def cooper_left_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (b : Int) (p' : Pol
 theorem cooper_left_split_ineq (ctx : Context) (p₁ p₂ : Poly) (k : Nat) (b : Int) (p' : Poly)
     : cooper_left_split ctx p₁ p₂ k → cooper_left_split_ineq_cert p₁ p₂ k b p' → p'.denote' ctx ≤ 0 := by
   simp [cooper_left_split_ineq_cert, cooper_left_split]
-  intros; subst p' b; simp [denote'_mul_combine_mul_addConst_eq]; assumption
+  intros; subst p' b; simp; assumption
 
+@[expose]
 def cooper_left_split_dvd_cert (p₁ p' : Poly) (a : Int) (k : Int) : Bool :=
   a == p₁.leadCoeff && p' == p₁.tail.addConst k
 
@@ -1353,7 +1422,7 @@ private theorem cooper_dvd_right_core
   have h₁'    : p ≤ (-a)*x := by rw [Int.neg_mul, ← Lean.Omega.Int.add_le_zero_iff_le_neg']; assumption
   have h₂'    : b * x ≤ -q := by rw [← Lean.Omega.Int.add_le_zero_iff_le_neg', Int.add_comm]; assumption
   have ⟨k, h₁, h₂, h₃, h₄, h₅⟩ := Int.cooper_resolution_dvd_right a_pos' b_pos d_pos |>.mp ⟨x, h₁', h₂', h₃⟩
-  simp only [Int.neg_mul, neg_gcd, lcm_neg_left, Int.mul_neg, Int.neg_neg, Int.neg_dvd] at *
+  simp only [Int.neg_mul, Int.mul_neg, Int.neg_neg] at *
   apply orOver_of_exists
   have hlt := ofNat_lt h₁ h₂
   replace h₃ := Int.add_le_add_right h₃ (-(a*q)); rw [Int.add_right_neg] at h₃
@@ -1363,8 +1432,9 @@ private theorem cooper_dvd_right_core
   have : -(c * k) + -(c * q) + b * s = -(c * q) + b * s + -(c * k) := by ac_rfl
   rw [this] at h₅; clear this
   exists k.toNat
-  simp only [hlt, true_and, and_true, cast_toNat h₁, h₃, h₄, h₅]
+  simp only [hlt, and_true, cast_toNat h₁, h₃, h₄, h₅]
 
+@[expose]
 def cooper_dvd_right_cert (p₁ p₂ p₃ : Poly) (d : Int) (n : Nat) : Bool :=
   p₁.casesOn (fun _ => false) fun a x _ =>
   p₂.casesOn (fun _ => false) fun b y _ =>
@@ -1373,6 +1443,7 @@ def cooper_dvd_right_cert (p₁ p₂ p₃ : Poly) (d : Int) (n : Nat) : Bool :=
    .and (a < 0)  <| .and (b > 0)  <|
    .and (d > 0)  <| n == Int.lcm b (b * d / Int.gcd (b * d) c)
 
+@[expose]
 def cooper_dvd_right_split (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (k : Nat) : Prop :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1402,9 +1473,10 @@ theorem cooper_dvd_right (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (n :
  intro h₁ h₂ h₃
  have := cooper_dvd_right_core ha hb hd h₁ h₂ h₃
  simp only [denote'_mul_combine_mul_addConst_eq]
- simp only [denote'_addConst_eq, ←Int.neg_mul]
+ simp only [denote'_addConst_eq]
  exact cooper_dvd_right_core ha hb hd h₁ h₂ h₃
 
+@[expose]
 def cooper_dvd_right_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (a : Int) (p' : Poly) : Bool :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1415,8 +1487,9 @@ def cooper_dvd_right_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (a : Int) (p'
 theorem cooper_dvd_right_split_ineq (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (k : Nat) (a : Int) (p' : Poly)
     : cooper_dvd_right_split ctx p₁ p₂ p₃ d k → cooper_dvd_right_split_ineq_cert p₁ p₂ k a p' → p'.denote' ctx ≤ 0 := by
   simp [cooper_dvd_right_split_ineq_cert, cooper_dvd_right_split]
-  intros; subst a p'; simp [denote'_mul_combine_mul_addConst_eq]; assumption
+  intros; subst a p'; simp; assumption
 
+@[expose]
 def cooper_dvd_right_split_dvd1_cert (p₂ p' : Poly) (b : Int) (k : Int) : Bool :=
   b == p₂.leadCoeff && p' == p₂.tail.addConst k
 
@@ -1425,6 +1498,7 @@ theorem cooper_dvd_right_split_dvd1 (ctx : Context) (p₁ p₂ p₃ : Poly) (d :
   simp [cooper_dvd_right_split_dvd1_cert, cooper_dvd_right_split]
   intros; subst b p'; simp; assumption
 
+@[expose]
 def cooper_dvd_right_split_dvd2_cert (p₂ p₃ : Poly) (d : Int) (k : Nat) (d' : Int) (p' : Poly): Bool :=
   let q  := p₂.tail
   let s  := p₃.tail
@@ -1448,17 +1522,19 @@ private theorem cooper_right_core
   have d_pos : (0 : Int) < 1 := by decide
   have h₃ : 1 ∣ 0*x + 0 := Int.one_dvd _
   have h := cooper_dvd_right_core a_neg b_pos d_pos h₁ h₂ h₃
-  simp only [Int.mul_one, gcd_zero, Int.natAbs_of_nonneg (Int.le_of_lt b_pos), Int.ediv_neg,
-    Int.ediv_self (Int.ne_of_gt b_pos), Int.reduceNeg, lcm_neg_right, lcm_one,
-    Int.add_left_comm, Int.zero_mul, Int.mul_zero, Int.add_zero, Int.dvd_zero,
+  simp only [Int.mul_one, gcd_zero, Int.natAbs_of_nonneg (Int.le_of_lt b_pos), 
+    Int.ediv_self (Int.ne_of_gt b_pos), lcm_one,
+    Int.zero_mul, Int.mul_zero, Int.add_zero, Int.dvd_zero,
     and_true, Int.neg_zero] at h
   assumption
 
