fixes

.github/ISSUE_TEMPLATE/bug_report.md

@@ -39,7 +39,7 @@ Please put an X between the brackets as you perform the following steps:
 
 ### Versions
 
-[Output of `#version` or `#eval Lean.versionString`]
+[Output of `#eval Lean.versionString`]
 [OS version, if not using live.lean-lang.org.]
 
 ### Additional Information

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,10 +5,6 @@
 * Include the link to your `RFC` or `bug` issue in the description.
 * If the issue does not already have approval from a developer, submit the PR as draft.
 * The PR title/description will become the commit message. Keep it up-to-date as the PR evolves.
-* For `feat/fix` PRs, the first paragraph starting with "This PR" must be present and will become a
-  changelog entry unless the PR is labeled with `no-changelog`. If the PR does not have this label,
-  it must instead be categorized with one of the `changelog-*` labels (which will be done by a
-  reviewer for external PRs).
 * A toolchain of the form `leanprover/lean4-pr-releases:pr-release-NNNN` for Linux and M-series Macs will be generated upon build. To generate binaries for Windows and Intel-based Macs as well, write a comment containing `release-ci` on its own line.
 * If you rebase your PR onto `nightly-with-mathlib` then CI will test Mathlib against your PR.
 * You can manage the `awaiting-review`, `awaiting-author`, and `WIP` labels yourself, by writing a comment containing one of these labels on its own line.
@@ -16,6 +12,4 @@
 
 ---
 
-This PR <short changelog summary for feat/fix, see above>.
-
-Closes <`RFC` or `bug` issue number fixed by this PR, if any>
+Closes #0000 (`RFC` or `bug` issue number fixed by this PR, if any)

.github/dependabot.yml

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

.github/workflows/actionlint.yml

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

.github/workflows/check-prelude.yml

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

.github/workflows/ci.yml

@@ -217,7 +217,7 @@ jobs:
                 "release": true,
                 "check-level": 2,
                 "shell": "msys2 {0}",
-                "CMAKE_OPTIONS": "-G \"Unix Makefiles\"",
+                "CMAKE_OPTIONS": "-G \"Unix Makefiles\" -DUSE_GMP=OFF",
                 // for reasons unknown, interactivetests are flaky on Windows
                 "CTEST_OPTIONS": "--repeat until-pass:2",
                 "llvm-url": "https://github.com/leanprover/lean-llvm/releases/download/15.0.1/lean-llvm-x86_64-w64-windows-gnu.tar.zst",
@@ -227,7 +227,7 @@ jobs:
               {
                 "name": "Linux aarch64",
                 "os": "nscloud-ubuntu-22.04-arm64-4x8",
-                "CMAKE_OPTIONS": "-DLEAN_INSTALL_SUFFIX=-linux_aarch64",
+                "CMAKE_OPTIONS": "-DUSE_GMP=OFF -DLEAN_INSTALL_SUFFIX=-linux_aarch64",
                 "release": true,
                 "check-level": 2,
                 "shell": "nix develop .#oldGlibcAArch -c bash -euxo pipefail {0}",
@@ -318,7 +318,7 @@ jobs:
         if: github.event_name == 'pull_request'
       # (needs to be after "Checkout" so files don't get overridden)
       - name: Setup emsdk
-        uses: mymindstorm/setup-emsdk@v14
+        uses: mymindstorm/setup-emsdk@v12
         with:
           version: 3.1.44
           actions-cache-folder: emsdk
@@ -492,7 +492,7 @@ jobs:
         with:
           path: artifacts
       - name: Release
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v1
         with:
           files: artifacts/*/*
           fail_on_unmatched_files: true
@@ -536,7 +536,7 @@ jobs:
           echo -e "\n*Full commit log*\n" >> diff.md
           git log --oneline "$last_tag"..HEAD | sed 's/^/* /' >> diff.md
       - name: Release Nightly
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v1
         with:
           body_path: diff.md
           prerelease: true

.github/workflows/nix-ci.yml

@@ -96,7 +96,7 @@ jobs:
           nix build $NIX_BUILD_ARGS .#cacheRoots -o push-build
       - name: Test
         run: |
-          nix build --keep-failed $NIX_BUILD_ARGS .#test -o push-test || (ln -s /tmp/nix-build-*/build/source/src/build ./push-test; false)
+          nix build --keep-failed $NIX_BUILD_ARGS .#test -o push-test || (ln -s /tmp/nix-build-*/source/src/build/ ./push-test; false)
       - name: Test Summary
         uses: test-summary/action@v2
         with:
@@ -110,6 +110,14 @@ jobs:
           # https://github.com/netlify/cli/issues/1809
           cp -r --dereference ./result ./dist
         if: matrix.name == 'Nix Linux'
+      - name: Check manual for broken links
+        id: lychee
+        uses: lycheeverse/lychee-action@v1.9.0
+        with:
+          fail: false  # report errors but do not block CI on temporary failures
+          # gmplib.org consistently times out from GH actions
+          # the GitHub token is to avoid rate limiting
+          args: --base './dist' --no-progress --github-token ${{ secrets.GITHUB_TOKEN }} --exclude 'gmplib.org' './dist/**/*.html'
       - name: Rebuild Nix Store Cache
         run: |
           rm -rf nix-store-cache || true
@@ -121,7 +129,7 @@ jobs:
           python3 -c 'import base64; print("alias="+base64.urlsafe_b64encode(bytes.fromhex("${{github.sha}}")).decode("utf-8").rstrip("="))' >> "$GITHUB_OUTPUT"
           echo "message=`git log -1 --pretty=format:"%s"`" >> "$GITHUB_OUTPUT"
       - name: Publish manual to Netlify
-        uses: nwtgck/actions-netlify@v3.0
+        uses: nwtgck/actions-netlify@v2.0
         id: publish-manual
         with:
           publish-dir: ./dist

.github/workflows/pr-body.yml

@@ -1,23 +0,0 @@
-name: Check PR body for changelog convention
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened, edited, labeled, converted_to_draft, ready_for_review]
-
-jobs:
-  check-pr-body:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Check PR body
-        uses: actions/github-script@v7
-        with:
-          script: |
-            const { title, body, labels, draft } = context.payload.pull_request;
-            if (!draft && /^(feat|fix):/.test(title) && !labels.some(label => label.name == "changelog-no")) {
-              if (!labels.some(label => label.name.startsWith("changelog-"))) {
-                core.setFailed('feat/fix PR must have a `changelog-*` label');
-              }
-              if (!/^This PR [^<]/.test(body)) {
-                core.setFailed('feat/fix PR must have changelog summary starting with "This PR ..." as first line.');
-              }
-            }

.github/workflows/pr-release.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Download artifact from the previous workflow.
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
         id: download-artifact
-        uses: dawidd6/action-download-artifact@v6 # https://github.com/marketplace/actions/download-workflow-artifact
+        uses: dawidd6/action-download-artifact@v2 # https://github.com/marketplace/actions/download-workflow-artifact
         with:
           run_id: ${{ github.event.workflow_run.id }}
           path: artifacts
@@ -60,7 +60,7 @@ jobs:
           GH_TOKEN: ${{ secrets.PR_RELEASES_TOKEN }}
       - name: Release
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: softprops/action-gh-release@v2
+        uses: softprops/action-gh-release@v1
         with:
           name: Release for PR ${{ steps.workflow-info.outputs.pullRequestNumber }}
           # There are coredumps files here as well, but all in deeper subdirectories.
@@ -75,7 +75,7 @@ jobs:
 
       - name: Report release status
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: actions/github-script@v7
+        uses: actions/github-script@v6
         with:
           script: |
             await github.rest.repos.createCommitStatus({
@@ -111,7 +111,7 @@ jobs:
 
       - name: 'Setup jq'
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' }}
-        uses: dcarbone/install-jq-action@v2.1.0
+        uses: dcarbone/install-jq-action@v1.0.1
 
       # Check that the most recently nightly coincides with 'git merge-base HEAD master'
       - name: Check merge-base and nightly-testing-YYYY-MM-DD
@@ -208,7 +208,7 @@ jobs:
 
       - name: Report mathlib base
         if: ${{ steps.workflow-info.outputs.pullRequestNumber != '' && steps.ready.outputs.mathlib_ready == 'true' }}
-        uses: actions/github-script@v7
+        uses: actions/github-script@v6
         with:
           script: |
             const description =

.github/workflows/stale.yml

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

CODEOWNERS

@@ -4,14 +4,14 @@
 # Listed persons will automatically be asked by GitHub to review a PR touching these paths.
 # If multiple names are listed, a review by any of them is considered sufficient by default.
 
-/.github/ @Kha @kim-em
-/RELEASES.md @kim-em
+/.github/ @Kha @semorrison
+/RELEASES.md @semorrison
 /src/kernel/ @leodemoura
 /src/lake/ @tydeu
 /src/Lean/Compiler/ @leodemoura
 /src/Lean/Data/Lsp/ @mhuisi
-/src/Lean/Elab/Deriving/ @kim-em
-/src/Lean/Elab/Tactic/ @kim-em
+/src/Lean/Elab/Deriving/ @semorrison
+/src/Lean/Elab/Tactic/ @semorrison
 /src/Lean/Language/ @Kha
 /src/Lean/Meta/Tactic/ @leodemoura
 /src/Lean/Parser/ @Kha
@@ -19,7 +19,7 @@
 /src/Lean/PrettyPrinter/Delaborator/ @kmill
 /src/Lean/Server/ @mhuisi
 /src/Lean/Widget/ @Vtec234
-/src/Init/Data/ @kim-em
+/src/Init/Data/ @semorrison
 /src/Init/Data/Array/Lemmas.lean @digama0
 /src/Init/Data/List/Lemmas.lean @digama0
 /src/Init/Data/List/BasicAux.lean @digama0
@@ -45,4 +45,3 @@
 /src/Std/ @TwoFX
 /src/Std/Tactic/BVDecide/ @hargoniX
 /src/Lean/Elab/Tactic/BVDecide/ @hargoniX
-/src/Std/Sat/ @hargoniX

RELEASES.md

@@ -8,329 +8,6 @@ This file contains work-in-progress notes for the upcoming release, as well as p
 Please check the [releases](https://github.com/leanprover/lean4/releases) page for the current status
 of each version.
 
-v4.15.0
-----------
-
-Development in progress.
-
-v4.14.0
-----------
-
-Release candidate, release notes will be copied from the branch `releases/v4.14.0` once completed.
-
-v4.13.0
-----------
-
-**Full Changelog**: https://github.com/leanprover/lean4/compare/v4.12.0...v4.13.0
-
-### Language features, tactics, and metaprograms
-
-* `structure` command
-  * [#5511](https://github.com/leanprover/lean4/pull/5511) allows structure parents to be type synonyms.
-  * [#5531](https://github.com/leanprover/lean4/pull/5531) allows default values for structure fields to be noncomputable.
-
-* `rfl` and `apply_rfl` tactics
-  * [#3714](https://github.com/leanprover/lean4/pull/3714), [#3718](https://github.com/leanprover/lean4/pull/3718) improve the `rfl` tactic and give better error messages.
-  * [#3772](https://github.com/leanprover/lean4/pull/3772) makes `rfl` no longer use kernel defeq for ground terms.
-  * [#5329](https://github.com/leanprover/lean4/pull/5329) tags `Iff.refl` with `@[refl]` (@Parcly-Taxel)
-  * [#5359](https://github.com/leanprover/lean4/pull/5359) ensures that the `rfl` tactic tries `Iff.rfl` (@Parcly-Taxel)
-
-* `unfold` tactic
-  * [#4834](https://github.com/leanprover/lean4/pull/4834) let `unfold` do zeta-delta reduction of local definitions, incorporating functionality of the Mathlib `unfold_let` tactic.
-
-* `omega` tactic
-  * [#5382](https://github.com/leanprover/lean4/pull/5382) fixes spurious error in [#5315](https://github.com/leanprover/lean4/issues/5315)
-  * [#5523](https://github.com/leanprover/lean4/pull/5523) supports `Int.toNat`
-
-* `simp` tactic
-  * [#5479](https://github.com/leanprover/lean4/pull/5479) lets `simp` apply rules with higher-order patterns.
-
-* `induction` tactic
-  * [#5494](https://github.com/leanprover/lean4/pull/5494) fixes `induction`’s "pre-tactic" block to always be indented, avoiding unintended uses of it.
-
-* `ac_nf` tactic
-  * [#5524](https://github.com/leanprover/lean4/pull/5524) adds `ac_nf`, a counterpart to `ac_rfl`, for normalizing expressions with respect to associativity and commutativity. Tests it with `BitVec` expressions.
-
-* `bv_decide`
-  * [#5211](https://github.com/leanprover/lean4/pull/5211) makes `extractLsb'` the primitive `bv_decide` understands, rather than `extractLsb` (@alexkeizer)
-  * [#5365](https://github.com/leanprover/lean4/pull/5365) adds `bv_decide` diagnoses.
-  * [#5375](https://github.com/leanprover/lean4/pull/5375) adds `bv_decide` normalization rules for `ofBool (a.getLsbD i)` and `ofBool a[i]` (@alexkeizer)
-  * [#5423](https://github.com/leanprover/lean4/pull/5423) enhances the rewriting rules of `bv_decide`
-  * [#5433](https://github.com/leanprover/lean4/pull/5433) presents the `bv_decide` counterexample at the API
-  * [#5484](https://github.com/leanprover/lean4/pull/5484) handles `BitVec.ofNat` with `Nat` fvars in `bv_decide`
-  * [#5506](https://github.com/leanprover/lean4/pull/5506), [#5507](https://github.com/leanprover/lean4/pull/5507) add `bv_normalize` rules.
-  * [#5568](https://github.com/leanprover/lean4/pull/5568) generalize the `bv_normalize` pipeline to support more general preprocessing passes
-  * [#5573](https://github.com/leanprover/lean4/pull/5573) gets `bv_normalize` up-to-date with the current `BitVec` rewrites
-  * Cleanups: [#5408](https://github.com/leanprover/lean4/pull/5408), [#5493](https://github.com/leanprover/lean4/pull/5493), [#5578](https://github.com/leanprover/lean4/pull/5578)
-
-
-* Elaboration improvements
-  * [#5266](https://github.com/leanprover/lean4/pull/5266) preserve order of overapplied arguments in `elab_as_elim` procedure.
-  * [#5510](https://github.com/leanprover/lean4/pull/5510) generalizes `elab_as_elim` to allow arbitrary motive applications.
-  * [#5283](https://github.com/leanprover/lean4/pull/5283), [#5512](https://github.com/leanprover/lean4/pull/5512) refine how named arguments suppress explicit arguments. Breaking change: some previously omitted explicit arguments may need explicit `_` arguments now.
-  * [#5376](https://github.com/leanprover/lean4/pull/5376) modifies projection instance binder info for instances, making parameters that are instance implicit in the type be implicit.
-  * [#5402](https://github.com/leanprover/lean4/pull/5402) localizes universe metavariable errors to `let` bindings and `fun` binders if possible. Makes "cannot synthesize metavariable" errors take precedence over unsolved universe level errors.
-  * [#5419](https://github.com/leanprover/lean4/pull/5419) must not reduce `ite` in the discriminant of `match`-expression when reducibility setting is `.reducible`
-  * [#5474](https://github.com/leanprover/lean4/pull/5474) have autoparams report parameter/field on failure
-  * [#5530](https://github.com/leanprover/lean4/pull/5530) makes automatic instance names about types with hygienic names be hygienic.
-
-* Deriving handlers
-  * [#5432](https://github.com/leanprover/lean4/pull/5432) makes `Repr` deriving instance handle explicit type parameters
-
-* Functional induction
-  * [#5364](https://github.com/leanprover/lean4/pull/5364) adds more equalities in context, more careful cleanup.
-
-* Linters
-  * [#5335](https://github.com/leanprover/lean4/pull/5335) fixes the unused variables linter complaining about match/tactic combinations
-  * [#5337](https://github.com/leanprover/lean4/pull/5337) fixes the unused variables linter complaining about some wildcard patterns
-
-* Other fixes
-  * [#4768](https://github.com/leanprover/lean4/pull/4768) fixes a parse error when `..` appears with a `.` on the next line
-
-* Metaprogramming
-  * [#3090](https://github.com/leanprover/lean4/pull/3090) handles level parameters in `Meta.evalExpr` (@eric-wieser)  
-  * [#5401](https://github.com/leanprover/lean4/pull/5401) instance for `Inhabited (TacticM α)` (@alexkeizer)
-  * [#5412](https://github.com/leanprover/lean4/pull/5412) expose Kernel.check for debugging purposes
-  * [#5556](https://github.com/leanprover/lean4/pull/5556) improves the "invalid projection" type inference error in `inferType`.
-  * [#5587](https://github.com/leanprover/lean4/pull/5587) allows `MVarId.assertHypotheses` to set `BinderInfo` and `LocalDeclKind`.
-  * [#5588](https://github.com/leanprover/lean4/pull/5588) adds `MVarId.tryClearMany'`, a variant of `MVarId.tryClearMany`.
-
-
-
-### Language server, widgets, and IDE extensions
-
-* [#5205](https://github.com/leanprover/lean4/pull/5205) decreases the latency of auto-completion in tactic blocks.
-* [#5237](https://github.com/leanprover/lean4/pull/5237) fixes symbol occurrence highlighting in VS Code not highlighting occurrences when moving the text cursor into the identifier from the right.
-* [#5257](https://github.com/leanprover/lean4/pull/5257) fixes several instances of incorrect auto-completions being reported.
-* [#5299](https://github.com/leanprover/lean4/pull/5299) allows auto-completion to report completions for global identifiers when the elaborator fails to provide context-specific auto-completions.
-* [#5312](https://github.com/leanprover/lean4/pull/5312) fixes the server breaking when changing whitespace after the module header.
-* [#5322](https://github.com/leanprover/lean4/pull/5322) fixes several instances of auto-completion reporting non-existent namespaces.
-* [#5428](https://github.com/leanprover/lean4/pull/5428) makes sure to always report some recent file range as progress when waiting for elaboration.
-
-
-### Pretty printing
-
-* [#4979](https://github.com/leanprover/lean4/pull/4979) make pretty printer escape identifiers that are tokens.
-* [#5389](https://github.com/leanprover/lean4/pull/5389) makes formatter use the current token table.
-* [#5513](https://github.com/leanprover/lean4/pull/5513) use breakable instead of unbreakable whitespace when formatting tokens.
-
-
-### Library
-
-* [#5222](https://github.com/leanprover/lean4/pull/5222) reduces allocations in `Json.compress`.
-* [#5231](https://github.com/leanprover/lean4/pull/5231) upstreams `Zero` and `NeZero`
-* [#5292](https://github.com/leanprover/lean4/pull/5292) refactors `Lean.Elab.Deriving.FromToJson` (@arthur-adjedj)
-* [#5415](https://github.com/leanprover/lean4/pull/5415) implements `Repr Empty` (@TomasPuverle)
-* [#5421](https://github.com/leanprover/lean4/pull/5421) implements `To/FromJSON Empty` (@TomasPuverle)
-
-* Logic
-  * [#5263](https://github.com/leanprover/lean4/pull/5263) allows simplifying `dite_not`/`decide_not` with only `Decidable (¬p)`.
-  * [#5268](https://github.com/leanprover/lean4/pull/5268) fixes binders on `ite_eq_left_iff`
-  * [#5284](https://github.com/leanprover/lean4/pull/5284) turns off `Inhabited (Sum α β)` instances
-  * [#5355](https://github.com/leanprover/lean4/pull/5355) adds simp lemmas for `LawfulBEq`
-  * [#5374](https://github.com/leanprover/lean4/pull/5374) add `Nonempty` instances for products, allowing more `partial` functions to elaborate successfully
-  * [#5447](https://github.com/leanprover/lean4/pull/5447) updates Pi instance names
-  * [#5454](https://github.com/leanprover/lean4/pull/5454) makes some instance arguments implicit
-  * [#5456](https://github.com/leanprover/lean4/pull/5456) adds `heq_comm`
-  * [#5529](https://github.com/leanprover/lean4/pull/5529) moves `@[simp]` from `exists_prop'` to `exists_prop`
-
-* `Bool`
-  * [#5228](https://github.com/leanprover/lean4/pull/5228) fills gaps in Bool lemmas
-  * [#5332](https://github.com/leanprover/lean4/pull/5332) adds notation `^^` for Bool.xor
-  * [#5351](https://github.com/leanprover/lean4/pull/5351) removes `_root_.and` (and or/not/xor) and instead exports/uses `Bool.and` (etc.).
-
-* `BitVec`
-  * [#5240](https://github.com/leanprover/lean4/pull/5240) removes BitVec simps with complicated RHS
-  * [#5247](https://github.com/leanprover/lean4/pull/5247) `BitVec.getElem_zeroExtend`
-  * [#5248](https://github.com/leanprover/lean4/pull/5248) simp lemmas for BitVec, improving confluence
-  * [#5249](https://github.com/leanprover/lean4/pull/5249) removes `@[simp]` from some BitVec lemmas
-  * [#5252](https://github.com/leanprover/lean4/pull/5252) changes `BitVec.intMin/Max` from abbrev to def
-  * [#5278](https://github.com/leanprover/lean4/pull/5278) adds `BitVec.getElem_truncate` (@tobiasgrosser)
-  * [#5281](https://github.com/leanprover/lean4/pull/5281) adds udiv/umod bitblasting for `bv_decide` (@bollu)
-  * [#5297](https://github.com/leanprover/lean4/pull/5297) `BitVec` unsigned order theoretic results
-  * [#5313](https://github.com/leanprover/lean4/pull/5313) adds more basic BitVec ordering theory for UInt
-  * [#5314](https://github.com/leanprover/lean4/pull/5314) adds `toNat_sub_of_le` (@bollu)
-  * [#5357](https://github.com/leanprover/lean4/pull/5357) adds `BitVec.truncate` lemmas
-  * [#5358](https://github.com/leanprover/lean4/pull/5358) introduces `BitVec.setWidth` to unify zeroExtend and truncate (@tobiasgrosser)
-  * [#5361](https://github.com/leanprover/lean4/pull/5361) some BitVec GetElem lemmas
-  * [#5385](https://github.com/leanprover/lean4/pull/5385) adds `BitVec.ofBool_[and|or|xor]_ofBool` theorems (@tobiasgrosser)
-  * [#5404](https://github.com/leanprover/lean4/pull/5404) more of `BitVec.getElem_*` (@tobiasgrosser)
-  * [#5410](https://github.com/leanprover/lean4/pull/5410) BitVec analogues of `Nat.{mul_two, two_mul, mul_succ, succ_mul}` (@bollu)
-  * [#5411](https://github.com/leanprover/lean4/pull/5411) `BitVec.toNat_{add,sub,mul_of_lt}` for BitVector non-overflow reasoning (@bollu)
-  * [#5413](https://github.com/leanprover/lean4/pull/5413) adds `_self`, `_zero`, and `_allOnes` for `BitVec.[and|or|xor]` (@tobiasgrosser)
-  * [#5416](https://github.com/leanprover/lean4/pull/5416) adds LawCommIdentity + IdempotentOp for `BitVec.[and|or|xor]` (@tobiasgrosser)
-  * [#5418](https://github.com/leanprover/lean4/pull/5418) decidable quantifers for BitVec
-  * [#5450](https://github.com/leanprover/lean4/pull/5450) adds `BitVec.toInt_[intMin|neg|neg_of_ne_intMin]` (@tobiasgrosser)
-  * [#5459](https://github.com/leanprover/lean4/pull/5459) missing BitVec lemmas
-  * [#5469](https://github.com/leanprover/lean4/pull/5469) adds `BitVec.[not_not, allOnes_shiftLeft_or_shiftLeft, allOnes_shiftLeft_and_shiftLeft]` (@luisacicolini)
-  * [#5478](https://github.com/leanprover/lean4/pull/5478) adds `BitVec.(shiftLeft_add_distrib, shiftLeft_ushiftRight)` (@luisacicolini)
-  * [#5487](https://github.com/leanprover/lean4/pull/5487) adds `sdiv_eq`, `smod_eq` to allow `sdiv`/`smod` bitblasting (@bollu)
-  * [#5491](https://github.com/leanprover/lean4/pull/5491) adds `BitVec.toNat_[abs|sdiv|smod]` (@tobiasgrosser)
-  * [#5492](https://github.com/leanprover/lean4/pull/5492) `BitVec.(not_sshiftRight, not_sshiftRight_not, getMsb_not, msb_not)` (@luisacicolini)
-  * [#5499](https://github.com/leanprover/lean4/pull/5499) `BitVec.Lemmas` - drop non-terminal simps (@tobiasgrosser)
-  * [#5505](https://github.com/leanprover/lean4/pull/5505) unsimps `BitVec.divRec_succ'`
-  * [#5508](https://github.com/leanprover/lean4/pull/5508) adds `BitVec.getElem_[add|add_add_bool|mul|rotateLeft|rotateRight…` (@tobiasgrosser)
-  * [#5554](https://github.com/leanprover/lean4/pull/5554) adds `Bitvec.[add, sub, mul]_eq_xor` and `width_one_cases` (@luisacicolini)
-
-* `List`
-  * [#5242](https://github.com/leanprover/lean4/pull/5242) improve naming for `List.mergeSort` lemmas
-  * [#5302](https://github.com/leanprover/lean4/pull/5302) provide `mergeSort` comparator autoParam
-  * [#5373](https://github.com/leanprover/lean4/pull/5373) fix name of `List.length_mergeSort`
-  * [#5377](https://github.com/leanprover/lean4/pull/5377) upstream `map_mergeSort`
-  * [#5378](https://github.com/leanprover/lean4/pull/5378) modify signature of lemmas about `mergeSort`
-  * [#5245](https://github.com/leanprover/lean4/pull/5245) avoid importing `List.Basic` without List.Impl
-  * [#5260](https://github.com/leanprover/lean4/pull/5260) review of List API
-  * [#5264](https://github.com/leanprover/lean4/pull/5264) review of List API
-  * [#5269](https://github.com/leanprover/lean4/pull/5269) remove HashMap's duplicated Pairwise and Sublist
-  * [#5271](https://github.com/leanprover/lean4/pull/5271) remove @[simp] from `List.head_mem` and similar
-  * [#5273](https://github.com/leanprover/lean4/pull/5273) lemmas about `List.attach`
-  * [#5275](https://github.com/leanprover/lean4/pull/5275) reverse direction of `List.tail_map`
-  * [#5277](https://github.com/leanprover/lean4/pull/5277) more `List.attach` lemmas
-  * [#5285](https://github.com/leanprover/lean4/pull/5285) `List.count` lemmas
-  * [#5287](https://github.com/leanprover/lean4/pull/5287) use boolean predicates in `List.filter`
-  * [#5289](https://github.com/leanprover/lean4/pull/5289) `List.mem_ite_nil_left` and analogues
-  * [#5293](https://github.com/leanprover/lean4/pull/5293) cleanup of `List.findIdx` / `List.take` lemmas
-  * [#5294](https://github.com/leanprover/lean4/pull/5294) switch primes on `List.getElem_take`
-  * [#5300](https://github.com/leanprover/lean4/pull/5300) more `List.findIdx` theorems
-  * [#5310](https://github.com/leanprover/lean4/pull/5310) fix `List.all/any` lemmas
-  * [#5311](https://github.com/leanprover/lean4/pull/5311) fix `List.countP` lemmas
-  * [#5316](https://github.com/leanprover/lean4/pull/5316) `List.tail` lemma
-  * [#5331](https://github.com/leanprover/lean4/pull/5331) fix implicitness of `List.getElem_mem`
-  * [#5350](https://github.com/leanprover/lean4/pull/5350) `List.replicate` lemmas
-  * [#5352](https://github.com/leanprover/lean4/pull/5352) `List.attachWith` lemmas
-  * [#5353](https://github.com/leanprover/lean4/pull/5353) `List.head_mem_head?`
-  * [#5360](https://github.com/leanprover/lean4/pull/5360) lemmas about `List.tail`
-  * [#5391](https://github.com/leanprover/lean4/pull/5391) review of `List.erase` / `List.find` lemmas
-  * [#5392](https://github.com/leanprover/lean4/pull/5392) `List.fold` / `attach` lemmas
-  * [#5393](https://github.com/leanprover/lean4/pull/5393) `List.fold` relators
-  * [#5394](https://github.com/leanprover/lean4/pull/5394) lemmas about `List.maximum?`
-  * [#5403](https://github.com/leanprover/lean4/pull/5403) theorems about `List.toArray`
-  * [#5405](https://github.com/leanprover/lean4/pull/5405) reverse direction of `List.set_map`
-  * [#5448](https://github.com/leanprover/lean4/pull/5448) add lemmas about `List.IsPrefix` (@Command-Master)
-  * [#5460](https://github.com/leanprover/lean4/pull/5460) missing `List.set_replicate_self`
-  * [#5518](https://github.com/leanprover/lean4/pull/5518) rename `List.maximum?` to `max?`
-  * [#5519](https://github.com/leanprover/lean4/pull/5519) upstream `List.fold` lemmas
-  * [#5520](https://github.com/leanprover/lean4/pull/5520) restore `@[simp]` on `List.getElem_mem` etc.
-  * [#5521](https://github.com/leanprover/lean4/pull/5521) List simp fixes
-  * [#5550](https://github.com/leanprover/lean4/pull/5550) `List.unattach` and simp lemmas
-  * [#5594](https://github.com/leanprover/lean4/pull/5594) induction-friendly `List.min?_cons`
-
-* `Array`
-  * [#5246](https://github.com/leanprover/lean4/pull/5246) cleanup imports of Array.Lemmas
-  * [#5255](https://github.com/leanprover/lean4/pull/5255) split Init.Data.Array.Lemmas for better bootstrapping
-  * [#5288](https://github.com/leanprover/lean4/pull/5288) rename `Array.data` to `Array.toList`
-  * [#5303](https://github.com/leanprover/lean4/pull/5303) cleanup of `List.getElem_append` variants
-  * [#5304](https://github.com/leanprover/lean4/pull/5304) `Array.not_mem_empty`
-  * [#5400](https://github.com/leanprover/lean4/pull/5400) reorganization in Array/Basic
-  * [#5420](https://github.com/leanprover/lean4/pull/5420) make `Array` functions either semireducible or use structural recursion
-  * [#5422](https://github.com/leanprover/lean4/pull/5422) refactor `DecidableEq (Array α)`
-  * [#5452](https://github.com/leanprover/lean4/pull/5452) refactor of Array
-  * [#5458](https://github.com/leanprover/lean4/pull/5458) cleanup of Array docstrings after refactor
-  * [#5461](https://github.com/leanprover/lean4/pull/5461) restore `@[simp]` on `Array.swapAt!_def`
-  * [#5465](https://github.com/leanprover/lean4/pull/5465) improve Array GetElem lemmas
-  * [#5466](https://github.com/leanprover/lean4/pull/5466) `Array.foldX` lemmas
-  * [#5472](https://github.com/leanprover/lean4/pull/5472) @[simp] lemmas about `List.toArray`
-  * [#5485](https://github.com/leanprover/lean4/pull/5485) reverse simp direction for `toArray_concat`
-  * [#5514](https://github.com/leanprover/lean4/pull/5514) `Array.eraseReps`
-  * [#5515](https://github.com/leanprover/lean4/pull/5515) upstream `Array.qsortOrd`
-  * [#5516](https://github.com/leanprover/lean4/pull/5516) upstream `Subarray.empty`
-  * [#5526](https://github.com/leanprover/lean4/pull/5526) fix name of `Array.length_toList`
-  * [#5527](https://github.com/leanprover/lean4/pull/5527) reduce use of deprecated lemmas in Array
-  * [#5534](https://github.com/leanprover/lean4/pull/5534) cleanup of Array GetElem lemmas
-  * [#5536](https://github.com/leanprover/lean4/pull/5536) fix `Array.modify` lemmas
-  * [#5551](https://github.com/leanprover/lean4/pull/5551) upstream `Array.flatten` lemmas
-  * [#5552](https://github.com/leanprover/lean4/pull/5552) switch obvious cases of array "bang"`[]!` indexing to rely on hypothesis (@TomasPuverle)
-  * [#5577](https://github.com/leanprover/lean4/pull/5577) add missing simp to `Array.size_feraseIdx`
-  * [#5586](https://github.com/leanprover/lean4/pull/5586) `Array/Option.unattach`
-
-* `Option`
-  * [#5272](https://github.com/leanprover/lean4/pull/5272) remove @[simp] from `Option.pmap/pbind` and add simp lemmas
-  * [#5307](https://github.com/leanprover/lean4/pull/5307) restoring Option simp confluence
-  * [#5354](https://github.com/leanprover/lean4/pull/5354) remove @[simp] from `Option.bind_map`
-  * [#5532](https://github.com/leanprover/lean4/pull/5532) `Option.attach`
-  * [#5539](https://github.com/leanprover/lean4/pull/5539) fix explicitness of `Option.mem_toList`
-
-* `Nat`
-  * [#5241](https://github.com/leanprover/lean4/pull/5241) add @[simp] to `Nat.add_eq_zero_iff`
-  * [#5261](https://github.com/leanprover/lean4/pull/5261) Nat bitwise lemmas
-  * [#5262](https://github.com/leanprover/lean4/pull/5262) `Nat.testBit_add_one` should not be a global simp lemma
-  * [#5267](https://github.com/leanprover/lean4/pull/5267) protect some Nat bitwise theorems
-  * [#5305](https://github.com/leanprover/lean4/pull/5305) rename Nat bitwise lemmas
-  * [#5306](https://github.com/leanprover/lean4/pull/5306) add `Nat.self_sub_mod` lemma
-  * [#5503](https://github.com/leanprover/lean4/pull/5503) restore @[simp] to upstreamed `Nat.lt_off_iff`
-
-* `Int`
-  * [#5301](https://github.com/leanprover/lean4/pull/5301) rename `Int.div/mod` to `Int.tdiv/tmod`
-  * [#5320](https://github.com/leanprover/lean4/pull/5320) add `ediv_nonneg_of_nonpos_of_nonpos` to DivModLemmas (@sakehl)
-
-* `Fin`
-  * [#5250](https://github.com/leanprover/lean4/pull/5250) missing lemma about `Fin.ofNat'`
-  * [#5356](https://github.com/leanprover/lean4/pull/5356) `Fin.ofNat'` uses `NeZero`
-  * [#5379](https://github.com/leanprover/lean4/pull/5379) remove some @[simp]s from Fin lemmas
-  * [#5380](https://github.com/leanprover/lean4/pull/5380) missing Fin @[simp] lemmas
-
-* `HashMap`
-  * [#5244](https://github.com/leanprover/lean4/pull/5244) (`DHashMap`|`HashMap`|`HashSet`).(`getKey?`|`getKey`|`getKey!`|`getKeyD`)
-  * [#5362](https://github.com/leanprover/lean4/pull/5362) remove the last use of `Lean.(HashSet|HashMap)`
-  * [#5369](https://github.com/leanprover/lean4/pull/5369) `HashSet.ofArray`
-  * [#5370](https://github.com/leanprover/lean4/pull/5370) `HashSet.partition`
-  * [#5581](https://github.com/leanprover/lean4/pull/5581) `Singleton`/`Insert`/`Union` instances for `HashMap`/`Set`
-  * [#5582](https://github.com/leanprover/lean4/pull/5582) `HashSet.all`/`any`
-  * [#5590](https://github.com/leanprover/lean4/pull/5590) adding `Insert`/`Singleton`/`Union` instances for `HashMap`/`Set.Raw`
-  * [#5591](https://github.com/leanprover/lean4/pull/5591) `HashSet.Raw.all/any`
-
-* `Monads`
-  * [#5463](https://github.com/leanprover/lean4/pull/5463) upstream some monad lemmas
-  * [#5464](https://github.com/leanprover/lean4/pull/5464) adjust simp attributes on monad lemmas
-  * [#5522](https://github.com/leanprover/lean4/pull/5522) more monadic simp lemmas
-
-* Simp lemma cleanup
-  * [#5251](https://github.com/leanprover/lean4/pull/5251) remove redundant simp annotations
-  * [#5253](https://github.com/leanprover/lean4/pull/5253) remove Int simp lemmas that can't fire
-  * [#5254](https://github.com/leanprover/lean4/pull/5254) variables appearing on both sides of an iff should be implicit
-  * [#5381](https://github.com/leanprover/lean4/pull/5381) cleaning up redundant simp lemmas
-
-
-### Compiler, runtime, and FFI
-
-* [#4685](https://github.com/leanprover/lean4/pull/4685) fixes a typo in the C `run_new_frontend` signature
-* [#4729](https://github.com/leanprover/lean4/pull/4729) has IR checker suggest using `noncomputable`
-* [#5143](https://github.com/leanprover/lean4/pull/5143) adds a shared library for Lake
-* [#5437](https://github.com/leanprover/lean4/pull/5437) removes (syntactically) duplicate imports (@euprunin)
-* [#5462](https://github.com/leanprover/lean4/pull/5462) updates `src/lake/lakefile.toml` to the adjusted Lake build process
-* [#5541](https://github.com/leanprover/lean4/pull/5541) removes new shared libs before build to better support Windows
-* [#5558](https://github.com/leanprover/lean4/pull/5558) make `lean.h` compile with MSVC (@kant2002)
-* [#5564](https://github.com/leanprover/lean4/pull/5564) removes non-conforming size-0 arrays (@eric-wieser)
-
-
-### Lake
-  * Reservoir build cache. Lake will now attempt to fetch a pre-built copy of the package from Reservoir before building it. This is only enabled for packages in the leanprover or leanprover-community organizations on versions indexed by Reservoir. Users can force Lake to build packages from the source by passing --no-cache on the CLI or by setting the  LAKE_NO_CACHE environment variable to true. [#5486](https://github.com/leanprover/lean4/pull/5486), [#5572](https://github.com/leanprover/lean4/pull/5572), [#5583](https://github.com/leanprover/lean4/pull/5583), [#5600](https://github.com/leanprover/lean4/pull/5600), [#5641](https://github.com/leanprover/lean4/pull/5641), [#5642](https://github.com/leanprover/lean4/pull/5642).
-  * [#5504](https://github.com/leanprover/lean4/pull/5504) lake new and lake init now produce TOML configurations by default.
-  * [#5878](https://github.com/leanprover/lean4/pull/5878) fixes a serious issue where Lake would delete path dependencies when attempting to cleanup a dependency required with an incorrect name.
-
-  * **Breaking changes**
-    * [#5641](https://github.com/leanprover/lean4/pull/5641) A Lake build of target within a package will no longer build a package's dependencies package-level extra target dependencies. At the technical level, a package's extraDep facet no longer transitively builds its dependencies’ extraDep facets (which include their extraDepTargets).
-
-### Documentation fixes
-
-* [#3918](https://github.com/leanprover/lean4/pull/3918) `@[builtin_doc]` attribute (@digama0)
-* [#4305](https://github.com/leanprover/lean4/pull/4305) explains the borrow syntax (@eric-wieser)
-* [#5349](https://github.com/leanprover/lean4/pull/5349) adds documentation for `groupBy.loop` (@vihdzp)
-* [#5473](https://github.com/leanprover/lean4/pull/5473) fixes typo in `BitVec.mul` docstring (@llllvvuu)
-* [#5476](https://github.com/leanprover/lean4/pull/5476) fixes typos in `Lean.MetavarContext`
-* [#5481](https://github.com/leanprover/lean4/pull/5481) removes mention of `Lean.withSeconds` (@alexkeizer)
-* [#5497](https://github.com/leanprover/lean4/pull/5497) updates documentation and tests for `toUIntX` functions (@TomasPuverle)
-* [#5087](https://github.com/leanprover/lean4/pull/5087) mentions that `inferType` does not ensure type correctness
-* Many fixes to spelling across the doc-strings, (@euprunin): [#5425](https://github.com/leanprover/lean4/pull/5425) [#5426](https://github.com/leanprover/lean4/pull/5426) [#5427](https://github.com/leanprover/lean4/pull/5427) [#5430](https://github.com/leanprover/lean4/pull/5430)  [#5431](https://github.com/leanprover/lean4/pull/5431) [#5434](https://github.com/leanprover/lean4/pull/5434) [#5435](https://github.com/leanprover/lean4/pull/5435) [#5436](https://github.com/leanprover/lean4/pull/5436) [#5438](https://github.com/leanprover/lean4/pull/5438) [#5439](https://github.com/leanprover/lean4/pull/5439) [#5440](https://github.com/leanprover/lean4/pull/5440) [#5599](https://github.com/leanprover/lean4/pull/5599)
-
-### Changes to CI
-
-* [#5343](https://github.com/leanprover/lean4/pull/5343) allows addition of `release-ci` label via comment (@thorimur)
-* [#5344](https://github.com/leanprover/lean4/pull/5344) sets check level correctly during workflow (@thorimur)
-* [#5444](https://github.com/leanprover/lean4/pull/5444) Mathlib's `lean-pr-testing-NNNN` branches should use Batteries' `lean-pr-testing-NNNN` branches
-* [#5489](https://github.com/leanprover/lean4/pull/5489) commit `lake-manifest.json` when updating `lean-pr-testing` branches
-* [#5490](https://github.com/leanprover/lean4/pull/5490) use separate secrets for commenting and branching in `pr-release.yml`
-
 v4.12.0
 ----------
 