+@[expose]
 def cooper_right_cert (p₁ p₂ : Poly) (n : Nat) : Bool :=
   p₁.casesOn (fun _ => false) fun a x _ =>
   p₂.casesOn (fun _ => false) fun b y _ =>
   .and (x == y) <| .and (a < 0)  <| .and (b > 0) <| n == b.natAbs
 
+@[expose]
 def cooper_right_split (ctx : Context) (p₁ p₂ : Poly) (k : Nat) : Prop :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1483,9 +1559,10 @@ theorem cooper_right (ctx : Context) (p₁ p₂ : Poly) (n : Nat)
  intro h₁ h₂
  have := cooper_right_core ha hb h₁ h₂
  simp only [denote'_mul_combine_mul_addConst_eq]
- simp only [denote'_addConst_eq, ←Int.neg_mul]
+ simp only [denote'_addConst_eq]
  assumption
 
+@[expose]
 def cooper_right_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (a : Int) (p' : Poly) : Bool :=
   let p  := p₁.tail
   let q  := p₂.tail
@@ -1496,8 +1573,9 @@ def cooper_right_split_ineq_cert (p₁ p₂ : Poly) (k : Int) (a : Int) (p' : Po
 theorem cooper_right_split_ineq (ctx : Context) (p₁ p₂ : Poly) (k : Nat) (a : Int) (p' : Poly)
     : cooper_right_split ctx p₁ p₂ k → cooper_right_split_ineq_cert p₁ p₂ k a p' → p'.denote' ctx ≤ 0 := by
   simp [cooper_right_split_ineq_cert, cooper_right_split]
-  intros; subst a p'; simp [denote'_mul_combine_mul_addConst_eq]; assumption
+  intros; subst a p'; simp; assumption
 
+@[expose]
 def cooper_right_split_dvd_cert (p₂ p' : Poly) (b : Int) (k : Int) : Bool :=
   b == p₂.leadCoeff && p' == p₂.tail.addConst k
 
@@ -1587,6 +1665,7 @@ abbrev Poly.casesOnAdd (p : Poly) (k : Int → Var → Poly → Bool) : Bool :=
 abbrev Poly.casesOnNum (p : Poly) (k : Int → Bool) : Bool :=
   p.casesOn k (fun _ _ _ => false)
 
+@[expose]
 def cooper_unsat_cert (p₁ p₂ p₃ : Poly) (d : Int) (α β : Int) : Bool :=
   p₁.casesOnAdd fun k₁ x p₁ =>
   p₂.casesOnAdd fun k₂ y p₂ =>
@@ -1603,7 +1682,7 @@ theorem cooper_unsat (ctx : Context) (p₁ p₂ p₃ : Poly) (d : Int) (α β :
    : cooper_unsat_cert p₁ p₂ p₃ d α β →
      p₁.denote' ctx ≤ 0 → p₂.denote' ctx ≤ 0 → d ∣ p₃.denote' ctx → False := by
   unfold cooper_unsat_cert <;> cases p₁ <;> cases p₂ <;> cases p₃ <;> simp only [Poly.casesOnAdd,
-    Bool.false_eq_true, Poly.denote'_add, mul_def, add_def, false_implies]
+    Bool.false_eq_true, Poly.denote'_add, false_implies]
   next k₁ x p₁ k₂ y p₂ c z p₃ =>
   cases p₁ <;> cases p₂ <;> cases p₃ <;> simp only [Poly.casesOnNum, Int.reduceNeg,
     Bool.and_eq_true, beq_iff_eq, decide_eq_true_eq, and_imp, Bool.false_eq_true,
@@ -1626,6 +1705,7 @@ theorem emod_nonneg (x y : Int) : y != 0 → -1 * (x % y) ≤ 0 := by
   simp at this
   assumption
 
+@[expose]
 def emod_le_cert (y n : Int) : Bool :=
   y != 0 && n == 1 - y.natAbs
 
@@ -1665,7 +1745,7 @@ theorem natCast_sub (x y : Nat)
         (NatCast.natCast x : Int) + -1*NatCast.natCast y
       else
         (0 : Int) := by
-  show (↑(x - y) : Int) = if (↑y : Int) + (-1)*↑x ≤ 0 then ↑x + (-1)*↑y else 0
+  change (↑(x - y) : Int) = if (↑y : Int) + (-1)*↑x ≤ 0 then (↑x : Int) + (-1)*↑y else 0
   rw [Int.neg_mul, ← Int.sub_eq_add_neg, Int.one_mul]
   rw [Int.neg_mul, ← Int.sub_eq_add_neg, Int.one_mul]
   split
@@ -1708,6 +1788,7 @@ private theorem eq_neg_addConst_add (ctx : Context) (p : Poly)
   rw [Int.add_right_neg]
   simp
 
+@[expose]
 def dvd_le_tight_cert (d : Int) (p₁ p₂ p₃ : Poly) : Bool :=
   let b₁ := p₁.getConst
   let b₂ := p₂.getConst
@@ -1728,6 +1809,7 @@ theorem dvd_le_tight (ctx : Context) (d : Int) (p₁ p₂ p₃ : Poly)
   simp only [Poly.denote'_eq_denote]
   exact dvd_le_tight' hd
 