doc/make/index.md

@@ -1,6 +1,6 @@
-These are instructions to set up a working development environment for those who wish to make changes to Lean itself. It is part of the [Development Guide](../dev/index.md).
+These are instructions to set up a working development environment for those who wish to make changes to Lean itself. It is part of the [Development Guide](doc/dev/index.md).
 
-We strongly suggest that new users instead follow the [Quickstart](../quickstart.md) to get started using Lean, since this sets up an environment that can automatically manage multiple Lean toolchain versions, which is necessary when working within the Lean ecosystem.
+We strongly suggest that new users instead follow the [Quickstart](doc/quickstart.md) to get started using Lean, since this sets up an environment that can automatically manage multiple Lean toolchain versions, which is necessary when working within the Lean ecosystem.
 
 Requirements
 ------------

doc/make/msys2.md

@@ -15,13 +15,6 @@ Mode](https://docs.microsoft.com/en-us/windows/apps/get-started/enable-your-devi
 which will allow Lean to create symlinks that e.g. enable go-to-definition in
 the stdlib.
 
-## Installing the Windows SDK
-
-Install the Windows SDK from [Microsoft](https://developer.microsoft.com/en-us/windows/downloads/windows-sdk/).
-The oldest supported version is 10.0.18362.0. If you installed the Windows SDK to the default location,
-then there should be a directory with the version number at `C:\Program Files (x86)\Windows Kits\10\Include`.
-If there are multiple directories, only the highest version number matters.
-
 ## Installing dependencies
 
 [The official webpage of MSYS2][msys2] provides one-click installers.

doc/monads/applicatives.lean

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

doc/monads/laws.lean

@@ -128,8 +128,8 @@ Applying the identity function through an applicative structure should not chang
 values or structure.  For example:
 -/
 instance : Applicative List where
-  pure := List.singleton
-  seq f x := List.flatMap f fun y => Functor.map y (x ())
+  pure := List.pure
+  seq f x := List.bind f fun y => Functor.map y (x ())
 
 #eval pure id <*> [1, 2, 3]  -- [1, 2, 3]
 /-!
@@ -235,8 +235,8 @@ structure or its values.
 Left identity is `x >>= pure = x` and is demonstrated by the following examples on a monadic `List`:
 -/
 instance : Monad List  where
-  pure := List.singleton
-  bind := List.flatMap
+  pure := List.pure
+  bind := List.bind
 
 def a := ["apple", "orange"]
 

doc/monads/monads.lean

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

doc/setup.md

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

flake.nix

@@ -38,11 +38,7 @@
           # more convenient `ctest` output
           CTEST_OUTPUT_ON_FAILURE = 1;
         } // pkgs.lib.optionalAttrs pkgs.stdenv.isLinux {
-          GMP = (pkgsDist.gmp.override { withStatic = true; }).overrideAttrs (attrs:
-            pkgs.lib.optionalAttrs (pkgs.stdenv.system == "aarch64-linux") {
-              # would need additional linking setup on Linux aarch64, we don't use it anywhere else either
-              hardeningDisable = [ "stackprotector" ];
-            });
+          GMP = pkgsDist.gmp.override { withStatic = true; };
           LIBUV = pkgsDist.libuv.overrideAttrs (attrs: {
             configureFlags = ["--enable-static"];
             hardeningDisable = [ "stackprotector" ];

script/prepare-llvm-linux.sh

@@ -64,7 +64,7 @@ fi
 # use `-nostdinc` to make sure headers are not visible by default (in particular, not to `#include_next` in the clang headers),
 # but do not change sysroot so users can still link against system libs
 echo -n " -DLEANC_INTERNAL_FLAGS='-nostdinc -isystem ROOT/include/clang' -DLEANC_CC=ROOT/bin/clang"
-echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/glibc ROOT/lib/glibc/libc_nonshared.a ROOT/lib/glibc/libpthread_nonshared.a -Wl,--as-needed -Wl,-Bstatic -lgmp -lunwind -luv -Wl,-Bdynamic -Wl,--no-as-needed -fuse-ld=lld'"
+echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -L ROOT/lib/glibc ROOT/lib/glibc/libc_nonshared.a ROOT/lib/glibc/libpthread_nonshared.a -Wl,--as-needed -Wl,-Bstatic -lgmp -lunwind -luv -lpthread -ldl -lrt -Wl,-Bdynamic -Wl,--no-as-needed -fuse-ld=lld'"
 # when not using the above flags, link GMP dynamically/as usual
 echo -n " -DLEAN_EXTRA_LINKER_FLAGS='-Wl,--as-needed -lgmp -luv -lpthread -ldl -lrt -Wl,--no-as-needed'"
 # do not set `LEAN_CC` for tests

script/prepare-llvm-mingw.sh

@@ -31,20 +31,14 @@ cp /clang64/lib/{crtbegin,crtend,crt2,dllcrt2}.o stage1/lib/
 # runtime
 (cd llvm; cp --parents lib/clang/*/lib/*/libclang_rt.builtins* ../stage1)
 # further dependencies
-# Note: even though we're linking against libraries like `libbcrypt.a` which appear to be static libraries from the file name,
-# we're not actually linking statically against the code.
-# Rather, `libbcrypt.a` is an import library (see https://en.wikipedia.org/wiki/Dynamic-link_library#Import_libraries) that just
-# tells the compiler how to dynamically link against `bcrypt.dll` (which is located in the System32 folder).
-# This distinction is relevant specifically for `libicu.a`/`icu.dll` because there we want updates to the time zone database to
-# be delivered to users via Windows Update without having to recompile Lean or Lean programs.
-cp /clang64/lib/lib{m,bcrypt,mingw32,moldname,mingwex,msvcrt,pthread,advapi32,shell32,user32,kernel32,ucrtbase,psapi,iphlpapi,userenv,ws2_32,dbghelp,ole32,icu}.* /clang64/lib/libgmp.a /clang64/lib/libuv.a llvm/lib/lib{c++,c++abi,unwind}.a stage1/lib/
+cp /clang64/lib/lib{m,bcrypt,mingw32,moldname,mingwex,msvcrt,pthread,advapi32,shell32,user32,kernel32,ucrtbase,psapi,iphlpapi,userenv,ws2_32,dbghelp,ole32}.* /clang64/lib/libgmp.a /clang64/lib/libuv.a llvm/lib/lib{c++,c++abi,unwind}.a stage1/lib/
 echo -n " -DLEAN_STANDALONE=ON"
 echo -n " -DCMAKE_C_COMPILER=$PWD/stage1/bin/clang.exe -DCMAKE_C_COMPILER_WORKS=1 -DCMAKE_CXX_COMPILER=$PWD/llvm/bin/clang++.exe -DCMAKE_CXX_COMPILER_WORKS=1 -DLEAN_CXX_STDLIB='-lc++ -lc++abi'"
 echo -n " -DSTAGE0_CMAKE_C_COMPILER=clang -DSTAGE0_CMAKE_CXX_COMPILER=clang++"
 echo -n " -DLEAN_EXTRA_CXX_FLAGS='--sysroot $PWD/llvm -idirafter /clang64/include/'"
 echo -n " -DLEANC_INTERNAL_FLAGS='--sysroot ROOT -nostdinc -isystem ROOT/include/clang' -DLEANC_CC=ROOT/bin/clang.exe"
 echo -n " -DLEANC_INTERNAL_LINKER_FLAGS='-L ROOT/lib -static-libgcc -Wl,-Bstatic -lgmp $(pkg-config --static --libs libuv) -lunwind -Wl,-Bdynamic -fuse-ld=lld'"
-# when not using the above flags, link GMP dynamically/as usual. Always link ICU dynamically.
+# when not using the above flags, link GMP dynamically/as usual
 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"

src/CMakeLists.txt

@@ -10,15 +10,13 @@ endif()
 include(ExternalProject)
 project(LEAN CXX C)
 set(LEAN_VERSION_MAJOR 4)
-set(LEAN_VERSION_MINOR 15)
+set(LEAN_VERSION_MINOR 12)
 set(LEAN_VERSION_PATCH 0)
 set(LEAN_VERSION_IS_RELEASE 0)  # This number is 1 in the release revision, and 0 otherwise.
 set(LEAN_SPECIAL_VERSION_DESC "" CACHE STRING "Additional version description like 'nightly-2018-03-11'")
 set(LEAN_VERSION_STRING "${LEAN_VERSION_MAJOR}.${LEAN_VERSION_MINOR}.${LEAN_VERSION_PATCH}")
 if (LEAN_SPECIAL_VERSION_DESC)
   string(APPEND LEAN_VERSION_STRING "-${LEAN_SPECIAL_VERSION_DESC}")
-elseif (NOT LEAN_VERSION_IS_RELEASE)
-  string(APPEND LEAN_VERSION_STRING "-pre")
 endif()
 
 set(LEAN_PLATFORM_TARGET "" CACHE STRING "LLVM triple of the target platform")
@@ -157,10 +155,6 @@ endif ()
 # We want explicit stack probes in huge Lean stack frames for robust stack overflow detection
 string(APPEND LEANC_EXTRA_FLAGS " -fstack-clash-protection")
 
-# This makes signed integer overflow guaranteed to match 2's complement.
-string(APPEND CMAKE_CXX_FLAGS " -fwrapv")
-string(APPEND LEANC_EXTRA_FLAGS " -fwrapv")
-
 if(NOT MULTI_THREAD)
   message(STATUS "Disabled multi-thread support, it will not be safe to run multiple threads in parallel")
   set(AUTO_THREAD_FINALIZATION OFF)
@@ -303,23 +297,6 @@ if(NOT LEAN_STANDALONE)
   string(APPEND LEAN_EXTRA_LINKER_FLAGS " ${LIBUV_LIBRARIES}")
 endif()
 
-# Windows SDK (for ICU)
-if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  # Pass 'tools' to skip MSVC version check (as MSVC/Visual Studio is not necessarily installed)
-  find_package(WindowsSDK REQUIRED COMPONENTS tools)
-
-  # This will give a semicolon-separated list of include directories
-  get_windowssdk_include_dirs(${WINDOWSSDK_LATEST_DIR} WINDOWSSDK_INCLUDE_DIRS)
-
-  # To successfully build against Windows SDK headers, the Windows SDK headers must have lower
-  # priority than other system headers, so use `-idirafter`. Unfortunately, CMake does not
-  # support this using `include_directories`.
-  string(REPLACE ";" "\" -idirafter \"" WINDOWSSDK_INCLUDE_DIRS "${WINDOWSSDK_INCLUDE_DIRS}")
-  string(APPEND CMAKE_CXX_FLAGS " -idirafter \"${WINDOWSSDK_INCLUDE_DIRS}\"")
-
-  string(APPEND LEAN_EXTRA_LINKER_FLAGS " -licu")
-endif()
-
 # ccache
 if(CCACHE AND NOT CMAKE_CXX_COMPILER_LAUNCHER AND NOT CMAKE_C_COMPILER_LAUNCHER)
   find_program(CCACHE_PATH ccache)
@@ -503,7 +480,7 @@ endif()
 # Git HASH
 if(USE_GITHASH)
   include(GetGitRevisionDescription)
-  get_git_head_revision(GIT_REFSPEC GIT_SHA1 ALLOW_LOOKING_ABOVE_CMAKE_SOURCE_DIR)
+  get_git_head_revision(GIT_REFSPEC GIT_SHA1)
   if(${GIT_SHA1} MATCHES "GITDIR-NOTFOUND")
     message(STATUS "Failed to read git_sha1")
     set(GIT_SHA1 "")

src/Init.lean

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

src/Init/Control/Basic.lean

@@ -8,42 +8,6 @@ import Init.Core
 
 universe u v w
 
-/--
-A `ForIn'` instance, which handles `for h : x in c do`,
-can also handle `for x in x do` by ignoring `h`, and so provides a `ForIn` instance.
-
-Note that this instance will cause a potentially non-defeq duplication if both `ForIn` and `ForIn'`
-instances are provided for the same type.
--/
--- We set the priority to 500 so it is below the default,
--- but still above the low priority instance from `Stream`.
-instance (priority := 500) instForInOfForIn' [ForIn' m ρ α d] : ForIn m ρ α where
-  forIn x b f := forIn' x b fun a _ => f a
-
-@[simp] theorem forIn'_eq_forIn [d : Membership α ρ] [ForIn' m ρ α d] {β} [Monad m] (x : ρ) (b : β)
-    (f : (a : α) → a ∈ x → β → m (ForInStep β)) (g : (a : α) → β → m (ForInStep β))
-    (h : ∀ a m b, f a m b = g a b) :
-    forIn' x b f = forIn x b g := by
-  simp [instForInOfForIn']
-  congr
-  apply funext
-  intro a
-  apply funext
-  intro m
-  apply funext
-  intro b
-  simp [h]
-  rfl
-
-/-- Extract the value from a `ForInStep`, ignoring whether it is `done` or `yield`. -/
-def ForInStep.value (x : ForInStep α) : α :=
-  match x with
-  | ForInStep.done b => b
-  | ForInStep.yield b => b
-
-@[simp] theorem ForInStep.value_done (b : β) : (ForInStep.done b).value = b := rfl
-@[simp] theorem ForInStep.value_yield (b : β) : (ForInStep.yield b).value = b := rfl
-
 @[reducible]
 def Functor.mapRev {f : Type u → Type v} [Functor f] {α β : Type u} : f α → (α → β) → f β :=
   fun a f => f <$> a

src/Init/Control/Lawful/Instances.lean

@@ -7,7 +7,6 @@ prelude
 import Init.Control.Lawful.Basic
 import Init.Control.Except
 import Init.Control.StateRef
-import Init.Ext
 
 open Function
 
@@ -15,7 +14,7 @@ open Function
 
 namespace ExceptT
 
-@[ext] theorem ext {x y : ExceptT ε m α} (h : x.run = y.run) : x = y := by
+theorem ext {x y : ExceptT ε m α} (h : x.run = y.run) : x = y := by
   simp [run] at h
   assumption
 
@@ -106,7 +105,7 @@ instance : LawfulFunctor (Except ε) := inferInstance
 
 namespace ReaderT
 
-@[ext] theorem ext {x y : ReaderT ρ m α} (h : ∀ ctx, x.run ctx = y.run ctx) : x = y := by
+theorem ext {x y : ReaderT ρ m α} (h : ∀ ctx, x.run ctx = y.run ctx) : x = y := by
   simp [run] at h
   exact funext h
 
@@ -168,7 +167,7 @@ instance [Monad m] [LawfulMonad m] : LawfulMonad (StateRefT' ω σ m) :=
 
 namespace StateT
 
-@[ext] theorem ext {x y : StateT σ m α} (h : ∀ s, x.run s = y.run s) : x = y :=
+theorem ext {x y : StateT σ m α} (h : ∀ s, x.run s = y.run s) : x = y :=
   funext h
 
 @[simp] theorem run'_eq [Monad m] (x : StateT σ m α) (s : σ) : run' x s = (·.1) <$> run x s :=

src/Init/Control/StateRef.lean

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

src/Init/Conv.lean

@@ -7,7 +7,6 @@ Notation for operators defined at Prelude.lean
 -/
 prelude
 import Init.Tactics
-import Init.Meta
 
 namespace Lean.Parser.Tactic.Conv
 
@@ -47,20 +46,12 @@ scoped syntax (name := withAnnotateState)
 /-- `skip` does nothing. -/
 syntax (name := skip) "skip" : conv
 
-/--
-Traverses into the left subterm of a binary operator.
-
-In general, for an `n`-ary operator, it traverses into the second to last argument.
-It is a synonym for `arg -2`.
--/
+/-- Traverses into the left subterm of a binary operator.
+(In general, for an `n`-ary operator, it traverses into the second to last argument.) -/
 syntax (name := lhs) "lhs" : conv
 