+@[expose]
 def dvd_neg_le_tight_cert (d : Int) (p₁ p₂ p₃ : Poly) : Bool :=
   let b₁ := p₁.getConst
   let b₂ := p₂.getConst
@@ -1737,7 +1819,7 @@ def dvd_neg_le_tight_cert (d : Int) (p₁ p₂ p₃ : Poly) : Bool :=
   d > 0 && (p₂ == p.addConst b₂ && p₃ == p.addConst (b₁ - d*((b₁ - b₂)/d)))
 
 theorem Poly.mul_minus_one_getConst_eq (p : Poly) : (p.mul (-1)).getConst = -p.getConst := by
-  simp [Poly.mul, Poly.getConst]
+  simp [Poly.mul]
   induction p <;> simp [Poly.mul', Poly.getConst, *]
 
 theorem dvd_neg_le_tight (ctx : Context) (d : Int) (p₁ p₂ p₃ : Poly)
@@ -1764,6 +1846,7 @@ theorem le_norm_expr (ctx : Context) (lhs rhs : Expr) (p : Poly)
     : norm_eq_cert lhs rhs p → lhs.denote ctx ≤ rhs.denote ctx → p.denote' ctx ≤ 0 := by
   intro h₁ h₂; rwa [norm_le ctx lhs rhs p h₁] at h₂
 
+@[expose]
 def not_le_norm_expr_cert (lhs rhs : Expr) (p : Poly) : Bool :=
   p == (((lhs.sub rhs).norm).mul (-1)).addConst 1
 
@@ -1796,6 +1879,7 @@ theorem of_not_dvd (a b : Int) : a != 0 → ¬ (a ∣ b) → b % a > 0 := by
   simp [h₁] at h₂
   assumption
 
+@[expose]
 def le_of_le_cert (p q : Poly) (k : Nat) : Bool :=
   q == p.addConst (- k)
 
@@ -1806,6 +1890,7 @@ theorem le_of_le (ctx : Context) (p q : Poly) (k : Nat)
   simp [Lean.Omega.Int.add_le_zero_iff_le_neg']
   exact Int.le_trans h (Int.ofNat_zero_le _)
 
+@[expose]
 def not_le_of_le_cert (p q : Poly) (k : Nat) : Bool :=
   q == (p.mul (-1)).addConst (1 + k)
 
@@ -1815,10 +1900,11 @@ theorem not_le_of_le (ctx : Context) (p q : Poly) (k : Nat)
   intro h
   apply Int.pos_of_neg_neg
   apply Int.lt_of_add_one_le
-  simp [Int.neg_add, Int.neg_sub]
+  simp [Int.neg_add]
   rw [← Int.add_assoc, ← Int.add_assoc, Int.add_neg_cancel_right, Lean.Omega.Int.add_le_zero_iff_le_neg']
   simp; exact Int.le_trans h (Int.ofNat_zero_le _)
 
+@[expose]
 def eq_def_cert (x : Var) (xPoly : Poly) (p : Poly) : Bool :=
   p == .add (-1) x xPoly
 
@@ -1827,6 +1913,7 @@ theorem eq_def (ctx : Context) (x : Var) (xPoly : Poly) (p : Poly)
   simp [eq_def_cert]; intro _ h; subst p; simp [h]
   rw [← Int.sub_eq_add_neg, Int.sub_self]
 
+@[expose]
 def eq_def'_cert (x : Var) (e : Expr) (p : Poly) : Bool :=
   p == .add (-1) x e.norm
 

src/Init/Data/Int/OfNat.lean

@@ -19,6 +19,7 @@ We use them to implement the arithmetic theories in `grind`
 
 abbrev Var := Nat
 abbrev Context := Lean.RArray Nat
+@[expose]
 def Var.denote (ctx : Context) (v : Var) : Nat :=
   ctx.get v
 
@@ -29,8 +30,10 @@ inductive Expr where
   | mul  (a b : Expr)
   | div  (a b : Expr)
   | mod  (a b : Expr)
+  | pow  (a : Expr) (k : Nat)
   deriving BEq
 
+@[expose]
 def Expr.denote (ctx : Context) : Expr → Nat
   | .num k    => k
   | .var v    => v.denote ctx
@@ -38,7 +41,9 @@ def Expr.denote (ctx : Context) : Expr → Nat
   | .mul a b  => Nat.mul (denote ctx a) (denote ctx b)
   | .div a b  => Nat.div (denote ctx a) (denote ctx b)
   | .mod a b  => Nat.mod (denote ctx a) (denote ctx b)
+  | .pow a k  => Nat.pow (denote ctx a) k
 
+@[expose]
 def Expr.denoteAsInt (ctx : Context) : Expr → Int
   | .num k    => Int.ofNat k
   | .var v    => Int.ofNat (v.denote ctx)
@@ -46,9 +51,10 @@ def Expr.denoteAsInt (ctx : Context) : Expr → Int
   | .mul a b  => Int.mul (denoteAsInt ctx a) (denoteAsInt ctx b)
   | .div a b  => Int.ediv (denoteAsInt ctx a) (denoteAsInt ctx b)
   | .mod a b  => Int.emod (denoteAsInt ctx a) (denoteAsInt ctx b)
+  | .pow a k  => Int.pow (denoteAsInt ctx a) k
 
 theorem Expr.denoteAsInt_eq (ctx : Context) (e : Expr) : e.denoteAsInt ctx = e.denote ctx := by
-  induction e <;> simp [denote, denoteAsInt, Int.natCast_ediv, *] <;> rfl
+  induction e <;> simp [denote, denoteAsInt, *] <;> rfl
 
 theorem Expr.eq_denoteAsInt (ctx : Context) (e : Expr) : e.denote ctx = e.denoteAsInt ctx := by
   apply Eq.symm; apply denoteAsInt_eq

src/Init/Data/Int/Order.lean

@@ -448,7 +448,7 @@ protected theorem le_max_left (a b : Int) : a ≤ max a b := by rw [Int.max_def]
 protected theorem le_max_right (a b : Int) : b ≤ max a b := Int.max_comm .. ▸ Int.le_max_left ..
 