-/--
-Traverses into the right subterm of a binary operator.
-
-In general, for an `n`-ary operator, it traverses into the last argument.
-It is a synonym for `arg -1`.
--/
+/-- Traverses into the right subterm of a binary operator.
+(In general, for an `n`-ary operator, it traverses into the last argument.) -/
 syntax (name := rhs) "rhs" : conv
 
 /-- Traverses into the function of a (unary) function application.
@@ -83,17 +74,13 @@ subgoals for all the function arguments. For example, if the target is `f x y` t
 `congr` produces two subgoals, one for `x` and one for `y`. -/
 syntax (name := congr) "congr" : conv
 
-syntax argArg := "@"? "-"? num
-
 /--
 * `arg i` traverses into the `i`'th argument of the target. For example if the
   target is `f a b c d` then `arg 1` traverses to `a` and `arg 3` traverses to `c`.
-  The index may be negative; `arg -1` traverses into the last argument,
-  `arg -2` into the second-to-last argument, and so on.
 * `arg @i` is the same as `arg i` but it counts all arguments instead of just the
   explicit arguments.
 * `arg 0` traverses into the function. If the target is `f a b c d`, `arg 0` traverses into `f`. -/
-syntax (name := arg) "arg " argArg : conv
+syntax (name := arg) "arg " "@"? num : conv
 
 /-- `ext x` traverses into a binder (a `fun x => e` or `∀ x, e` expression)
 to target `e`, introducing name `x` in the process. -/
@@ -143,11 +130,11 @@ For example, if we are searching for `f _` in `f (f a) = f b`:
 syntax (name := pattern) "pattern " (occs)? term : conv
 
 /-- `rw [thm]` rewrites the target using `thm`. See the `rw` tactic for more information. -/
-syntax (name := rewrite) "rewrite" optConfig rwRuleSeq : conv
+syntax (name := rewrite) "rewrite" (config)? rwRuleSeq : conv
 
 /-- `simp [thm]` performs simplification using `thm` and marked `@[simp]` lemmas.
 See the `simp` tactic for more information. -/
-syntax (name := simp) "simp" optConfig (discharger)? (&" only")?
+syntax (name := simp) "simp" (config)? (discharger)? (&" only")?
   (" [" withoutPosition((simpStar <|> simpErase <|> simpLemma),*) "]")? : conv
 
 /--
@@ -164,7 +151,7 @@ example (a : Nat): (0 + 0) = a - a := by
     rw [← Nat.sub_self a]
 ```
 -/
-syntax (name := dsimp) "dsimp" optConfig (discharger)? (&" only")?
+syntax (name := dsimp) "dsimp" (config)? (discharger)? (&" only")?
   (" [" withoutPosition((simpErase <|> simpLemma),*) "]")? : conv
 
 /-- `simp_match` simplifies match expressions. For example,
@@ -260,12 +247,12 @@ macro (name := failIfSuccess) tk:"fail_if_success " s:convSeq : conv =>
 
 /-- `rw [rules]` applies the given list of rewrite rules to the target.
 See the `rw` tactic for more information. -/
-macro "rw" c:optConfig s:rwRuleSeq : conv => `(conv| rewrite $c:optConfig $s)
+macro "rw" c:(config)? s:rwRuleSeq : conv => `(conv| rewrite $[$c]? $s)
 
-/-- `erw [rules]` is a shorthand for `rw (transparency := .default) [rules]`.
+/-- `erw [rules]` is a shorthand for `rw (config := { transparency := .default }) [rules]`.
 This does rewriting up to unfolding of regular definitions (by comparison to regular `rw`
 which only unfolds `@[reducible]` definitions). -/
-macro "erw" c:optConfig s:rwRuleSeq : conv => `(conv| rw $[$(getConfigItems c)]* (transparency := .default) $s:rwRuleSeq)
+macro "erw" s:rwRuleSeq : conv => `(conv| rw (config := { transparency := .default }) $s)
 
 /-- `args` traverses into all arguments. Synonym for `congr`. -/
 macro "args" : conv => `(conv| congr)
@@ -276,7 +263,7 @@ macro "right" : conv => `(conv| rhs)
 /-- `intro` traverses into binders. Synonym for `ext`. -/
 macro "intro" xs:(ppSpace colGt ident)* : conv => `(conv| ext $xs*)
 
-syntax enterArg := ident <|> argArg
+syntax enterArg := ident <|> ("@"? num)
 
 /-- `enter [arg, ...]` is a compact way to describe a path to a subterm.
 It is a shorthand for other conv tactics as follows:
@@ -285,7 +272,12 @@ It is a shorthand for other conv tactics as follows:
 * `enter [x]` (where `x` is an identifier) is equivalent to `ext x`.
 For example, given the target `f (g a (fun x => x b))`, `enter [1, 2, x, 1]`
 will traverse to the subterm `b`. -/
-syntax (name := enter) "enter" " [" withoutPosition(enterArg,+) "]" : conv
+syntax "enter" " [" withoutPosition(enterArg,+) "]" : conv
+macro_rules
+  | `(conv| enter [$i:num]) => `(conv| arg $i)
+  | `(conv| enter [@$i]) => `(conv| arg @$i)
+  | `(conv| enter [$id:ident]) => `(conv| ext $id)
+  | `(conv| enter [$arg, $args,*]) => `(conv| (enter [$arg]; enter [$args,*]))
 
 /-- The `apply thm` conv tactic is the same as `apply thm` the tactic.
 There are no restrictions on `thm`, but strange results may occur if `thm`

src/Init/Core.lean

@@ -324,6 +324,7 @@ class ForIn' (m : Type u₁ → Type u₂) (ρ : Type u) (α : outParam (Type v)
 
 export ForIn' (forIn')
 
+
 /--
 Auxiliary type used to compile `do` notation. It is used when compiling a do block
 nested inside a combinator like `tryCatch`. It encodes the possible ways the
@@ -861,21 +862,16 @@ theorem Exists.elim {α : Sort u} {p : α → Prop} {b : Prop}
 
 /-! # Decidable -/
 
-@[simp] theorem decide_true (h : Decidable True) : @decide True h = true :=
+theorem decide_true_eq_true (h : Decidable True) : @decide True h = true :=
   match h with
   | isTrue _  => rfl
   | isFalse h => False.elim <| h ⟨⟩
 
-@[simp] theorem decide_false (h : Decidable False) : @decide False h = false :=
+theorem decide_false_eq_false (h : Decidable False) : @decide False h = false :=
   match h with
   | isFalse _ => rfl
   | isTrue h  => False.elim h
 
-set_option linter.missingDocs false in
-@[deprecated decide_true (since := "2024-11-05")] abbrev decide_true_eq_true := decide_true
-set_option linter.missingDocs false in
-@[deprecated decide_false (since := "2024-11-05")] abbrev decide_false_eq_false := decide_false
-
 /-- Similar to `decide`, but uses an explicit instance -/
 @[inline] def toBoolUsing {p : Prop} (d : Decidable p) : Bool :=
   decide (h := d)
@@ -1941,6 +1937,15 @@ instance : Subsingleton (Squash α) where
     apply Quot.sound
     trivial
 
+/-! # Relations -/
+
+/--
+`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
+-/
+class Antisymm {α : Sort u} (r : α → α → Prop) : Prop where
+  /-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
+  antisymm {a b : α} : r a b → r b a → a = b
+
 namespace Lean
 /-! # Kernel reduction hints -/
 
@@ -2116,14 +2121,4 @@ instance : Commutative Or := ⟨fun _ _ => propext or_comm⟩
 instance : Commutative And := ⟨fun _ _ => propext and_comm⟩
 instance : Commutative Iff := ⟨fun _ _ => propext iff_comm⟩
 
-/--
-`Antisymm (·≤·)` says that `(·≤·)` is antisymmetric, that is, `a ≤ b → b ≤ a → a = b`.
--/
-class Antisymm (r : α → α → Prop) : Prop where
-  /-- An antisymmetric relation `(·≤·)` satisfies `a ≤ b → b ≤ a → a = b`. -/
-  antisymm {a b : α} : r a b → r b a → a = b
-
-@[deprecated Antisymm (since := "2024-10-16"), inherit_doc Antisymm]
-abbrev _root_.Antisymm (r : α → α → Prop) : Prop := Std.Antisymm r
-
 end Std

src/Init/Data.lean

@@ -19,7 +19,6 @@ import Init.Data.ByteArray
 import Init.Data.FloatArray
 import Init.Data.Fin
 import Init.Data.UInt
-import Init.Data.SInt
 import Init.Data.Float
 import Init.Data.Option
 import Init.Data.Ord

src/Init/Data/Array.lean

@@ -16,5 +16,3 @@ import Init.Data.Array.Lemmas
 import Init.Data.Array.TakeDrop
 import Init.Data.Array.Bootstrap
 import Init.Data.Array.GetLit
-import Init.Data.Array.MapIdx
-import Init.Data.Array.Set

src/Init/Data/Array/Basic.lean

@@ -12,7 +12,6 @@ import Init.Data.Repr
 import Init.Data.ToString.Basic
 import Init.GetElem
 import Init.Data.List.ToArray
-import Init.Data.Array.Set
 universe u v w
 
 /-! ### Array literal syntax -/
@@ -26,12 +25,9 @@ variable {α : Type u}
 
 namespace Array
 
-@[deprecated toList (since := "2024-10-13")] abbrev data := @toList
-
 /-! ### Preliminary theorems -/
 
-@[simp] theorem size_set (a : Array α) (i : Nat) (v : α) (h : i < a.size) :
-    (set a i v h).size = a.size :=
+@[simp] theorem size_set (a : Array α) (i : Fin a.size) (v : α) : (set a i v).size = a.size :=
   List.length_set ..
 
 @[simp] theorem size_push (a : Array α) (v : α) : (push a v).size = a.size + 1 :=
@@ -82,42 +78,6 @@ theorem ext' {as bs : Array α} (h : as.toList = bs.toList) : as = bs := by
 
 @[simp] theorem size_toArray (as : List α) : as.toArray.size = as.length := by simp [size]
 
-@[simp] theorem getElem_toList {a : Array α} {i : Nat} (h : i < a.size) : a.toList[i] = a[i] := rfl
-
-/-- `a ∈ as` is a predicate which asserts that `a` is in the array `as`. -/
--- NB: This is defined as a structure rather than a plain def so that a lemma
--- like `sizeOf_lt_of_mem` will not apply with no actual arrays around.
-structure Mem (as : Array α) (a : α) : Prop where
-  val : a ∈ as.toList
-
-instance : Membership α (Array α) where
-  mem := Mem
-
-theorem mem_def {a : α} {as : Array α} : a ∈ as ↔ a ∈ as.toList :=
-  ⟨fun | .mk h => h, Array.Mem.mk⟩
-
-@[simp] theorem getElem_mem {l : Array α} {i : Nat} (h : i < l.size) : l[i] ∈ l := by
-  rw [Array.mem_def, ← getElem_toList]
-  apply List.getElem_mem
-
-end Array
-
-namespace List
-
-@[simp] theorem toArray_toList (a : Array α) : a.toList.toArray = a := rfl
-
-@[simp] theorem getElem_toArray {a : List α} {i : Nat} (h : i < a.toArray.size) :
-    a.toArray[i] = a[i]'(by simpa using h) := rfl
-
-@[simp] theorem getElem?_toArray {a : List α} {i : Nat} : a.toArray[i]? = a[i]? := rfl
-
-@[simp] theorem getElem!_toArray [Inhabited α] {a : List α} {i : Nat} :
-    a.toArray[i]! = a[i]! := rfl
-
-end List
-
-namespace Array
-
 @[deprecated toList_toArray (since := "2024-09-09")] abbrev data_toArray := @toList_toArray
 
 @[deprecated Array.toList (since := "2024-09-10")] abbrev Array.data := @Array.toList
@@ -143,7 +103,7 @@ def uget (a : @& Array α) (i : USize) (h : i.toNat < a.size) : α :=
    `fset` may be slightly slower than `uset`. -/
 @[extern "lean_array_uset"]
 def uset (a : Array α) (i : USize) (v : α) (h : i.toNat < a.size) : Array α :=
-  a.set i.toNat v h
+  a.set ⟨i.toNat, h⟩ v
 
 @[extern "lean_array_pop"]
 def pop (a : Array α) : Array α where
@@ -166,14 +126,13 @@ count of 1 when called.
 -/
 @[extern "lean_array_fswap"]
 def swap (a : Array α) (i j : @& Fin a.size) : Array α :=
-  let v₁ := a[i]
-  let v₂ := a[j]
+  let v₁ := a.get i
+  let v₂ := a.get j
   let a'  := a.set i v₂
-  a'.set j v₁ (Nat.lt_of_lt_of_eq j.isLt (size_set a i v₂ _).symm)
+  a'.set (size_set a i v₂ ▸ j) v₁
 
 @[simp] theorem size_swap (a : Array α) (i j : Fin a.size) : (a.swap i j).size = a.size := by
-  show ((a.set i a[j]).set j a[i]
-    (Nat.lt_of_lt_of_eq j.isLt (size_set a i a[j] _).symm)).size = a.size
+  show ((a.set i (a.get j)).set (size_set a i _ ▸ j) (a.get i)).size = a.size
   rw [size_set, size_set]
 
 /--
@@ -238,19 +197,17 @@ def range (n : Nat) : Array Nat :=
 def singleton (v : α) : Array α :=
   mkArray 1 v
 
-def back! [Inhabited α] (a : Array α) : α :=
+def back [Inhabited α] (a : Array α) : α :=
   a.get! (a.size - 1)
 
-@[deprecated back! (since := "2024-10-31")] abbrev back := @back!
-
 def get? (a : Array α) (i : Nat) : Option α :=
   if h : i < a.size then some a[i] else none
 
 def back? (a : Array α) : Option α :=
-  a[a.size - 1]?
+  a.get? (a.size - 1)
 
 @[inline] def swapAt (a : Array α) (i : Fin a.size) (v : α) : α × Array α :=
-  let e := a[i]
+  let e := a.get i
   let a := a.set i v
   (e, a)
 
@@ -262,34 +219,33 @@ def swapAt! (a : Array α) (i : Nat) (v : α) : α × Array α :=
     have : Inhabited (α × Array α) := ⟨(v, a)⟩
     panic! ("index " ++ toString i ++ " out of bounds")
 
-/-- `take a n` returns the first `n` elements of `a`. -/
-def take (a : Array α) (n : Nat) : Array α :=
+def shrink (a : Array α) (n : Nat) : Array α :=
   let rec loop
     | 0,   a => a
     | n+1, a => loop n a.pop
   loop (a.size - n) a
 
-@[deprecated take (since := "2024-10-22")] abbrev shrink := @take
-
 @[inline]
 unsafe def modifyMUnsafe [Monad m] (a : Array α) (i : Nat) (f : α → m α) : m (Array α) := do
   if h : i < a.size then
-    let v                := a[i]
+    let idx : Fin a.size := ⟨i, h⟩
+    let v                := a.get idx
     -- Replace a[i] by `box(0)`.  This ensures that `v` remains unshared if possible.
     -- Note: we assume that arrays have a uniform representation irrespective
     -- of the element type, and that it is valid to store `box(0)` in any array.
-    let a'               := a.set i (unsafeCast ())
+    let a'               := a.set idx (unsafeCast ())
     let v ← f v
-    pure <| a'.set i v (Nat.lt_of_lt_of_eq h (size_set a ..).symm)
+    pure <| a'.set (size_set a .. ▸ idx) v
   else
     pure a
 
 @[implemented_by modifyMUnsafe]
 def modifyM [Monad m] (a : Array α) (i : Nat) (f : α → m α) : m (Array α) := do
   if h : i < a.size then
-    let v   := a[i]
+    let idx := ⟨i, h⟩
+    let v   := a.get idx
     let v ← f v
-    pure <| a.set i v
+    pure <| a.set idx v
   else
     pure a
 
@@ -305,21 +261,21 @@ def modifyOp (self : Array α) (idx : Nat) (f : α → α) : Array α :=
   We claim this unsafe implementation is correct because an array cannot have more than `usizeSz` elements in our runtime.
 
   This kind of low level trick can be removed with a little bit of compiler support. For example, if the compiler simplifies `as.size < usizeSz` to true. -/
-@[inline] unsafe def forIn'Unsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (b : β) (f : (a : α) → a ∈ as → β → m (ForInStep β)) : m β :=
+@[inline] unsafe def forInUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (b : β) (f : α → β → m (ForInStep β)) : m β :=
   let sz := as.usize
   let rec @[specialize] loop (i : USize) (b : β) : m β := do
     if i < sz then
       let a := as.uget i lcProof
-      match (← f a lcProof b) with
+      match (← f a b) with
       | ForInStep.done  b => pure b
       | ForInStep.yield b => loop (i+1) b
     else
       pure b
   loop 0 b
 
-/-- Reference implementation for `forIn'` -/
-@[implemented_by Array.forIn'Unsafe]
-protected def forIn' {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (b : β) (f : (a : α) → a ∈ as → β → m (ForInStep β)) : m β :=
+/-- Reference implementation for `forIn` -/
+@[implemented_by Array.forInUnsafe]
+protected def forIn {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (b : β) (f : α → β → m (ForInStep β)) : m β :=
   let rec loop (i : Nat) (h : i ≤ as.size) (b : β) : m β := do
     match i, h with
     | 0,   _ => pure b
@@ -327,17 +283,15 @@ protected def forIn' {α : Type u} {β : Type v} {m : Type v → Type w} [Monad
       have h' : i < as.size            := Nat.lt_of_lt_of_le (Nat.lt_succ_self i) h
       have : as.size - 1 < as.size     := Nat.sub_lt (Nat.zero_lt_of_lt h') (by decide)
       have : as.size - 1 - i < as.size := Nat.lt_of_le_of_lt (Nat.sub_le (as.size - 1) i) this
-      match (← f as[as.size - 1 - i] (getElem_mem this) b) with
+      match (← f as[as.size - 1 - i] b) with
       | ForInStep.done b  => pure b
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
 
-instance : ForIn' m (Array α) α inferInstance where
-  forIn' := Array.forIn'
+instance : ForIn m (Array α) α where
+  forIn := Array.forIn
 
--- No separate `ForIn` instance is required because it can be derived from `ForIn'`.
-
-/-- See comment at `forIn'Unsafe` -/
+/-- See comment at `forInUnsafe` -/
 @[inline]
 unsafe def foldlMUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : β → α → m β) (init : β) (as : Array α) (start := 0) (stop := as.size) : m β :=
   let rec @[specialize] fold (i : USize) (stop : USize) (b : β) : m β := do
@@ -372,7 +326,7 @@ def foldlM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : β
   else
     fold as.size (Nat.le_refl _)
 
-/-- See comment at `forIn'Unsafe` -/
+/-- See comment at `forInUnsafe` -/
 @[inline]
 unsafe def foldrMUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α → β → m β) (init : β) (as : Array α) (start := as.size) (stop := 0) : m β :=
   let rec @[specialize] fold (i : USize) (stop : USize) (b : β) : m β := do
@@ -411,7 +365,7 @@ def foldrM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α
   else
     pure init
 
-/-- See comment at `forIn'Unsafe` -/
+/-- See comment at `forInUnsafe` -/
 @[inline]
 unsafe def mapMUnsafe {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α → m β) (as : Array α) : m (Array β) :=
   let sz := as.usize
@@ -442,29 +396,22 @@ def mapM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α
   decreasing_by simp_wf; decreasing_trivial_pre_omega
   map 0 (mkEmpty as.size)
 
-@[deprecated mapM (since := "2024-11-11")] abbrev sequenceMap := @mapM
-
-/-- Variant of `mapIdxM` which receives the index as a `Fin as.size`. -/
 @[inline]
-def mapFinIdxM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m]
-    (as : Array α) (f : Fin as.size → α → m β) : m (Array β) :=
+def mapIdxM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (f : Fin as.size → α → m β) : m (Array β) :=
   let rec @[specialize] map (i : Nat) (j : Nat) (inv : i + j = as.size) (bs : Array β) : m (Array β) := do
     match i, inv with
     | 0,    _  => pure bs
     | i+1, inv =>
-      have j_lt : j < as.size := by
+      have : j < as.size := by
         rw [← inv, Nat.add_assoc, Nat.add_comm 1 j, Nat.add_comm]
         apply Nat.le_add_right
+      let idx : Fin as.size := ⟨j, this⟩
       have : i + (j + 1) = as.size := by rw [← inv, Nat.add_comm j 1, Nat.add_assoc]
-      map i (j+1) this (bs.push (← f ⟨j, j_lt⟩ (as.get j j_lt)))
+      map i (j+1) this (bs.push (← f idx (as.get idx)))
   map as.size 0 rfl (mkEmpty as.size)
 
 @[inline]
-def mapIdxM {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : Nat → α → m β) (as : Array α) : m (Array β) :=
-  as.mapFinIdxM fun i a => f i a
-
-@[inline]
-def findSomeM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α → m (Option β)) (as : Array α) : m (Option β) := do
+def findSomeM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (f : α → m (Option β)) : m (Option β) := do
   for a in as do
     match (← f a) with
     | some b => return b
@@ -472,14 +419,14 @@ def findSomeM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f
   return none
 
 @[inline]
-def findM? {α : Type} {m : Type → Type} [Monad m] (p : α → m Bool) (as : Array α) : m (Option α) := do
+def findM? {α : Type} {m : Type → Type} [Monad m] (as : Array α) (p : α → m Bool) : m (Option α) := do
   for a in as do
     if (← p a) then
       return a
   return none
 
 @[inline]
-def findIdxM? [Monad m] (p : α → m Bool) (as : Array α) : m (Option Nat) := do
+def findIdxM? [Monad m] (as : Array α) (p : α → m Bool) : m (Option Nat) := do
   let mut i := 0
   for a in as do
     if (← p a) then
@@ -531,7 +478,7 @@ def allM {α : Type u} {m : Type → Type w} [Monad m] (p : α → m Bool) (as :
   return !(← as.anyM (start := start) (stop := stop) fun v => return !(← p v))
 
 @[inline]
-def findSomeRevM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (f : α → m (Option β)) (as : Array α) : m (Option β) :=
+def findSomeRevM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : Array α) (f : α → m (Option β)) : m (Option β) :=
   let rec @[specialize] find : (i : Nat) → i ≤ as.size → m (Option β)
     | 0,   _ => pure none
     | i+1, h => do
@@ -545,7 +492,7 @@ def findSomeRevM? {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m]
   find as.size (Nat.le_refl _)
 
 @[inline]
-def findRevM? {α : Type} {m : Type → Type w} [Monad m] (p : α → m Bool) (as : Array α) : m (Option α) :=
+def findRevM? {α : Type} {m : Type → Type w} [Monad m] (as : Array α) (p : α → m Bool) : m (Option α) :=
   as.findSomeRevM? fun a => return if (← p a) then some a else none
 
 @[inline]
@@ -568,13 +515,8 @@ def foldr {α : Type u} {β : Type v} (f : α → β → β) (init : β) (as : A
 def map {α : Type u} {β : Type v} (f : α → β) (as : Array α) : Array β :=
   Id.run <| as.mapM f
 
-/-- Variant of `mapIdx` which receives the index as a `Fin as.size`. -/
 @[inline]
-def mapFinIdx {α : Type u} {β : Type v} (as : Array α) (f : Fin as.size → α → β) : Array β :=
-  Id.run <| as.mapFinIdxM f
-
-@[inline]
-def mapIdx {α : Type u} {β : Type v} (f : Nat → α → β) (as : Array α) : Array β :=
+def mapIdx {α : Type u} {β : Type v} (as : Array α) (f : Fin as.size → α → β) : Array β :=
   Id.run <| as.mapIdxM f
 
 /-- Turns `#[a, b]` into `#[(a, 0), (b, 1)]`. -/
@@ -582,29 +524,29 @@ def zipWithIndex (arr : Array α) : Array (α × Nat) :=
   arr.mapIdx fun i a => (a, i)
 
 @[inline]
-def find? {α : Type} (p : α → Bool) (as : Array α) : Option α :=
+def find? {α : Type} (as : Array α) (p : α → Bool) : Option α :=
   Id.run <| as.findM? p
 
 @[inline]
-def findSome? {α : Type u} {β : Type v} (f : α → Option β) (as : Array α) : Option β :=
+def findSome? {α : Type u} {β : Type v} (as : Array α) (f : α → Option β) : Option β :=
   Id.run <| as.findSomeM? f
 
 @[inline]
-def findSome! {α : Type u} {β : Type v} [Inhabited β] (f : α → Option β) (a : Array α) : β :=
-  match a.findSome? f with
+def findSome! {α : Type u} {β : Type v} [Inhabited β] (a : Array α) (f : α → Option β) : β :=
+  match findSome? a f with
   | some b => b
   | none   => panic! "failed to find element"
 
 @[inline]
-def findSomeRev? {α : Type u} {β : Type v} (f : α → Option β) (as : Array α) : Option β :=
+def findSomeRev? {α : Type u} {β : Type v} (as : Array α) (f : α → Option β) : Option β :=
   Id.run <| as.findSomeRevM? f
 
 @[inline]
-def findRev? {α : Type} (p : α → Bool) (as : Array α) : Option α :=
+def findRev? {α : Type} (as : Array α) (p : α → Bool) : Option α :=
   Id.run <| as.findRevM? p
 
 @[inline]
-def findIdx? {α : Type u} (p : α → Bool) (as : Array α) : Option Nat :=
+def findIdx? {α : Type u} (as : Array α) (p : α → Bool) : Option Nat :=
   let rec @[semireducible] -- This is otherwise irreducible because it uses well-founded recursion.
   loop (j : Nat) :=
     if h : j < as.size then
@@ -619,7 +561,8 @@ def getIdx? [BEq α] (a : Array α) (v : α) : Option Nat :=
 @[semireducible] -- This is otherwise irreducible because it uses well-founded recursion.
 def indexOfAux [BEq α] (a : Array α) (v : α) (i : Nat) : Option (Fin a.size) :=
   if h : i < a.size then
-    if a[i] == v then some ⟨i, h⟩
+    let idx : Fin a.size := ⟨i, h⟩;
+    if a.get idx == v then some idx
     else indexOfAux a v (i+1)
   else none
 decreasing_by simp_wf; decreasing_trivial_pre_omega
@@ -667,7 +610,7 @@ instance : HAppend (Array α) (List α) (Array α) := ⟨Array.appendList⟩
 def flatMapM [Monad m] (f : α → m (Array β)) (as : Array α) : m (Array β) :=
   as.foldlM (init := empty) fun bs a => do return bs ++ (← f a)
 
-@[deprecated flatMapM (since := "2024-10-16")] abbrev concatMapM := @flatMapM
+@[deprecated concatMapM (since := "2024-10-16")] abbrev concatMapM := @flatMapM
 
 @[inline]
 def flatMap (f : α → Array β) (as : Array α) : Array β :=
@@ -744,7 +687,7 @@ where
 @[semireducible] -- This is otherwise irreducible because it uses well-founded recursion.
 def popWhile (p : α → Bool) (as : Array α) : Array α :=
   if h : as.size > 0 then
-    if p (as[as.size - 1]'(Nat.sub_lt h (by decide))) then
+    if p (as.get ⟨as.size - 1, Nat.sub_lt h (by decide)⟩) then
       popWhile p as.pop
     else
       as
@@ -756,7 +699,7 @@ def takeWhile (p : α → Bool) (as : Array α) : Array α :=
   let rec @[semireducible] -- This is otherwise irreducible because it uses well-founded recursion.
   go (i : Nat) (r : Array α) : Array α :=
     if h : i < as.size then
-      let a := as[i]
+      let a := as.get ⟨i, h⟩
       if p a then
         go (i+1) (r.push a)
       else
@@ -868,22 +811,15 @@ def zip (as : Array α) (bs : Array β) : Array (α × β) :=
 def unzip (as : Array (α × β)) : Array α × Array β :=
   as.foldl (init := (#[], #[])) fun (as, bs) (a, b) => (as.push a, bs.push b)
 
-@[deprecated partition (since := "2024-11-06")]
 def split (as : Array α) (p : α → Bool) : Array α × Array α :=
   as.foldl (init := (#[], #[])) fun (as, bs) a =>
     if p a then (as.push a, bs) else (as, bs.push a)
 
 /-! ## Auxiliary functions used in metaprogramming.
 
-We do not currently intend to provide verification theorems for these functions.
+We do not intend to provide verification theorems for these functions.
 -/
 
-/- ### reduceOption -/
-
-/-- Drop `none`s from a Array, and replace each remaining `some a` with `a`. -/
-@[inline] def reduceOption (as : Array (Option α)) : Array α :=
-  as.filterMap id
-
 /-! ### eraseReps -/
 
 /--

src/Init/Data/Array/BasicAux.lean

@@ -60,7 +60,7 @@ where
       if ptrEq a b then
         go (i+1) as
       else
-        go (i+1) (as.set i b h)
+        go (i+1) (as.set ⟨i, h⟩ b)
     else
       return as
 

src/Init/Data/Array/BinSearch.lean

@@ -69,8 +69,8 @@ namespace Array
   if as.isEmpty then do let v ← add (); pure <| as.push v
   else if lt k (as.get! 0) then do let v ← add (); pure <| as.insertAt! 0 v
   else if !lt (as.get! 0) k then as.modifyM 0 <| merge
-  else if lt as.back! k then do let v ← add (); pure <| as.push v
-  else if !lt k as.back! then as.modifyM (as.size - 1) <| merge
+  else if lt as.back k then do let v ← add (); pure <| as.push v
+  else if !lt k as.back then as.modifyM (as.size - 1) <| merge
   else binInsertAux lt merge add as k 0 (as.size - 1)
 
 @[inline] def binInsert {α : Type u} (lt : α → α → Bool) (as : Array α) (k : α) : Array α :=

src/Init/Data/Array/Bootstrap.lean

@@ -23,7 +23,7 @@ theorem foldlM_eq_foldlM_toList.aux [Monad m]
   · cases Nat.not_le_of_gt ‹_› (Nat.zero_add _ ▸ H)
   · rename_i i; rw [Nat.succ_add] at H
     simp [foldlM_eq_foldlM_toList.aux f arr i (j+1) H]
-    rw (occs := .pos [2]) [← List.getElem_cons_drop_succ_eq_drop ‹_›]
+    rw (config := {occs := .pos [2]}) [← List.get_drop_eq_drop _ _ ‹_›]
     rfl
   · rw [List.drop_of_length_le (Nat.ge_of_not_lt ‹_›)]; rfl
 
@@ -42,7 +42,7 @@ theorem foldrM_eq_reverse_foldlM_toList.aux [Monad m]
   unfold foldrM.fold
   match i with
   | 0 => simp [List.foldlM, List.take]
-  | i+1 => rw [← List.take_concat_get _ _ h]; simp [← (aux f arr · i)]
+  | i+1 => rw [← List.take_concat_get _ _ h]; simp [← (aux f arr · i)]; rfl
 
 theorem foldrM_eq_reverse_foldlM_toList [Monad m] (f : α → β → m β) (init : β) (arr : Array α) :
     arr.foldrM f init = arr.toList.reverse.foldlM (fun x y => f y x) init := by
@@ -79,17 +79,6 @@ theorem foldr_eq_foldr_toList (f : α → β → β) (init : β) (arr : Array α
   rw [foldl_eq_foldl_toList]
   induction arr'.toList generalizing arr <;> simp [*]
 
-@[simp] theorem toList_empty : (#[] : Array α).toList = [] := rfl
-
-@[simp] theorem append_nil (as : Array α) : as ++ #[] = as := by
-  apply ext'; simp only [toList_append, toList_empty, List.append_nil]
-
-@[simp] theorem nil_append (as : Array α) : #[] ++ as = as := by
-  apply ext'; simp only [toList_append, toList_empty, List.nil_append]
-
-@[simp] theorem append_assoc (as bs cs : Array α) : as ++ bs ++ cs = as ++ (bs ++ cs) := by
-  apply ext'; simp only [toList_append, List.append_assoc]
-
 @[simp] theorem appendList_eq_append
     (arr : Array α) (l : List α) : arr.appendList l = arr ++ l := rfl
 

src/Init/Data/Array/DecidableEq.lean

@@ -6,16 +6,14 @@ Authors: Leonardo de Moura
 prelude
 import Init.Data.Array.Basic
 import Init.Data.BEq
-import Init.Data.Nat.Lemmas
-import Init.Data.List.Nat.BEq
 import Init.ByCases
 
 namespace Array
 
 theorem rel_of_isEqvAux
-    {r : α → α → Bool} {a b : Array α} (hsz : a.size = b.size) {i : Nat} (hi : i ≤ a.size)
+    (r : α → α → Bool) (a b : Array α) (hsz : a.size = b.size) (i : Nat) (hi : i ≤ a.size)
     (heqv : Array.isEqvAux a b hsz r i hi)
-    {j : Nat} (hj : j < i) : r (a[j]'(Nat.lt_of_lt_of_le hj hi)) (b[j]'(Nat.lt_of_lt_of_le hj (hsz ▸ hi))) := by
+    (j : Nat) (hj : j < i) : r (a[j]'(Nat.lt_of_lt_of_le hj hi)) (b[j]'(Nat.lt_of_lt_of_le hj (hsz ▸ hi))) := by
   induction i with
   | zero => contradiction
   | succ i ih =>
@@ -28,46 +26,15 @@ theorem rel_of_isEqvAux
       subst hj'
       exact heqv.left
 
-theorem isEqvAux_of_rel {r : α → α → Bool} {a b : Array α} (hsz : a.size = b.size) {i : Nat} (hi : i ≤ a.size)
-    (w : ∀ j, (hj : j < i) → r (a[j]'(Nat.lt_of_lt_of_le hj hi)) (b[j]'(Nat.lt_of_lt_of_le hj (hsz ▸ hi)))) : Array.isEqvAux a b hsz r i hi := by
-  induction i with
-  | zero => simp [Array.isEqvAux]
-  | succ i ih =>
-    simp only [isEqvAux, Bool.and_eq_true]
-    exact ⟨w i (Nat.lt_add_one i), ih _ fun j hj => w j (Nat.lt_add_right 1 hj)⟩
-
-theorem rel_of_isEqv {r : α → α → Bool} {a b : Array α} :
+theorem rel_of_isEqv (r : α → α → Bool) (a b : Array α) :
     Array.isEqv a b r → ∃ h : a.size = b.size, ∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h')) := by
   simp only [isEqv]
   split <;> rename_i h
-  · exact fun h' => ⟨h, fun i => rel_of_isEqvAux h (Nat.le_refl ..) h'⟩
+  · exact fun h' => ⟨h, rel_of_isEqvAux r a b h a.size (Nat.le_refl ..) h'⟩
   · intro; contradiction
 
-theorem isEqv_iff_rel (a b : Array α) (r) :
-    Array.isEqv a b r ↔ ∃ h : a.size = b.size, ∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h')) :=
-  ⟨rel_of_isEqv, fun ⟨h, w⟩ => by
-    simp only [isEqv, ← h, ↓reduceDIte]
-    exact isEqvAux_of_rel h (by simp [h]) w⟩
-
-theorem isEqv_eq_decide (a b : Array α) (r) :
-    Array.isEqv a b r =
-      if h : a.size = b.size then decide (∀ (i : Nat) (h' : i < a.size), r (a[i]) (b[i]'(h ▸ h'))) else false := by
-  by_cases h : Array.isEqv a b r
-  · simp only [h, Bool.true_eq]
-    simp only [isEqv_iff_rel] at h
-    obtain ⟨h, w⟩ := h
-    simp [h, w]
-  · let h' := h
-    simp only [Bool.not_eq_true] at h
-    simp only [h, Bool.false_eq, dite_eq_right_iff, decide_eq_false_iff_not, Classical.not_forall,
-      Bool.not_eq_true]
-    simpa [isEqv_iff_rel] using h'
-
-@[simp] theorem isEqv_toList [BEq α] (a b : Array α) : (a.toList.isEqv b.toList r) = (a.isEqv b r) := by
-  simp [isEqv_eq_decide, List.isEqv_eq_decide]
-
 theorem eq_of_isEqv [DecidableEq α] (a b : Array α) (h : Array.isEqv a b (fun x y => x = y)) : a = b := by
-  have ⟨h, h'⟩ := rel_of_isEqv h
+  have ⟨h, h'⟩ := rel_of_isEqv (fun x y => x = y) a b h
   exact ext _ _ h (fun i lt _ => by simpa using h' i lt)
 
 theorem isEqvAux_self (r : α → α → Bool) (hr : ∀ a, r a a) (a : Array α) (i : Nat) (h : i ≤ a.size) :
@@ -89,22 +56,4 @@ instance [DecidableEq α] : DecidableEq (Array α) :=
     | true  => isTrue (eq_of_isEqv a b h)
     | false => isFalse fun h' => by subst h'; rw [isEqv_self] at h; contradiction
 
-theorem beq_eq_decide [BEq α] (a b : Array α) :
-    (a == b) = if h : a.size = b.size then
-      decide (∀ (i : Nat) (h' : i < a.size), a[i] == b[i]'(h ▸ h')) else false := by
-  simp [BEq.beq, isEqv_eq_decide]
-
-@[simp] theorem beq_toList [BEq α] (a b : Array α) : (a.toList == b.toList) = (a == b) := by
-  simp [beq_eq_decide, List.beq_eq_decide]
-
 end Array
-
-namespace List
-
-@[simp] theorem isEqv_toArray [BEq α] (a b : List α) : (a.toArray.isEqv b.toArray r) = (a.isEqv b r) := by
-  simp [isEqv_eq_decide, Array.isEqv_eq_decide]
-
-@[simp] theorem beq_toArray [BEq α] (a b : List α) : (a.toArray == b.toArray) = (a == b) := by
-  simp [beq_eq_decide, Array.beq_eq_decide]
-
-end List

src/Init/Data/Array/GetLit.lean

@@ -41,6 +41,6 @@ where
   getLit_eq (as : Array α) (i : Nat) (h₁ : as.size = n) (h₂ : i < n) : as.getLit i h₁ h₂ = getElem as.toList i ((id (α := as.toList.length = n) h₁) ▸ h₂) :=
     rfl
   go (i : Nat) (hi : i ≤ as.size) : toListLitAux as n hsz i hi (as.toList.drop i) = as.toList := by
-    induction i <;> simp only [List.drop, toListLitAux, getLit_eq, List.getElem_cons_drop_succ_eq_drop, *]
+    induction i <;> simp [getLit_eq, List.get_drop_eq_drop, toListLitAux, List.drop, *]
 
 end Array

src/Init/Data/Array/MapIdx.lean

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

src/Init/Data/Array/Mem.lean

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

src/Init/Data/Array/Set.lean

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

src/Init/Data/Array/Subarray.lean

@@ -48,7 +48,7 @@ instance : GetElem (Subarray α) Nat α fun xs i => i < xs.size where
   getElem xs i h := xs.get ⟨i, h⟩
 
 @[inline] def getD (s : Subarray α) (i : Nat) (v₀ : α) : α :=
-  if h : i < s.size then s[i] else v₀
+  if h : i < s.size then s.get ⟨i, h⟩ else v₀
 
 abbrev get! [Inhabited α] (s : Subarray α) (i : Nat) : α :=
   getD s i default

src/Init/Data/BitVec/Basic.lean

@@ -634,16 +634,6 @@ def twoPow (w : Nat) (i : Nat) : BitVec w := 1#w <<< i
 
 end bitwise
 
-/-- Compute a hash of a bitvector, combining 64-bit words using `mixHash`. -/
-def hash (bv : BitVec n) : UInt64 :=
-  if n ≤ 64 then
-    bv.toFin.val.toUInt64
-  else
-    mixHash (bv.toFin.val.toUInt64) (hash ((bv >>> 64).setWidth (n - 64)))
-
-instance : Hashable (BitVec n) where
-  hash := hash
-
 section normalization_eqs
 /-! We add simp-lemmas that rewrite bitvector operations into the equivalent notation -/
 @[simp] theorem append_eq (x : BitVec w) (y : BitVec v)   : BitVec.append x y = x ++ y        := rfl

src/Init/Data/BitVec/Bitblast.lean

@@ -76,7 +76,7 @@ to prove the correctness of the circuit that is built by `bv_decide`.
 def blastMul (aig : AIG BVBit) (input : AIG.BinaryRefVec aig w) : AIG.RefVecEntry BVBit w
 theorem denote_blastMul (aig : AIG BVBit) (lhs rhs : BitVec w) (assign : Assignment) :
    ...
-   ⟦(blastMul aig input).aig, (blastMul aig input).vec[idx], assign.toAIGAssignment⟧
+   ⟦(blastMul aig input).aig, (blastMul aig input).vec.get idx hidx, assign.toAIGAssignment⟧
      =
    (lhs * rhs).getLsbD idx
 ```
@@ -174,30 +174,6 @@ theorem carry_succ (i : Nat) (x y : BitVec w) (c : Bool) :
     exact mod_two_pow_add_mod_two_pow_add_bool_lt_two_pow_succ ..
   cases x.toNat.testBit i <;> cases y.toNat.testBit i <;> (simp; omega)
 