 protected theorem max_eq_right {a b : Int} (h : a ≤ b) : max a b = b := by
-  simp [Int.max_def, h, Int.not_lt.2 h]
+  simp [Int.max_def, h]
 
 protected theorem max_eq_left {a b : Int} (h : b ≤ a) : max a b = a := by
   rw [← Int.max_comm b a]; exact Int.max_eq_right h

src/Init/Data/Int/Pow.lean

@@ -19,6 +19,13 @@ protected theorem pow_succ (b : Int) (e : Nat) : b ^ (e+1) = (b ^ e) * b := rfl
 protected theorem pow_succ' (b : Int) (e : Nat) : b ^ (e+1) = b * (b ^ e) := by
   rw [Int.mul_comm, Int.pow_succ]
 
+protected theorem zero_pow {n : Nat} (h : n ≠ 0) : (0 : Int) ^ n = 0 := by
+  match n, h with
+  | n + 1, _ => simp [Int.pow_succ]
+
+protected theorem one_pow {n : Nat} : (1 : Int) ^ n = 1 := by
+  induction n with simp_all [Int.pow_succ]
+
 protected theorem pow_pos {n : Int} {m : Nat} : 0 < n → 0 < n ^ m := by
   induction m with
   | zero => simp

src/Init/Data/Iterators.lean

@@ -0,0 +1,21 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Paul Reichert
+-/
+module
+
+prelude
+import Init.Data.Iterators.Basic
+import Init.Data.Iterators.PostconditionMonad
+import Init.Data.Iterators.Consumers
+import Init.Data.Iterators.Combinators
+import Init.Data.Iterators.Lemmas
+import Init.Data.Iterators.ToIterator
+import Init.Data.Iterators.Internal
+
+/-!
+# Iterators
+
+See `Std.Data.Iterators` for an overview over the iterator API.
+-/

src/Init/Data/Iterators/Basic.lean

@@ -3,9 +3,12 @@ Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Paul Reichert
 -/
+module
+
 prelude
 import Init.Core
 import Init.Classical
+import Init.Ext
 import Init.NotationExtra
 import Init.TacticsExtra
 
@@ -30,7 +33,7 @@ See `Std.Data.Iterators.Producers` for ways to iterate over common data structur
 By convention, the monadic iterator associated with an object can be obtained via dot notation.
 For example, `List.iterM IO` creates an iterator over a list in the monad `IO`.
 
-See `Std.Data.Iterators.Consumers` for ways to use an iterator. For example, `it.toList` will
+See `Init.Data.Iterators.Consumers` for ways to use an iterator. For example, `it.toList` will
 convert a provably finite iterator `it` into a list and `it.allowNontermination.toList` will
 do so even if finiteness cannot be proved. It is also always possible to manually iterate using
 `it.step`, relying on the termination measures `it.finitelyManySteps` and `it.finitelyManySkips`.
@@ -58,6 +61,7 @@ def x := [1, 2, 3].iterM IO
 def x := ([1, 2, 3].iterM IO : IterM IO Nat)
 ```
 -/
+@[ext]
 structure IterM {α : Type w} (m : Type w → Type w') (β : Type w) where
   /-- Internal implementation detail of the iterator. -/
   internalState : α
@@ -73,7 +77,7 @@ See `Std.Data.Iterators.Producers` for ways to iterate over common data structur
 By convention, the monadic iterator associated with an object can be obtained via dot notation.
 For example, `List.iterM IO` creates an iterator over a list in the monad `IO`.
 
-See `Std.Data.Iterators.Consumers` for ways to use an iterator. For example, `it.toList` will
+See `Init.Data.Iterators.Consumers` for ways to use an iterator. For example, `it.toList` will
 convert a provably finite iterator `it` into a list and `it.allowNontermination.toList` will
 do so even if finiteness cannot be proved. It is also always possible to manually iterate using
 `it.step`, relying on the termination measures `it.finitelyManySteps` and `it.finitelyManySkips`.
@@ -109,12 +113,14 @@ structure Iter {α : Type w} (β : Type w) where
 Converts a pure iterator (`Iter β`) into a monadic iterator (`IterM Id β`) in the
 identity monad `Id`.
 -/
+@[expose]
 def Iter.toIterM {α : Type w} {β : Type w} (it : Iter (α := α) β) : IterM (α := α) Id β :=
   ⟨it.internalState⟩
 
 /--
 Converts a monadic iterator (`IterM Id β`) over `Id` into a pure iterator (`Iter β`).
 -/
+@[expose]
 def IterM.toIter {α : Type w} {β : Type w} (it : IterM (α := α) Id β) : Iter (α := α) β :=
   ⟨it.internalState⟩
 
@@ -168,6 +174,7 @@ inductive IterStep (α β) where
 Returns the succeeding iterator stored in an iterator step or `none` if the step is `.done`
 and the iterator has finished.
 -/
+@[expose]
 def IterStep.successor : IterStep α β → Option α
   | .yield it _ => some it
   | .skip it => some it
@@ -177,7 +184,7 @@ def IterStep.successor : IterStep α β → Option α
 If present, applies `f` to the iterator of an `IterStep` and replaces the iterator
 with the result of the application of `f`.
 -/
-@[always_inline, inline]
+@[always_inline, inline, expose]
 def IterStep.mapIterator {α' : Type u'} (f : α → α') : IterStep α β → IterStep α' β
   | .yield it out => .yield (f it) out
   | .skip it => .skip (f it)
@@ -204,6 +211,12 @@ theorem IterStep.mapIterator_mapIterator {α' : Type u'} {α'' : Type u''}
     (step.mapIterator f).mapIterator g = step.mapIterator (g ∘ f) := by
   cases step <;> rfl
 
+theorem IterStep.mapIterator_comp {α' : Type u'} {α'' : Type u''}
+    {f : α → α'} {g : α' → α''} :
+    IterStep.mapIterator (β := β) (g ∘ f) = mapIterator g ∘ mapIterator f := by
+  apply funext
+  exact fun _ => mapIterator_mapIterator.symm
+
 @[simp]
 theorem IterStep.mapIterator_id {step : IterStep α β} :
     step.mapIterator id = step := by
@@ -216,12 +229,13 @@ of another state. Having this proof bundled up with the step is important for te
 
 See `IterM.Step` and `Iter.Step` for the concrete choice of the plausibility predicate.
 -/
+@[expose]
 def PlausibleIterStep (IsPlausibleStep : IterStep α β → Prop) := Subtype IsPlausibleStep
 
 /--
 Match pattern for the `yield` case. See also `IterStep.yield`.
 -/
-@[match_pattern, simp]
+@[match_pattern, simp, expose]
 def PlausibleIterStep.yield {IsPlausibleStep : IterStep α β → Prop}
     (it' : α) (out : β) (h : IsPlausibleStep (.yield it' out)) :
     PlausibleIterStep IsPlausibleStep :=
@@ -230,7 +244,7 @@ def PlausibleIterStep.yield {IsPlausibleStep : IterStep α β → Prop}
 /--
 Match pattern for the `skip` case. See also `IterStep.skip`.
 -/
-@[match_pattern, simp]
+@[match_pattern, simp, expose]
 def PlausibleIterStep.skip {IsPlausibleStep : IterStep α β → Prop}
     (it' : α) (h : IsPlausibleStep (.skip it')) : PlausibleIterStep IsPlausibleStep :=
   ⟨.skip it', h⟩
@@ -238,7 +252,7 @@ def PlausibleIterStep.skip {IsPlausibleStep : IterStep α β → Prop}
 /--
 Match pattern for the `done` case. See also `IterStep.done`.
 -/
-@[match_pattern, simp]
+@[match_pattern, simp, expose]
 def PlausibleIterStep.done {IsPlausibleStep : IterStep α β → Prop}
     (h : IsPlausibleStep .done) : PlausibleIterStep IsPlausibleStep :=
   ⟨.done, h⟩
@@ -275,7 +289,7 @@ section Monadic
 /--
 Converts wraps the state of an iterator into an `IterM` object.
 -/
-@[always_inline, inline]
+@[always_inline, inline, expose]
 def toIterM {α : Type w} (it : α) (m : Type w → Type w') (β : Type w) :
     IterM (α := α) m β :=
   ⟨it⟩
@@ -294,6 +308,7 @@ theorem internalState_toIterM {α m β} (it : α) :
 Asserts that certain step is plausibly the successor of a given iterator. What "plausible" means
 is up to the `Iterator` instance but it should be strong enough to allow termination proofs.
 -/
+@[expose]
 abbrev IterM.IsPlausibleStep {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β] :
     IterM (α := α) m β → IterStep (IterM (α := α) m β) β → Prop :=
   Iterator.IsPlausibleStep (α := α) (m := m)
@@ -302,6 +317,7 @@ abbrev IterM.IsPlausibleStep {α : Type w} {m : Type w → Type w'} {β : Type w