-theorem carry_succ_one (i : Nat) (x : BitVec w) (h : 0 < w) :
-    carry (i+1) x (1#w) false = decide (∀ j ≤ i, x.getLsbD j = true) := by
-  induction i with
-  | zero => simp [carry_succ, h]
-  | succ i ih =>
-    rw [carry_succ, ih]
-    simp only [getLsbD_one, add_one_ne_zero, decide_false, Bool.and_false, atLeastTwo_false_mid]
-    cases hx : x.getLsbD (i+1)
-    case false =>
-      have : ∃ j ≤ i + 1, x.getLsbD j = false :=
-        ⟨i+1, by omega, hx⟩
-      simpa
-    case true =>
-      suffices
-          (∀ (j : Nat), j ≤ i → x.getLsbD j = true)
-          ↔ (∀ (j : Nat), j ≤ i + 1 → x.getLsbD j = true) by
-        simpa
-      constructor
-      · intro h j hj
-        rcases Nat.le_or_eq_of_le_succ hj with (hj' | rfl)
-        · apply h; assumption
-        · exact hx
-      · intro h j hj; apply h; omega
-
 /--
 If `x &&& y = 0`, then the carry bit `(x + y + 0)` is always `false` for any index `i`.
 Intuitively, this is because a carry is only produced when at least two of `x`, `y`, and the
@@ -249,7 +225,7 @@ theorem getLsbD_add_add_bool {i : Nat} (i_lt : i < w) (x y : BitVec w) (c : Bool
     [ Nat.testBit_mod_two_pow,
       Nat.testBit_mul_two_pow_add_eq,
       i_lt,
-      decide_true,
+      decide_True,
       Bool.true_and,
       Nat.add_assoc,
       Nat.add_left_comm (_%_) (_ * _) _,
@@ -376,117 +352,6 @@ theorem bit_neg_eq_neg (x : BitVec w) : -x = (adc (((iunfoldr (fun (i : Fin w) c
     simp [← sub_toAdd, BitVec.sub_add_cancel]
   · simp [bit_not_testBit x _]
 
-/--
-Remember that negating a bitvector is equal to incrementing the complement
-by one, i.e., `-x = ~~~x + 1`. See also `neg_eq_not_add`.
-
-This computation has two crucial properties:
-- The least significant bit of `-x` is the same as the least significant bit of `x`, and
-- The `i+1`-th least significant bit of `-x` is the complement of the `i+1`-th bit of `x`, unless
-  all of the preceding bits are `false`, in which case the bit is equal to the `i+1`-th bit of `x`
--/
-theorem getLsbD_neg {i : Nat} {x : BitVec w} :
-    getLsbD (-x) i =
-      (getLsbD x i ^^ decide (i < w) && decide (∃ j < i, getLsbD x j = true)) := by
-  rw [neg_eq_not_add]
-  by_cases hi : i < 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]
-    cases i with
-    | zero =>
-      have carry_zero : carry 0 ?x ?y false = false := by
-        simp [carry]; omega
-      simp [hi, carry_zero]
-    | succ =>
-      rw [carry_succ_one _ _ (by omega), ← Bool.xor_not, ← decide_not]
-      simp only [add_one_ne_zero, decide_false, getLsbD_not, and_eq_true, decide_eq_true_eq,
-        not_eq_eq_eq_not, Bool.not_true, false_bne, not_exists, _root_.not_and, not_eq_true,
-        bne_left_inj, decide_eq_decide]
-      constructor
-      · 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_ge _ _ h_ge, h_ge, hi]
-
-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]
-  by_cases hi : i < w
-  case neg =>
-    simp [hi]; omega
-  case pos =>
-    have h₁ : w - 1 - i < w := by omega
-    simp only [hi, decide_true, h₁, Bool.true_and, Bool.bne_left_inj, decide_eq_decide]
-    constructor
-    · rintro ⟨j, hj, h⟩
-      refine ⟨w - 1 - j, by omega, by omega, by omega, _root_.cast ?_ h⟩
-      congr; omega
-    · rintro ⟨j, hj₁, hj₂, -, h⟩
-      exact ⟨w - 1 - j, by omega, h⟩
-
-theorem msb_neg {w : Nat} {x : BitVec w} :
-    (-x).msb = ((x != 0#w && x != intMin w) ^^ x.msb) := by
-  simp only [BitVec.msb, getMsbD_neg]
-  by_cases hmin : x = intMin _
-  case pos =>
-    have : (∃ j, j < w ∧ 0 < j ∧ 0 < w ∧ j = 0) ↔ False := by
-      simp; omega
-    simp [hmin, getMsbD_intMin, this]
-  case neg =>
-    by_cases hzero : x = 0#w
-    case pos => simp [hzero]
-    case neg =>
-      have w_pos : 0 < w := by
-        cases w
-        · rw [@of_length_zero x] at hzero
-          contradiction
-        · omega
-      suffices ∃ j, j < w ∧ 0 < j ∧ x.getMsbD j = true
-        by simp [show x != 0#w by simpa, show x != intMin w by simpa, this]
-      false_or_by_contra
-      rename_i getMsbD_x
-      simp only [not_exists, _root_.not_and, not_eq_true] at getMsbD_x
-      /- `getMsbD` says that all bits except the msb are `false` -/
-      cases hmsb : x.msb
-      case true =>
-        apply hmin
-        apply eq_of_getMsbD_eq
-        rintro ⟨i, hi⟩
-        simp only [getMsbD_intMin, w_pos, decide_true, Bool.true_and]
-        cases i
-        case zero => exact hmsb
-        case succ => exact getMsbD_x _ hi (by omega)
-      case false =>
-        apply hzero
-        apply eq_of_getMsbD_eq
-        rintro ⟨i, hi⟩
-        simp only [getMsbD_zero]
-        cases i
-        case zero => exact hmsb
-        case succ => exact getMsbD_x _ hi (by omega)
-
-/-! ### 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]
-  by_cases h₀ : 0 < w
-  · by_cases h₁ : x = intMin w
-    · simp [h₁, msb_intMin]
-    · simp only [neg_eq, h₁, decide_false]
-      by_cases h₂ : x.msb
-      · simp [h₂, msb_neg]
-        and_intros
-        · by_cases h₃ : x = 0#w
-          · simp [h₃] at h₂
-          · simp [h₃]
-        · simp [h₁]
-      · simp [h₂]
-  · simp [BitVec.msb, show w = 0 by omega]
-
 /-! ### Inequalities (le / lt) -/
 
 theorem ult_eq_not_carry (x y : BitVec w) : x.ult y = !carry w x (~~~y) true := by
@@ -566,18 +431,18 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_add_twoPow (x : BitVec w) (i
       setWidth w (x.setWidth i) + (x &&& twoPow w i) := by
   rw [add_eq_or_of_and_eq_zero]
   · ext k
-    simp only [getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and, getLsbD_or, getLsbD_and]
+    simp only [getLsbD_setWidth, Fin.is_lt, decide_True, Bool.true_and, getLsbD_or, getLsbD_and]
     by_cases hik : i = k
     · subst hik
       simp
-    · simp only [getLsbD_twoPow, hik, decide_false, Bool.and_false, Bool.or_false]
+    · simp only [getLsbD_twoPow, hik, decide_False, Bool.and_false, Bool.or_false]
       by_cases hik' : k < (i + 1)
       · have hik'' : k < i := by omega
         simp [hik', hik'']
       · have hik'' : ¬ (k < i) := by omega
         simp [hik', hik'']
   · ext k
-    simp only [and_twoPow, getLsbD_and, getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and,
+    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]
     by_cases hi : x.getLsbD i <;> simp [hi] <;> omega
 
@@ -1092,8 +957,8 @@ def sshiftRightRec (x : BitVec w₁) (y : BitVec w₂) (n : Nat) : BitVec w₁ :
 
 @[simp]
 theorem sshiftRightRec_zero_eq (x : BitVec w₁) (y : BitVec w₂) :
-    sshiftRightRec x y 0 = x.sshiftRight' (y &&& twoPow w₂ 0) := by
-  simp only [sshiftRightRec]
+    sshiftRightRec x y 0 = x.sshiftRight' (y &&& 1#w₂) := by
+  simp only [sshiftRightRec, twoPow_zero]
 
 @[simp]
 theorem sshiftRightRec_succ_eq (x : BitVec w₁) (y : BitVec w₂) (n : Nat) :

src/Init/Data/BitVec/Folds.lean

@@ -65,7 +65,7 @@ theorem iunfoldr_getLsbD' {f : Fin w → α → α × Bool} (state : Nat → α)
     intro
     apply And.intro
     · intro i
-      have := Fin.pos i
+      have := Fin.size_pos i
       contradiction
     · rfl
   case step =>

src/Init/Data/BitVec/Lemmas.lean

@@ -123,7 +123,7 @@ theorem getMsbD_eq_getLsbD (x : BitVec w) (i : Nat) : x.getMsbD i = (decide (i <
 theorem getLsbD_eq_getMsbD (x : BitVec w) (i : Nat) : x.getLsbD i = (decide (i < w) && x.getMsbD (w - 1 - i)) := by
   rw [getMsbD]
   by_cases h₁ : i < w <;> by_cases h₂ : w - 1 - i < w <;>
-    simp only [h₁, h₂] <;> simp only [decide_true, decide_false, Bool.false_and, Bool.and_false, Bool.true_and, Bool.and_true]
+    simp only [h₁, h₂] <;> simp only [decide_True, decide_False, Bool.false_and, Bool.and_false, Bool.true_and, Bool.and_true]
   · congr
     omega
   all_goals
@@ -316,12 +316,6 @@ theorem getLsbD_ofNat (n : Nat) (x : Nat) (i : Nat) :
   simp [Nat.sub_sub_eq_min, Nat.min_eq_right]
   omega
 
-@[simp] theorem sub_add_bmod_cancel {x y : BitVec w} :
-    ((((2 ^ w : Nat) - y.toNat) : Int) + x.toNat).bmod (2 ^ w) =
-      ((x.toNat : Int) - y.toNat).bmod (2 ^ w) := by
-  rw [Int.sub_eq_add_neg, Int.add_assoc, Int.add_comm, Int.bmod_add_cancel, Int.add_comm,
-    Int.sub_eq_add_neg]
-
 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_of_le_right (by trivial : 0 < 2) le)
 
@@ -386,7 +380,7 @@ theorem msb_eq_getLsbD_last (x : BitVec w) :
     · simp [Nat.div_eq_of_lt h, h]
     · simp only [h]
       rw [Nat.div_eq_sub_div (Nat.two_pow_pos w) h, Nat.div_eq_of_lt]
-      · simp
+      · decide
       · omega
 
 @[bv_toNat] theorem getLsbD_succ_last (x : BitVec (w + 1)) :
@@ -512,31 +506,6 @@ theorem eq_zero_or_eq_one (a : BitVec 1) : a = 0#1 ∨ a = 1#1 := by
     subst h
     simp
 
-@[simp]
-theorem toInt_zero {w : Nat} : (0#w).toInt = 0 := by
-  simp [BitVec.toInt, show 0 < 2^w by exact Nat.two_pow_pos w]
-
-/-! ### slt -/
-
-/--
-A bitvector, when interpreted as an integer, is less than zero iff
-its most significant bit is true.
--/
-theorem slt_zero_iff_msb_cond (x : BitVec w) : x.slt 0#w ↔ x.msb = true := by
-  have := toInt_eq_msb_cond x
-  constructor
-  · intros h
-    apply Classical.byContradiction
-    intros hmsb
-    simp only [Bool.not_eq_true] at hmsb
-    simp only [hmsb, Bool.false_eq_true, ↓reduceIte] at this
-    simp only [BitVec.slt, toInt_zero, decide_eq_true_eq] at h
-    omega /- Can't have `x.toInt` which is equal to `x.toNat` be strictly less than zero -/
-  · intros h
-    simp only [h, ↓reduceIte] at this
-    simp [BitVec.slt, this]
-    omega
-
 /-! ### setWidth, zeroExtend and truncate -/
 
 @[simp]
@@ -658,7 +627,7 @@ theorem getElem?_setWidth (m : Nat) (x : BitVec n) (i : Nat) :
 @[simp] theorem setWidth_setWidth_of_le (x : BitVec w) (h : k ≤ l) :
     (x.setWidth l).setWidth k = x.setWidth k := by
   ext i
-  simp only [getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [getLsbD_setWidth, Fin.is_lt, decide_True, Bool.true_and]
   have p := lt_of_getLsbD (x := x) (i := i)
   revert p
   cases getLsbD x i <;> simp; omega
@@ -688,7 +657,7 @@ theorem setWidth_one_eq_ofBool_getLsb_zero (x : BitVec w) :
 theorem setWidth_ofNat_one_eq_ofNat_one_of_lt {v w : Nat} (hv : 0 < v) :
     (BitVec.ofNat v 1).setWidth w = BitVec.ofNat w 1 := by
   ext ⟨i, hilt⟩
-  simp only [getLsbD_setWidth, hilt, decide_true, getLsbD_ofNat, Bool.true_and,
+  simp only [getLsbD_setWidth, hilt, decide_True, getLsbD_ofNat, Bool.true_and,
     Bool.and_iff_right_iff_imp, decide_eq_true_eq]
   intros hi₁
   have hv := Nat.testBit_one_eq_true_iff_self_eq_zero.mp hi₁
@@ -760,9 +729,9 @@ theorem extractLsb'_eq_extractLsb {w : Nat} (x : BitVec w) (start len : Nat) (h
 
 @[simp] theorem ofFin_add_rev (x : Fin (2^n)) : ofFin (x + x.rev) = allOnes n := by
   ext
-  simp only [Fin.rev, getLsbD_ofFin, getLsbD_allOnes, Fin.is_lt, decide_true]
+  simp only [Fin.rev, getLsbD_ofFin, getLsbD_allOnes, Fin.is_lt, decide_True]
   rw [Fin.add_def]
-  simp only [Nat.testBit_mod_two_pow, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [Nat.testBit_mod_two_pow, Fin.is_lt, decide_True, Bool.true_and]
   have h : (x : Nat) + (2 ^ n - (x + 1)) = 2 ^ n - 1 := by omega
   rw [h, Nat.testBit_two_pow_sub_one]
   simp
@@ -1087,7 +1056,7 @@ theorem not_eq_comm {x y : BitVec w} : ~~~ x = y ↔ x = ~~~ y := by
     BitVec.toFin (x <<< n) = Fin.ofNat' (2^w) (x.toNat <<< n) := rfl
 
 @[simp]
-theorem shiftLeft_zero (x : BitVec w) : x <<< 0 = x := by
+theorem shiftLeft_zero_eq (x : BitVec w) : x <<< 0 = x := by
   apply eq_of_toNat_eq
   simp
 
@@ -1114,21 +1083,21 @@ theorem zero_shiftLeft (n : Nat) : 0#w <<< n = 0#w := by
 theorem shiftLeft_xor_distrib (x y : BitVec w) (n : Nat) :
     (x ^^^ y) <<< n = (x <<< n) ^^^ (y <<< n) := by
   ext i
-  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_true, Bool.true_and, getLsbD_xor]
+  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_True, Bool.true_and, getLsbD_xor]
   by_cases h : i < n
     <;> simp [h]
 
 theorem shiftLeft_and_distrib (x y : BitVec w) (n : Nat) :
     (x &&& y) <<< n = (x <<< n) &&& (y <<< n) := by
   ext i
-  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_true, Bool.true_and, getLsbD_and]
+  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_True, Bool.true_and, getLsbD_and]
   by_cases h : i < n
     <;> simp [h]
 
 theorem shiftLeft_or_distrib (x y : BitVec w) (n : Nat) :
     (x ||| y) <<< n = (x <<< n) ||| (y <<< n) := by
   ext i
-  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_true, Bool.true_and, getLsbD_or]
+  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_True, Bool.true_and, getLsbD_or]
   by_cases h : i < n
     <;> simp [h]
 