 The type of the step object returned by `IterM.step`, containing an `IterStep`
 and a proof that this is a plausible step for the given iterator.
 -/
+@[expose]
 abbrev IterM.Step {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     (it : IterM (α := α) m β) :=
   PlausibleIterStep it.IsPlausibleStep
@@ -310,6 +326,7 @@ abbrev IterM.Step {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator
 Asserts that a certain output value could plausibly be emitted by the given iterator in its next
 step.
 -/
+@[expose]
 def IterM.IsPlausibleOutput {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     (it : IterM (α := α) m β) (out : β) : Prop :=
   ∃ it', it.IsPlausibleStep (.yield it' out)
@@ -318,6 +335,7 @@ def IterM.IsPlausibleOutput {α : Type w} {m : Type w → Type w'} {β : Type w}
 Asserts that a certain iterator `it'` could plausibly be the directly succeeding iterator of another
 given iterator `it`.
 -/
+@[expose]
 def IterM.IsPlausibleSuccessorOf {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     (it' it : IterM (α := α) m β) : Prop :=
   ∃ step, step.successor = some it' ∧ it.IsPlausibleStep step
@@ -326,6 +344,7 @@ def IterM.IsPlausibleSuccessorOf {α : Type w} {m : Type w → Type w'} {β : Ty
 Asserts that a certain iterator `it'` could plausibly be the directly succeeding iterator of another
 given iterator `it` while no value is emitted (see `IterStep.skip`).
 -/
+@[expose]
 def IterM.IsPlausibleSkipSuccessorOf {α : Type w} {m : Type w → Type w'} {β : Type w}
     [Iterator α m β] (it' it : IterM (α := α) m β) : Prop :=
   it.IsPlausibleStep (.skip it')
@@ -335,7 +354,7 @@ Makes a single step with the given iterator `it`, potentially emitting a value a
 succeeding iterator. If this function is used recursively, termination can sometimes be proved with
 the termination measures `it.finitelyManySteps` and `it.finitelyManySkips`.
 -/
-@[always_inline, inline]
+@[always_inline, inline, expose]
 def IterM.step {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     (it : IterM (α := α) m β) : m it.Step :=
   Iterator.step it
@@ -348,14 +367,59 @@ section Pure
 Asserts that certain step is plausibly the successor of a given iterator. What "plausible" means
 is up to the `Iterator` instance but it should be strong enough to allow termination proofs.
 -/
+@[expose]
 def Iter.IsPlausibleStep {α : Type w} {β : Type w} [Iterator α Id β]
     (it : Iter (α := α) β) (step : IterStep (Iter (α := α) β) β) : Prop :=
   it.toIterM.IsPlausibleStep (step.mapIterator Iter.toIterM)
 
+/--
+Asserts that a certain iterator `it` could plausibly yield the value `out` after an arbitrary
+number of steps.
+-/
+inductive IterM.IsPlausibleIndirectOutput {α β : Type w} {m : Type w → Type w'} [Iterator α m β]
+    : IterM (α := α) m β → β → Prop where
+  | direct {it : IterM (α := α) m β} {out : β} : it.IsPlausibleOutput out →
+      it.IsPlausibleIndirectOutput out
+  | indirect {it it' : IterM (α := α) m β} {out : β} : it'.IsPlausibleSuccessorOf it →
+      it'.IsPlausibleIndirectOutput out → it.IsPlausibleIndirectOutput out
+
+/--
+Asserts that an iterator `it'` could plausibly produce `it'` as a successor iterator after
+finitely many steps. This relation is reflexive.
+-/
+inductive IterM.IsPlausibleIndirectSuccessorOf {α β : Type w} {m : Type w → Type w'}
+    [Iterator α m β] : IterM (α := α) m β → IterM (α := α) m β → Prop where
+  | refl (it : IterM (α := α) m β) : it.IsPlausibleIndirectSuccessorOf it
+  | cons_right {it'' it' it : IterM (α := α) m β} (h' : it''.IsPlausibleIndirectSuccessorOf it')
+      (h : it'.IsPlausibleSuccessorOf it) : it''.IsPlausibleIndirectSuccessorOf it
+
+theorem IterM.IsPlausibleIndirectSuccessorOf.trans {α β : Type w} {m : Type w → Type w'}
+    [Iterator α m β] {it'' it' it : IterM (α := α) m β}
+    (h' : it''.IsPlausibleIndirectSuccessorOf it') (h : it'.IsPlausibleIndirectSuccessorOf it) :
+    it''.IsPlausibleIndirectSuccessorOf it := by
+  induction h
+  case refl => exact h'
+  case cons_right ih => exact IsPlausibleIndirectSuccessorOf.cons_right ih ‹_›
+
+theorem IterM.IsPlausibleIndirectSuccessorOf.single {α β : Type w} {m : Type w → Type w'}
+    [Iterator α m β] {it' it : IterM (α := α) m β}
+    (h : it'.IsPlausibleSuccessorOf it) :
+    it'.IsPlausibleIndirectSuccessorOf it :=
+  .cons_right (.refl _) h
+
+theorem IterM.IsPlausibleIndirectOutput.trans {α β : Type w} {m : Type w → Type w'}
+    [Iterator α m β]
+    {it' it : IterM (α := α) m β} {out : β} (h : it'.IsPlausibleIndirectSuccessorOf it)
+    (h' : it'.IsPlausibleIndirectOutput out) : it.IsPlausibleIndirectOutput out := by
+  induction h
+  case refl => exact h'
+  case cons_right ih => exact IsPlausibleIndirectOutput.indirect ‹_› ih
+
 /--
 The type of the step object returned by `Iter.step`, containing an `IterStep`
 and a proof that this is a plausible step for the given iterator.
 -/
+@[expose]
 def Iter.Step {α : Type w} {β : Type w} [Iterator α Id β] (it : Iter (α := α) β) :=
   PlausibleIterStep (Iter.IsPlausibleStep it)
 
@@ -370,7 +434,7 @@ def Iter.Step.toMonadic {α : Type w} {β : Type w} [Iterator α Id β] {it : It
 /--
 Converts an `IterM.Step` into an `Iter.Step`.
 -/
-@[always_inline, inline]
+@[always_inline, inline, expose]
 def IterM.Step.toPure {α : Type w} {β : Type w} [Iterator α Id β] {it : IterM (α := α) Id β}
     (step : it.Step) : it.toIter.Step :=
   ⟨step.val.mapIterator IterM.toIter, (by simp [Iter.IsPlausibleStep, step.property])⟩
@@ -394,18 +458,113 @@ theorem IterM.Step.toPure_done {α β : Type w} [Iterator α Id β] {it : IterM
 Asserts that a certain output value could plausibly be emitted by the given iterator in its next
 step.
 -/
+@[expose]
 def Iter.IsPlausibleOutput {α : Type w} {β : Type w} [Iterator α Id β]
     (it : Iter (α := α) β) (out : β) : Prop :=
   it.toIterM.IsPlausibleOutput out
 
+theorem Iter.isPlausibleOutput_iff_exists {α : Type w} {β : Type w} [Iterator α Id β]
+    {it : Iter (α := α) β} {out : β} :
+    it.IsPlausibleOutput out ↔ ∃ it', it.IsPlausibleStep (.yield it' out) := by
+  simp only [IsPlausibleOutput, IterM.IsPlausibleOutput]
+  constructor
+  · rintro ⟨it', h⟩
+    exact ⟨it'.toIter, h⟩
+  · rintro ⟨it', h⟩
+    exact ⟨it'.toIterM, h⟩
+
 /--
 Asserts that a certain iterator `it'` could plausibly be the directly succeeding iterator of another
 given iterator `it`.
 -/
+@[expose]
 def Iter.IsPlausibleSuccessorOf {α : Type w} {β : Type w} [Iterator α Id β]
     (it' it : Iter (α := α) β) : Prop :=
   it'.toIterM.IsPlausibleSuccessorOf it.toIterM
 
+theorem Iter.isPlausibleSuccessorOf_iff_exists {α : Type w} {β : Type w} [Iterator α Id β]
+    {it' it : Iter (α := α) β} :
+    it'.IsPlausibleSuccessorOf it ↔ ∃ step, step.successor = some it' ∧ it.IsPlausibleStep step := by
+  simp only [IsPlausibleSuccessorOf, IterM.IsPlausibleSuccessorOf]
+  constructor
+  · rintro ⟨step, h₁, h₂⟩
+    exact ⟨step.mapIterator IterM.toIter,
+      by cases step <;> simp_all [IterStep.successor, Iter.IsPlausibleStep]⟩
+  · rintro ⟨step, h₁, h₂⟩
+    exact ⟨step.mapIterator Iter.toIterM,
+      by cases step <;> simp_all [IterStep.successor, Iter.IsPlausibleStep]⟩
+
+/--
+Asserts that a certain iterator `it` could plausibly yield the value `out` after an arbitrary
+number of steps.
+-/
+inductive Iter.IsPlausibleIndirectOutput {α β : Type w} [Iterator α Id β] :
+    Iter (α := α) β → β → Prop where
+  | direct {it : Iter (α := α) β} {out : β} : it.IsPlausibleOutput out →
+      it.IsPlausibleIndirectOutput out
+  | indirect {it it' : Iter (α := α) β} {out : β} : it'.IsPlausibleSuccessorOf it →
+      it'.IsPlausibleIndirectOutput out → it.IsPlausibleIndirectOutput out
+
+theorem Iter.isPlausibleIndirectOutput_iff_isPlausibleIndirectOutput_toIterM {α β : Type w}
+    [Iterator α Id β] {it : Iter (α := α) β} {out : β} :
+    it.IsPlausibleIndirectOutput out ↔ it.toIterM.IsPlausibleIndirectOutput out := by
+  constructor
+  · intro h
+    induction h with
+    | direct h =>
+      exact .direct h
+    | indirect h _ ih =>
+      exact .indirect h ih
+  · intro h
+    rw [← Iter.toIter_toIterM (it := it)]
+    generalize it.toIterM = it at ⊢ h
+    induction h with
+    | direct h =>
+      exact .direct h
+    | indirect h h' ih =>
+      rename_i it it' out
+      replace h : it'.toIter.IsPlausibleSuccessorOf it.toIter := h
+      exact .indirect (α := α) h ih
+
+/--
+Asserts that an iterator `it'` could plausibly produce `it'` as a successor iterator after
+finitely many steps. This relation is reflexive.
+-/
+inductive Iter.IsPlausibleIndirectSuccessorOf {α : Type w} {β : Type w} [Iterator α Id β] :
+    Iter (α := α) β → Iter (α := α) β → Prop where
+  | refl (it : Iter (α := α) β) : IsPlausibleIndirectSuccessorOf it it
+  | cons_right {it'' it' it : Iter (α := α) β} (h' : it''.IsPlausibleIndirectSuccessorOf it')
+      (h : it'.IsPlausibleSuccessorOf it) : it''.IsPlausibleIndirectSuccessorOf it
+
+theorem Iter.isPlausibleIndirectSuccessor_iff_isPlausibleIndirectSuccessor_toIterM {α β : Type w}
+    [Iterator α Id β] {it' it : Iter (α := α) β} :
+    it'.IsPlausibleIndirectSuccessorOf it ↔ it'.toIterM.IsPlausibleIndirectSuccessorOf it.toIterM := by
+  constructor
+  · intro h
+    induction h with
+    | refl => exact .refl _
+    | cons_right _ h ih => exact .cons_right ih h
+  · intro h
+    rw [← Iter.toIter_toIterM (it := it), ← Iter.toIter_toIterM (it := it')]
+    generalize it.toIterM = it at ⊢ h
+    induction h with
+    | refl => exact .refl _
+    | cons_right _ h ih => exact .cons_right ih h
+
+theorem Iter.IsPlausibleIndirectSuccessorOf.trans {α : Type w} {β : Type w} [Iterator α Id β]
+    {it'' it' it : Iter (α := α) β} (h' : it''.IsPlausibleIndirectSuccessorOf it')
+    (h : it'.IsPlausibleIndirectSuccessorOf it) : it''.IsPlausibleIndirectSuccessorOf it := by
+  induction h
+  case refl => exact h'
+  case cons_right ih => exact IsPlausibleIndirectSuccessorOf.cons_right ih ‹_›
+
+theorem Iter.IsPlausibleIndirectOutput.trans {α : Type w} {β : Type w} [Iterator α Id β]
+    {it' it : Iter (α := α) β} {out : β} (h : it'.IsPlausibleIndirectSuccessorOf it)
+    (h' : it'.IsPlausibleIndirectOutput out) : it.IsPlausibleIndirectOutput out := by
+  induction h
+  case refl => exact h'
+  case cons_right ih => exact IsPlausibleIndirectOutput.indirect ‹_› ih
+
 /--
 Asserts that a certain iterator `it'` could plausibly be the directly succeeding iterator of another
 given iterator `it` while no value is emitted (see `IterStep.skip`).
@@ -419,7 +578,7 @@ Makes a single step with the given iterator `it`, potentially emitting a value a
 succeeding iterator. If this function is used recursively, termination can sometimes be proved with
 the termination measures `it.finitelyManySteps` and `it.finitelyManySkips`.
 -/
-@[always_inline, inline]
+@[always_inline, inline, expose]
 def Iter.step {α β : Type w} [Iterator α Id β] (it : Iter (α := α) β) : it.Step :=
   it.toIterM.step.run.toPure
 