@@ -1139,9 +1108,9 @@ theorem shiftLeft_or_distrib (x y : BitVec w) (n : Nat) :
   · subst h; simp
   have t : w - 1 - k < w := by omega
   simp only [t]
-  simp only [decide_true, Nat.sub_sub, Bool.true_and, Nat.add_assoc]
+  simp only [decide_True, Nat.sub_sub, Bool.true_and, Nat.add_assoc]
   by_cases h₁ : k < w <;> by_cases h₂ : w - (1 + k) < i <;> by_cases h₃ : k + i < w
-    <;> simp only [h₁, h₂, h₃, decide_false, h₂, decide_true, Bool.not_true, Bool.false_and, Bool.and_self,
+    <;> simp only [h₁, h₂, h₃, decide_False, h₂, decide_True, Bool.not_true, Bool.false_and, Bool.and_self,
       Bool.true_and, Bool.false_eq, Bool.false_and, Bool.not_false]
     <;> (first | apply getLsbD_ge | apply Eq.symm; apply getLsbD_ge)
     <;> omega
@@ -1185,7 +1154,7 @@ theorem shiftLeftZeroExtend_eq {x : BitVec w} :
 theorem shiftLeft_add {w : Nat} (x : BitVec w) (n m : Nat) :
     x <<< (n + m) = (x <<< n) <<< m := by
   ext i
-  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [getLsbD_shiftLeft, Fin.is_lt, decide_True, Bool.true_and]
   rw [show i - (n + m) = (i - m - n) by omega]
   cases h₂ : decide (i < m) <;>
   cases h₃ : decide (i - m < w) <;>
@@ -1257,11 +1226,7 @@ theorem ushiftRight_or_distrib (x y : BitVec w)  (n : Nat) :
   simp
 
 @[simp]
-theorem ushiftRight_zero (x : BitVec w) : x >>> 0 = x := by
-  simp [bv_toNat]
-
-@[simp]
-theorem zero_ushiftRight {n : Nat} : 0#w >>> n = 0#w := by
+theorem ushiftRight_zero_eq (x : BitVec w) : x >>> 0 = x := by
   simp [bv_toNat]
 
 /--
@@ -1283,8 +1248,7 @@ theorem getMsbD_ushiftRight {x : BitVec w} {i n : Nat} :
   · simp [getLsbD_ge, show w ≤ (n + (w - 1 - i)) by omega]
     omega
   · by_cases h₁ : i < w
-    · simp only [h, decide_false, Bool.not_false, show i - n < w by omega, decide_true,
-        Bool.true_and]
+    · simp only [h, ushiftRight_eq, getLsbD_ushiftRight, show i - n < w by omega]
       congr
       omega
     · simp [h, h₁]
@@ -1353,17 +1317,17 @@ theorem getLsbD_sshiftRight (x : BitVec w) (s i : Nat) :
   rcases hmsb : x.msb with rfl | rfl
   · simp only [sshiftRight_eq_of_msb_false hmsb, getLsbD_ushiftRight, Bool.if_false_right]
     by_cases hi : i ≥ w
-    · simp only [hi, decide_true, Bool.not_true, Bool.false_and]
+    · simp only [hi, decide_True, Bool.not_true, Bool.false_and]
       apply getLsbD_ge
       omega
-    · simp only [hi, decide_false, Bool.not_false, Bool.true_and, Bool.iff_and_self,
+    · simp only [hi, decide_False, Bool.not_false, Bool.true_and, Bool.iff_and_self,
         decide_eq_true_eq]
       intros hlsb
       apply BitVec.lt_of_getLsbD hlsb
   · by_cases hi : i ≥ w
     · simp [hi]
     · simp only [sshiftRight_eq_of_msb_true hmsb, getLsbD_not, getLsbD_ushiftRight, Bool.not_and,
-        Bool.not_not, hi, decide_false, Bool.not_false, Bool.if_true_right, Bool.true_and,
+        Bool.not_not, hi, decide_False, Bool.not_false, Bool.if_true_right, Bool.true_and,
         Bool.and_iff_right_iff_imp, Bool.or_eq_true, Bool.not_eq_true', decide_eq_false_iff_not,
         Nat.not_lt, decide_eq_true_eq]
       omega
@@ -1408,7 +1372,7 @@ theorem msb_sshiftRight {n : Nat} {x : BitVec w} :
   rw [msb_eq_getLsbD_last, getLsbD_sshiftRight, msb_eq_getLsbD_last]
   by_cases hw₀ : w = 0
   · simp [hw₀]
-  · simp only [show ¬(w ≤ w - 1) by omega, decide_false, Bool.not_false, Bool.true_and,
+  · simp only [show ¬(w ≤ w - 1) by omega, decide_False, Bool.not_false, Bool.true_and,
       ite_eq_right_iff]
     intros h
     simp [show n = 0 by omega]
@@ -1417,17 +1381,13 @@ theorem msb_sshiftRight {n : Nat} {x : BitVec w} :
   ext i
   simp [getLsbD_sshiftRight]
 
-@[simp] theorem zero_sshiftRight {n : Nat} : (0#w).sshiftRight n = 0#w := by
-  ext i
-  simp [getLsbD_sshiftRight]
-
 theorem sshiftRight_add {x : BitVec w} {m n : Nat} :
     x.sshiftRight (m + n) = (x.sshiftRight m).sshiftRight n := by
   ext i
   simp only [getLsbD_sshiftRight, Nat.add_assoc]
   by_cases h₁ : w ≤ (i : Nat)
   · simp [h₁]
-  · simp only [h₁, decide_false, Bool.not_false, Bool.true_and]
+  · simp only [h₁, decide_False, Bool.not_false, Bool.true_and]
     by_cases h₂ : n + ↑i < w
     · simp [h₂]
     · simp only [h₂, ↓reduceIte]
@@ -1439,7 +1399,7 @@ theorem sshiftRight_add {x : BitVec w} {m n : Nat} :
 theorem not_sshiftRight {b : BitVec w} :
     ~~~b.sshiftRight n = (~~~b).sshiftRight n := by
   ext i
-  simp only [getLsbD_not, Fin.is_lt, decide_true, getLsbD_sshiftRight, Bool.not_and, Bool.not_not,
+  simp only [getLsbD_not, Fin.is_lt, decide_True, getLsbD_sshiftRight, Bool.not_and, Bool.not_not,
     Bool.true_and, msb_not]
   by_cases h : w ≤ i
   <;> by_cases h' : n + i < w
@@ -1457,15 +1417,15 @@ theorem getMsbD_sshiftRight {x : BitVec w} {i n : Nat} :
     getMsbD (x.sshiftRight n) i = (decide (i < w) && if i < n then x.msb else getMsbD x (i - n)) := by
   simp only [getMsbD, BitVec.getLsbD_sshiftRight]
   by_cases h : i < w
-  · simp only [h, decide_true, Bool.true_and]
+  · simp only [h, decide_True, Bool.true_and]
     by_cases h₁ : w ≤ w - 1 - i
     · simp [h₁]
       omega
-    · simp only [h₁, decide_false, Bool.not_false, Bool.true_and]
+    · simp only [h₁, decide_False, Bool.not_false, Bool.true_and]
       by_cases h₂ : i < n
       · simp only [h₂, ↓reduceIte, ite_eq_right_iff]
         omega
-      · simp only [show i - n < w by omega, h₂, ↓reduceIte, decide_true, Bool.true_and]
+      · simp only [show i - n < w by omega, h₂, ↓reduceIte, decide_True, Bool.true_and]
         by_cases h₄ : n + (w - 1 - i) < w <;> (simp only [h₄, ↓reduceIte]; congr; omega)
   · simp [h]
 
@@ -1485,15 +1445,15 @@ theorem getMsbD_sshiftRight' {x y: BitVec w} {i : Nat} :
     (x.sshiftRight y.toNat).getMsbD i = (decide (i < w) && if i < y.toNat then x.msb else x.getMsbD (i - y.toNat)) := by
   simp only [BitVec.sshiftRight', getMsbD, BitVec.getLsbD_sshiftRight]
   by_cases h : i < w
-  · simp only [h, decide_true, Bool.true_and]
+  · simp only [h, decide_True, Bool.true_and]
     by_cases h₁ : w ≤ w - 1 - i
     · simp [h₁]
       omega
-    · simp only [h₁, decide_false, Bool.not_false, Bool.true_and]
+    · simp only [h₁, decide_False, Bool.not_false, Bool.true_and]
       by_cases h₂ : i < y.toNat
       · simp only [h₂, ↓reduceIte, ite_eq_right_iff]
         omega
-      · simp only [show i - y.toNat < w by omega, h₂, ↓reduceIte, decide_true, Bool.true_and]
+      · simp only [show i - y.toNat < w by omega, h₂, ↓reduceIte, decide_True, Bool.true_and]
         by_cases h₄ : y.toNat + (w - 1 - i) < w <;> (simp only [h₄, ↓reduceIte]; congr; omega)
   · simp [h]
 
@@ -1518,11 +1478,11 @@ theorem signExtend_eq_not_setWidth_not_of_msb_false {x : BitVec w} {v : Nat} (hm
     x.signExtend v = x.setWidth v := by
   ext i
   by_cases hv : i < v
-  · simp only [signExtend, getLsbD, getLsbD_setWidth, hv, decide_true, Bool.true_and, toNat_ofInt,
+  · simp only [signExtend, getLsbD, getLsbD_setWidth, hv, decide_True, Bool.true_and, toNat_ofInt,
       BitVec.toInt_eq_msb_cond, hmsb, ↓reduceIte, reduceCtorEq]
     rw [Int.ofNat_mod_ofNat, Int.toNat_ofNat, Nat.testBit_mod_two_pow]
     simp [BitVec.testBit_toNat]
-  · simp only [getLsbD_setWidth, hv, decide_false, Bool.false_and]
+  · simp only [getLsbD_setWidth, hv, decide_False, Bool.false_and]
     apply getLsbD_ge
     omega
 
@@ -1564,7 +1524,7 @@ theorem getElem_signExtend {x  : BitVec w} {v i : Nat} (h : i < v) :
 theorem signExtend_eq_setWidth_of_lt (x : BitVec w) {v : Nat} (hv : v ≤ w):
   x.signExtend v = x.setWidth v := by
   ext i
-  simp only [getLsbD_signExtend, Fin.is_lt, decide_true, Bool.true_and, getLsbD_setWidth,
+  simp only [getLsbD_signExtend, Fin.is_lt, decide_True, Bool.true_and, getLsbD_setWidth,
     ite_eq_left_iff, Nat.not_lt]
   omega
 
@@ -1648,7 +1608,7 @@ theorem setWidth_append {x : BitVec w} {y : BitVec v} :
     (x ++ y).setWidth k = if h : k ≤ v then y.setWidth k else (x.setWidth (k - v) ++ y).cast (by omega) := by
   apply eq_of_getLsbD_eq
   intro i
-  simp only [getLsbD_setWidth, Fin.is_lt, decide_true, getLsbD_append, Bool.true_and]
+  simp only [getLsbD_setWidth, Fin.is_lt, decide_True, getLsbD_append, Bool.true_and]
   split
   · have t : i < v := by omega
     simp [t]
@@ -1660,7 +1620,7 @@ theorem setWidth_append {x : BitVec w} {y : BitVec v} :
 @[simp] theorem setWidth_append_of_eq {x : BitVec v} {y : BitVec w} (h : w' = w) : setWidth (v' + w') (x ++ y) = setWidth v' x ++ setWidth w' y := by
   subst h
   ext i
-  simp only [getLsbD_setWidth, Fin.is_lt, decide_true, getLsbD_append, cond_eq_if,
+  simp only [getLsbD_setWidth, Fin.is_lt, decide_True, getLsbD_append, cond_eq_if,
     decide_eq_true_eq, Bool.true_and, setWidth_eq]
   split
   · simp_all
@@ -1731,13 +1691,13 @@ theorem shiftRight_shiftRight {w : Nat} (x : BitVec w) (n m : Nat) :
 
 theorem getLsbD_rev (x : BitVec w) (i : Fin w) :
     x.getLsbD i.rev = x.getMsbD i := by
-  simp only [getLsbD, Fin.val_rev, getMsbD, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [getLsbD, Fin.val_rev, getMsbD, Fin.is_lt, decide_True, Bool.true_and]
   congr 1
   omega
 
 theorem getElem_rev {x : BitVec w} {i : Fin w}:
     x[i.rev] = x.getMsbD i := by
-  simp only [Fin.getElem_fin, Fin.val_rev, getMsbD, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [Fin.getElem_fin, Fin.val_rev, getMsbD, Fin.is_lt, decide_True, Bool.true_and]
   congr 1
   omega
 
@@ -1767,7 +1727,7 @@ theorem getLsbD_cons (b : Bool) {n} (x : BitVec n) (i : Nat) :
   · 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,
+  · 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_ge, Bool.or_false, ↓reduceIte]
     cases b <;> trivial
   · have p1 : i ≠ n := by omega
@@ -1782,7 +1742,7 @@ theorem getElem_cons {b : Bool} {n} {x : BitVec n} {i : Nat} (h : i < n + 1) :
   · 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,
+  · 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_ge, Bool.or_false, ↓reduceIte]
     cases b <;> trivial
   · have p1 : i ≠ n := by omega
@@ -1802,7 +1762,7 @@ theorem setWidth_succ (x : BitVec w) :
     setWidth (i+1) x = cons (getLsbD x i) (setWidth i x) := by
   apply eq_of_getLsbD_eq
   intro j
-  simp only [getLsbD_setWidth, getLsbD_cons, j.isLt, decide_true, Bool.true_and]
+  simp only [getLsbD_setWidth, getLsbD_cons, j.isLt, decide_True, Bool.true_and]
   if j_eq : j.val = i then
     simp [j_eq]
   else
@@ -1818,7 +1778,7 @@ theorem setWidth_succ (x : BitVec w) :
     · simp_all
     · omega
 
-@[deprecated "Use the reverse direction of `cons_msb_setWidth`" (since := "2024-09-23")]
+@[deprecated "Use the reverse direction of `cons_msb_setWidth`"]
 theorem eq_msb_cons_setWidth (x : BitVec (w+1)) : x = (cons x.msb (x.setWidth w)) := by
   simp
 
@@ -1910,7 +1870,7 @@ theorem getLsbD_shiftConcat_eq_decide (x : BitVec w) (b : Bool) (i : Nat) :
 theorem shiftRight_sub_one_eq_shiftConcat (n : BitVec w) (hwn : 0 < wn) :
     n >>> (wn - 1) = (n >>> wn).shiftConcat (n.getLsbD (wn - 1)) := by
   ext i
-  simp only [getLsbD_ushiftRight, getLsbD_shiftConcat, Fin.is_lt, decide_true, Bool.true_and]
+  simp only [getLsbD_ushiftRight, getLsbD_shiftConcat, Fin.is_lt, decide_True, Bool.true_and]
   split
   · simp [*]
   · congr 1; omega
@@ -1943,31 +1903,6 @@ theorem toNat_shiftConcat_lt_of_lt {x : BitVec w} {b : Bool} {k : Nat}
   ext
   simp [getLsbD_concat]
 
-@[simp]
-theorem getMsbD_concat {i w : Nat} {b : Bool} {x : BitVec w} :
-    (x.concat b).getMsbD i = if i < w then x.getMsbD i else decide (i = w) && b := by
-  simp only [getMsbD_eq_getLsbD, Nat.add_sub_cancel, getLsbD_concat]
-  by_cases h₀ : i = w
-  · simp [h₀]
-  · by_cases h₁ : i < w
-    · simp [h₀, h₁, show ¬ w - i = 0 by omega, show i < w + 1 by omega, Nat.sub_sub, Nat.add_comm]
-    · simp only [show w - i = 0 by omega, ↓reduceIte, h₁, h₀, decide_false, Bool.false_and,
-        Bool.and_eq_false_imp, decide_eq_true_eq]
-      intro
-      omega
-
-@[simp]
-theorem msb_concat {w : Nat} {b : Bool} {x : BitVec w} :
-    (x.concat b).msb = if 0 < w then x.msb else b := by
-  simp only [BitVec.msb, getMsbD_eq_getLsbD, Nat.zero_lt_succ, decide_true, Nat.add_one_sub_one,
-    Nat.sub_zero, Bool.true_and]
-  by_cases h₀ : 0 < w
-  · simp only [Nat.lt_add_one, getLsbD_eq_getElem, getElem_concat, h₀, ↓reduceIte, decide_true,
-      Bool.true_and, ite_eq_right_iff]
-    intro
-    omega
-  · simp [h₀, show w = 0 by omega]
-
 /-! ### add -/
 
 theorem add_def {n} (x y : BitVec n) : x + y = .ofNat n (x.toNat + y.toNat) := rfl
@@ -2039,10 +1974,6 @@ theorem sub_def {n} (x y : BitVec n) : x - y = .ofNat n ((2^n - y.toNat) + x.toN
 @[simp] theorem toNat_sub {n} (x y : BitVec n) :
     (x - y).toNat = (((2^n - y.toNat) + x.toNat) % 2^n) := rfl
 
-@[simp, bv_toNat] theorem toInt_sub {x y : BitVec w} :
-    (x - y).toInt = (x.toInt - y.toInt).bmod (2 ^ w) := by
-  simp [toInt_eq_toNat_bmod, @Int.ofNat_sub y.toNat (2 ^ w) (by omega)]
-
 -- We prefer this lemma to `toNat_sub` for the `bv_toNat` simp set.
 -- For reasons we don't yet understand, unfolding via `toNat_sub` sometimes
 -- results in `omega` generating proof terms that are very slow in the kernel.
@@ -2052,9 +1983,9 @@ theorem sub_def {n} (x y : BitVec n) : x - y = .ofNat n ((2^n - y.toNat) + x.toN
 
 @[simp] theorem toFin_sub (x y : BitVec n) : (x - y).toFin = toFin x - toFin y := rfl
 
-theorem ofFin_sub (x : Fin (2^n)) (y : BitVec n) : .ofFin x - y = .ofFin (x - y.toFin) :=
+@[simp] theorem ofFin_sub (x : Fin (2^n)) (y : BitVec n) : .ofFin x - y = .ofFin (x - y.toFin) :=
   rfl
-theorem sub_ofFin (x : BitVec n) (y : Fin (2^n)) : x - .ofFin y = .ofFin (x.toFin - y) :=
+@[simp] theorem sub_ofFin (x : BitVec n) (y : Fin (2^n)) : x - .ofFin y = .ofFin (x.toFin - y) :=
   rfl
 
 -- Remark: we don't use `[simp]` here because simproc` subsumes it for literals.
@@ -2065,8 +1996,6 @@ theorem ofNat_sub_ofNat {n} (x y : Nat) : BitVec.ofNat n x - BitVec.ofNat n y =
 
 @[simp] protected theorem sub_zero (x : BitVec n) : x - 0#n = x := by apply eq_of_toNat_eq ; simp
 