@@ -448,6 +607,7 @@ structure IterM.TerminationMeasures.Finite
 The relation of plausible successors on `IterM.TerminationMeasures.Finite`. It is well-founded
 if there is a `Finite` instance.
 -/
+@[expose]
 def IterM.TerminationMeasures.Finite.Rel
     {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β] :
     TerminationMeasures.Finite α m → TerminationMeasures.Finite α m → Prop :=
@@ -456,12 +616,13 @@ def IterM.TerminationMeasures.Finite.Rel
 instance {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     [Finite α m] : WellFoundedRelation (IterM.TerminationMeasures.Finite α m) where
   rel := IterM.TerminationMeasures.Finite.Rel
-  wf := (InvImage.wf _ Finite.wf).transGen
+  wf := by exact (InvImage.wf _ Finite.wf).transGen
 
 /--
 Termination measure to be used in well-founded recursive functions recursing over a finite iterator
 (see also `Finite`).
 -/
+@[expose]
 def IterM.finitelyManySteps {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     [Finite α m] (it : IterM (α := α) m β) : IterM.TerminationMeasures.Finite α m :=
   ⟨it⟩
@@ -486,9 +647,10 @@ theorem IterM.TerminationMeasures.Finite.rel_of_skip
 macro_rules | `(tactic| decreasing_trivial) => `(tactic|
   first
   | exact IterM.TerminationMeasures.Finite.rel_of_yield ‹_›
-  | exact IterM.TerminationMeasures.Finite.rel_of_skip ‹_›)
+  | exact IterM.TerminationMeasures.Finite.rel_of_skip ‹_›
+  | fail)
 
-@[inherit_doc IterM.finitelyManySteps]
+@[inherit_doc IterM.finitelyManySteps, expose]
 def Iter.finitelyManySteps {α : Type w} {β : Type w} [Iterator α Id β] [Finite α Id]
     (it : Iter (α := α) β) : IterM.TerminationMeasures.Finite α Id :=
   it.toIterM.finitelyManySteps
@@ -513,7 +675,8 @@ theorem Iter.TerminationMeasures.Finite.rel_of_skip
 macro_rules | `(tactic| decreasing_trivial) => `(tactic|
   first
   | exact Iter.TerminationMeasures.Finite.rel_of_yield ‹_›
-  | exact Iter.TerminationMeasures.Finite.rel_of_skip ‹_›)
+  | exact Iter.TerminationMeasures.Finite.rel_of_skip ‹_›
+  | fail)
 
 theorem IterM.isPlausibleSuccessorOf_of_yield
     {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
@@ -553,6 +716,7 @@ structure IterM.TerminationMeasures.Productive
 The relation of plausible successors while skipping on `IterM.TerminationMeasures.Productive`.
 It is well-founded if there is a `Productive` instance.
 -/
+@[expose]
 def IterM.TerminationMeasures.Productive.Rel
     {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β] :
     TerminationMeasures.Productive α m → TerminationMeasures.Productive α m → Prop :=
@@ -561,12 +725,13 @@ def IterM.TerminationMeasures.Productive.Rel
 instance {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     [Productive α m] : WellFoundedRelation (IterM.TerminationMeasures.Productive α m) where
   rel := IterM.TerminationMeasures.Productive.Rel
-  wf := (InvImage.wf _ Productive.wf).transGen
+  wf := by exact (InvImage.wf _ Productive.wf).transGen
 
 /--
 Termination measure to be used in well-founded recursive functions recursing over a productive
 iterator (see also `Productive`).
 -/
+@[expose]
 def IterM.finitelyManySkips {α : Type w} {m : Type w → Type w'} {β : Type w} [Iterator α m β]
     [Productive α m] (it : IterM (α := α) m β) : IterM.TerminationMeasures.Productive α m :=
   ⟨it⟩
@@ -582,9 +747,11 @@ theorem IterM.TerminationMeasures.Productive.rel_of_skip
   .single h
 
 macro_rules | `(tactic| decreasing_trivial) => `(tactic|
-  exact IterM.TerminationMeasures.Productive.rel_of_skip ‹_›)
+  first
+    | exact IterM.TerminationMeasures.Productive.rel_of_skip ‹_›
+    | fail)
 
-@[inherit_doc IterM.finitelyManySkips]
+@[inherit_doc IterM.finitelyManySkips, expose]
 def Iter.finitelyManySkips {α : Type w} {β : Type w} [Iterator α Id β] [Productive α Id]
     (it : Iter (α := α) β) : IterM.TerminationMeasures.Productive α Id :=
   it.toIterM.finitelyManySkips
@@ -600,7 +767,9 @@ theorem Iter.TerminationMeasures.Productive.rel_of_skip
   IterM.TerminationMeasures.Productive.rel_of_skip h
 
 macro_rules | `(tactic| decreasing_trivial) => `(tactic|
-  exact Iter.TerminationMeasures.Productive.rel_of_skip ‹_›)
+  first
+    | exact Iter.TerminationMeasures.Productive.rel_of_skip ‹_›
+    | fail)
 
 instance [Iterator α m β] [Finite α m] : Productive α m where
   wf := by
@@ -611,6 +780,21 @@ instance [Iterator α m β] [Finite α m] : Productive α m where
 
 end Productive
 
+/--
+This typeclass characterizes iterators that have deterministic return values. This typeclass does
+*not* guarantee that there are no monadic side effects such as exceptions.
+
+General monadic iterators can be nondeterministic, so that `it.IsPlausibleStep step` will be true
+for no or more than one choice of `step`. This typeclass ensures that there is exactly one such
+choice.
+
+This is an experimental instance and it should not be explicitly used downstream of the standard
+library.
+-/
+class LawfulDeterministicIterator (α : Type w) (m : Type w → Type w') [Iterator α m β]
+    where
+  isPlausibleStep_eq_eq : ∀ it : IterM (α := α) m β, ∃ step, it.IsPlausibleStep = (· = step)
+
 end Iterators
 
 export Iterators (Iter IterM)

src/Init/Data/Iterators/Combinators.lean

@@ -0,0 +1,11 @@
+/-
+Copyright (c) 2025 Lean FRO, LLC. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+Authors: Paul Reichert
+-/
+module
+
+prelude
+import Init.Data.Iterators.Combinators.Monadic
+import Init.Data.Iterators.Combinators.FilterMap
+import Init.Data.Iterators.Combinators.ULift