-@[simp] protected theorem zero_sub (x : BitVec n) : 0#n - x = -x := rfl
-
 @[simp] protected theorem sub_self (x : BitVec n) : x - x = 0#n := by
   apply eq_of_toNat_eq
   simp only [toNat_sub]
@@ -2079,8 +2008,18 @@ theorem ofNat_sub_ofNat {n} (x y : Nat) : BitVec.ofNat n x - BitVec.ofNat n y =
 
 theorem toInt_neg {x : BitVec w} :
     (-x).toInt = (-x.toInt).bmod (2 ^ w) := by
-  rw [← BitVec.zero_sub, toInt_sub]
-  simp [BitVec.toInt_ofNat]
+  simp only [toInt_eq_toNat_bmod, toNat_neg, Int.ofNat_emod, Int.emod_bmod_congr]
+  rw [← Int.subNatNat_of_le (by omega), Int.subNatNat_eq_coe, Int.sub_eq_add_neg, Int.add_comm,
+    Int.bmod_add_cancel]
+  by_cases h : x.toNat < ((2 ^ w) + 1) / 2
+  · rw [Int.bmod_pos (x := x.toNat)]
+    all_goals simp only [toNat_mod_cancel']
+    norm_cast
+  · rw [Int.bmod_neg (x := x.toNat)]
+    · simp only [toNat_mod_cancel']
+      rw_mod_cast [Int.neg_sub, Int.sub_eq_add_neg, Int.add_comm, Int.bmod_add_cancel]
+    · norm_cast
+      simp_all
 
 @[simp] theorem toFin_neg (x : BitVec n) :
     (-x).toFin = Fin.ofNat' (2^n) (2^n - x.toNat) :=
@@ -2172,6 +2111,17 @@ theorem not_neg (x : BitVec w) : ~~~(-x) = x + -1#w := by
         show (_ - x.toNat) % _ = _ by rw [Nat.mod_eq_of_lt (by omega)]]
       omega
 
+/-! ### abs -/
+
+@[simp, bv_toNat]
+theorem toNat_abs {x : BitVec w} : x.abs.toNat = if x.msb then 2^w - x.toNat else x.toNat := by
+  simp only [BitVec.abs, neg_eq]
+  by_cases h : x.msb = true
+  · simp only [h, ↓reduceIte, toNat_neg]
+    have : 2 * x.toNat ≥ 2 ^ w := BitVec.msb_eq_true_iff_two_mul_ge.mp h
+    rw [Nat.mod_eq_of_lt (by omega)]
+  · simp [h]
+
 /-! ### mul -/
 
 theorem mul_def {n} {x y : BitVec n} : x * y = (ofFin <| x.toFin * y.toFin) := by rfl
@@ -2199,23 +2149,18 @@ instance : Std.LawfulCommIdentity (fun (x y : BitVec w) => x * y) (1#w) where
   right_id := BitVec.mul_one
 
 @[simp]
-theorem mul_zero {x : BitVec w} : x * 0#w = 0#w := by
+theorem BitVec.mul_zero {x : BitVec w} : x * 0#w = 0#w := by
   apply eq_of_toNat_eq
   simp [toNat_mul]
 
-@[simp]
-theorem zero_mul {x : BitVec w} : 0#w * x = 0#w := by
-  apply eq_of_toNat_eq
-  simp [toNat_mul]
-
-theorem mul_add {x y z : BitVec w} :
+theorem BitVec.mul_add {x y z : BitVec w} :
     x * (y + z) = x * y + x * z := by
   apply eq_of_toNat_eq
   simp only [toNat_mul, toNat_add, Nat.add_mod_mod, Nat.mod_add_mod]
   rw [Nat.mul_mod, Nat.mod_mod (y.toNat + z.toNat),
     ← Nat.mul_mod, Nat.mul_add]
 
-theorem mul_succ {x y : BitVec w} : x * (y + 1#w) = x * y + x := by simp [mul_add]
+theorem mul_succ {x y : BitVec w} : x * (y + 1#w) = x * y + x := by simp [BitVec.mul_add]
 theorem succ_mul {x y : BitVec w} : (x + 1#w) * y = x * y + y := by simp [BitVec.mul_comm, BitVec.mul_add]
 
 theorem mul_two {x : BitVec w} : x * 2#w = x + x := by
@@ -2396,14 +2341,6 @@ theorem umod_eq_and {x y : BitVec 1} : x % y = x &&& (~~~y) := by
     rcases hy with rfl | rfl <;>
       rfl
 
-/-! ### smtUDiv -/
-
-theorem smtUDiv_eq (x y : BitVec w) : smtUDiv x y = if y = 0#w then allOnes w else x / y := by
-  simp [smtUDiv]
-
-@[simp]
-theorem smtUDiv_zero {x : BitVec n} : x.smtUDiv 0#n = allOnes n := rfl
-
 /-! ### sdiv -/
 
 /-- Equation theorem for `sdiv` in terms of `udiv`. -/
@@ -2460,32 +2397,6 @@ theorem sdiv_self {x : BitVec w} :
       rcases x.msb with msb | msb <;> simp
     · rcases x.msb with msb | msb <;> simp [h]
 
-/-! ### smtSDiv -/
-
-theorem smtSDiv_eq (x y : BitVec w) : smtSDiv x y =
-  match x.msb, y.msb with
-  | false, false => smtUDiv x y
-  | false, true  => -(smtUDiv x (-y))
-  | true,  false => -(smtUDiv (-x) y)
-  | true,  true  => smtUDiv (-x) (-y) := by
-  rw [BitVec.smtSDiv]
-  rcases x.msb <;> rcases y.msb <;> simp
-
-@[simp]
-theorem smtSDiv_zero {x : BitVec n} : x.smtSDiv 0#n = if x.slt 0#n then 1#n else (allOnes n) := by
-  rcases hx : x.msb <;> simp [smtSDiv, slt_zero_iff_msb_cond x, hx, ← negOne_eq_allOnes]
-
-/-! ### srem -/
-
-theorem srem_eq (x y : BitVec w) : srem x y =
-  match x.msb, y.msb with
-  | false, false => x % y
-  | false, true  => x % (-y)
-  | true,  false => - ((-x) % y)
-  | true,  true  => -((-x) % (-y)) := by
-  rw [BitVec.srem]
-  rcases x.msb <;> rcases y.msb <;> simp
-
 /-! ### smod -/
 
 /-- Equation theorem for `smod` in terms of `umod`. -/
@@ -2539,7 +2450,7 @@ theorem smod_zero {x : BitVec n} : x.smod 0#n = x := by
 @[simp] theorem getElem_ofBoolListBE (h : i < bs.length) :
     (ofBoolListBE bs)[i] = bs[bs.length - 1 - i] := by
   rw [← getLsbD_eq_getElem, getLsbD_ofBoolListBE]
-  simp only [h, decide_true, List.getD_eq_getElem?_getD, Bool.true_and]
+  simp only [h, decide_True, List.getD_eq_getElem?_getD, Bool.true_and]
   rw [List.getElem?_eq_getElem (by omega)]
   simp
 
@@ -2727,9 +2638,6 @@ theorem getElem_rotateRight {x : BitVec w} {r i : Nat} (h : i < w) :
 
 /- ## twoPow -/
 
-theorem twoPow_eq (w : Nat) (i : Nat) : twoPow w i = 1#w <<< i := by
-  dsimp [twoPow]
-
 @[simp, bv_toNat]
 theorem toNat_twoPow (w : Nat) (i : Nat) : (twoPow w i).toNat = 2^i % 2^w := by
   rcases w with rfl | w
@@ -2744,7 +2652,7 @@ theorem getLsbD_twoPow (i j : Nat) : (twoPow w i).getLsbD j = ((i < w) && (i = j
   · simp
   · simp only [twoPow, getLsbD_shiftLeft, getLsbD_ofNat]
     by_cases hj : j < i
-    · simp only [hj, decide_true, Bool.not_true, Bool.and_false, Bool.false_and, Bool.false_eq,
+    · simp only [hj, decide_True, Bool.not_true, Bool.and_false, Bool.false_and, Bool.false_eq,
       Bool.and_eq_false_imp, decide_eq_true_eq, decide_eq_false_iff_not]
       omega
     · by_cases hi : Nat.testBit 1 (j - i)
@@ -2762,21 +2670,6 @@ theorem getElem_twoPow {i j : Nat} (h : j < w) : (twoPow w i)[j] = decide (j = i
   simp [eq_comm]
   omega
 
-@[simp]
-theorem getMsbD_twoPow {i j w: Nat} :
-    (twoPow w i).getMsbD j = (decide (i < w) && decide (j = w - i - 1)) := by
-  simp only [getMsbD_eq_getLsbD, getLsbD_twoPow]
-  by_cases h₀ : i < w <;> by_cases h₁ : j < w <;>
-  simp [h₀, h₁] <;> omega
-
-@[simp]
-theorem msb_twoPow {i w: Nat} :
-    (twoPow w i).msb = (decide (i < w) && decide (i = w - 1)) := by
-  simp only [BitVec.msb, getMsbD_eq_getLsbD, Nat.sub_zero, getLsbD_twoPow,
-    Bool.and_iff_right_iff_imp, Bool.and_eq_true, decide_eq_true_eq, and_imp]
-  intros
-  omega
-
 theorem and_twoPow (x : BitVec w) (i : Nat) :
     x &&& (twoPow w i) = if x.getLsbD i then twoPow w i else 0#w := by
   ext j
@@ -2807,15 +2700,7 @@ theorem twoPow_zero {w : Nat} : twoPow w 0 = 1#w := by
 theorem shiftLeft_eq_mul_twoPow (x : BitVec w) (n : Nat) :
     x <<< n = x * (BitVec.twoPow w n) := by
   ext i
-  simp [getLsbD_shiftLeft, Fin.is_lt, decide_true, Bool.true_and, mul_twoPow_eq_shiftLeft]
-
-/--
-The unsigned division of `x` by `2^k` equals shifting `x` right by `k`,
-when `k` is less than the bitwidth `w`.
--/
-theorem udiv_twoPow_eq_of_lt {w : Nat} {x : BitVec w} {k : Nat} (hk : k < w) : x / (twoPow w k) = x >>> k := by
-  have : 2^k < 2^w := Nat.pow_lt_pow_of_lt (by decide) hk
-  simp [bv_toNat, Nat.shiftRight_eq_div_pow, Nat.mod_eq_of_lt this]
+  simp [getLsbD_shiftLeft, Fin.is_lt, decide_True, Bool.true_and, mul_twoPow_eq_shiftLeft]
 
 /- ### cons -/
 
@@ -2843,7 +2728,7 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_of_getLsbD_false
     setWidth w (x.setWidth (i + 1)) =
       setWidth w (x.setWidth i) := by
   ext k
-  simp only [getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and, getLsbD_or, getLsbD_and]
+  simp only [getLsbD_setWidth, Fin.is_lt, decide_True, Bool.true_and, getLsbD_or, getLsbD_and]
   by_cases hik : i = k
   · subst hik
     simp [hx]
@@ -2859,7 +2744,7 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_or_twoPow_of_getLsbD_true
     setWidth w (x.setWidth (i + 1)) =
       setWidth w (x.setWidth i) ||| (twoPow w i) := by
   ext k
-  simp only [getLsbD_setWidth, Fin.is_lt, decide_true, Bool.true_and, getLsbD_or, getLsbD_and]
+  simp only [getLsbD_setWidth, Fin.is_lt, decide_True, Bool.true_and, getLsbD_or, getLsbD_and]
   by_cases hik : i = k
   · subst hik
     simp [hx]
@@ -2869,7 +2754,7 @@ theorem setWidth_setWidth_succ_eq_setWidth_setWidth_or_twoPow_of_getLsbD_true
 theorem and_one_eq_setWidth_ofBool_getLsbD {x : BitVec w} :
     (x &&& 1#w) = setWidth w (ofBool (x.getLsbD 0)) := by
   ext i
-  simp only [getLsbD_and, getLsbD_one, getLsbD_setWidth, Fin.is_lt, decide_true, getLsbD_ofBool,
+  simp only [getLsbD_and, getLsbD_one, getLsbD_setWidth, Fin.is_lt, decide_True, getLsbD_ofBool,
     Bool.true_and]
   by_cases h : ((i : Nat) = 0) <;> simp [h] <;> omega
 
@@ -2906,13 +2791,13 @@ theorem getLsbD_replicate {n w : Nat} (x : BitVec w) :
   case succ n ih =>
     simp only [replicate_succ_eq, getLsbD_cast, getLsbD_append]
     by_cases hi : i < w * (n + 1)
-    · simp only [hi, decide_true, Bool.true_and]
+    · simp only [hi, decide_True, Bool.true_and]
       by_cases hi' : i < w * n
       · simp [hi', ih]
-      · simp only [hi', decide_false, cond_false]
+      · simp only [hi', decide_False, cond_false]
         rw [Nat.sub_mul_eq_mod_of_lt_of_le] <;> omega
     · rw [Nat.mul_succ] at hi ⊢
-      simp only [show ¬i < w * n by omega, decide_false, cond_false, hi, Bool.false_and]
+      simp only [show ¬i < w * n by omega, decide_False, cond_false, hi, Bool.false_and]
       apply BitVec.getLsbD_ge (x := x) (i := i - w * n) (ge := by omega)
 
 @[simp]
@@ -2930,14 +2815,6 @@ theorem getLsbD_intMin (w : Nat) : (intMin w).getLsbD i = decide (i + 1 = w) :=
   simp only [intMin, getLsbD_twoPow, boolToPropSimps]
   omega
 
-theorem getMsbD_intMin {w i : Nat} :
-    (intMin w).getMsbD i = (decide (0 < w) && decide (i = 0)) := by
-  simp only [getMsbD, getLsbD_intMin]
-  match w, i with
-  | 0,   _    => simp
-  | w+1, 0    => simp
-  | w+1, i+1  => simp; omega
-
 /--
 The RHS is zero in case `w = 0` which is modeled by wrapping the expression in `... % 2 ^ w`.
 -/
@@ -2960,21 +2837,6 @@ theorem toInt_intMin {w : Nat} :
     rw [Nat.mul_comm]
     simp [w_pos]
 
-theorem toInt_intMin_le (x : BitVec w) :
-    (intMin w).toInt ≤ x.toInt := by
-  cases w
-  case zero => simp [@of_length_zero x]
-  case succ w =>
-    simp only [toInt_intMin, Nat.add_one_sub_one, Int.ofNat_emod]
-    have : 0 < 2 ^ w := Nat.two_pow_pos w
-    rw [Int.emod_eq_of_lt (by omega) (by omega)]
-    rw [BitVec.toInt_eq_toNat_bmod]
-    rw [show (2 ^ w : Nat) = ((2 ^ (w + 1) : Nat) : Int) / 2 by omega]
-    apply Int.le_bmod (by omega)
-
-theorem intMin_sle (x : BitVec w) : (intMin w).sle x := by
-  simp only [BitVec.sle, toInt_intMin_le x, decide_true]
-
 @[simp]
 theorem neg_intMin {w : Nat} : -intMin w = intMin w := by
   by_cases h : 0 < w
@@ -2982,10 +2844,6 @@ theorem neg_intMin {w : Nat} : -intMin w = intMin w := by
   · simp only [Nat.not_lt, Nat.le_zero_eq] at h
     simp [bv_toNat, h]
 
-@[simp]
-theorem abs_intMin {w : Nat} : (intMin w).abs = intMin w := by
-  simp [BitVec.abs, bv_toNat]
-
 theorem toInt_neg_of_ne_intMin {x : BitVec w} (rs : x ≠ intMin w) :
     (-x).toInt = -(x.toInt) := by
   simp only [ne_eq, toNat_eq, toNat_intMin] at rs
@@ -3002,10 +2860,6 @@ theorem toInt_neg_of_ne_intMin {x : BitVec w} (rs : x ≠ intMin w) :
   have := @Nat.two_pow_pred_mul_two w (by omega)
   split <;> split <;> omega
 
-theorem msb_intMin {w : Nat} : (intMin w).msb = decide (0 < w) := by
-  simp only [msb_eq_decide, toNat_intMin, decide_eq_decide]
-  by_cases h : 0 < w <;> simp_all
-
 /-! ### intMax -/
 
 /-- The bitvector of width `w` that has the largest value when interpreted as an integer. -/
@@ -3098,38 +2952,6 @@ theorem sub_le_sub_iff_le {x y z : BitVec w} (hxz : z ≤ x) (hyz : z ≤ y) :
     BitVec.toNat_sub_of_le (by rw [BitVec.le_def]; omega)]
   omega
 
-/-! ### neg -/
-
-theorem msb_eq_toInt {x : BitVec w}:
-    x.msb = decide (x.toInt < 0) := by
-  by_cases h : x.msb <;>
-  · simp [h, toInt_eq_msb_cond]
-    omega
-
-theorem msb_eq_toNat {x : BitVec w}:
-    x.msb = decide (x.toNat ≥ 2 ^ (w - 1)) := by
-  simp only [msb_eq_decide, ge_iff_le]
-
-/-! ### abs -/
-
-theorem abs_eq (x : BitVec w) : x.abs = if x.msb then -x else x := by rfl
-
-@[simp, bv_toNat]
-theorem toNat_abs {x : BitVec w} : x.abs.toNat = if x.msb then 2^w - x.toNat else x.toNat := by
-  simp only [BitVec.abs, neg_eq]
-  by_cases h : x.msb = true
-  · simp only [h, ↓reduceIte, toNat_neg]
-    have : 2 * x.toNat ≥ 2 ^ w := BitVec.msb_eq_true_iff_two_mul_ge.mp h
-    rw [Nat.mod_eq_of_lt (by omega)]
-  · simp [h]
-
-theorem getLsbD_abs {i : Nat} {x : BitVec w} :
-   getLsbD x.abs i = if x.msb then getLsbD (-x) i else getLsbD x i := by
-  by_cases h : x.msb <;> simp [BitVec.abs, h]
-
-theorem getMsbD_abs {i : Nat} {x : BitVec w} :
-    getMsbD (x.abs) i = if x.msb then getMsbD (-x) i else getMsbD x i := by
-  by_cases h : x.msb <;> simp [BitVec.abs, h]
 
 /-! ### Decidable quantifiers -/
 
@@ -3338,10 +3160,4 @@ abbrev and_one_eq_zeroExtend_ofBool_getLsbD := @and_one_eq_setWidth_ofBool_getLs
 @[deprecated msb_sshiftRight (since := "2024-10-03")]
 abbrev sshiftRight_msb_eq_msb := @msb_sshiftRight
 
-@[deprecated shiftLeft_zero (since := "2024-10-27")]
-abbrev shiftLeft_zero_eq := @shiftLeft_zero
-
-@[deprecated ushiftRight_zero (since := "2024-10-27")]
-abbrev ushiftRight_zero_eq := @ushiftRight_zero
-
 end BitVec

src/Init/Data/ByteArray/Basic.lean

@@ -42,7 +42,7 @@ def usize (a : @& ByteArray) : USize :=
   a.size.toUSize
 
 @[extern "lean_byte_array_uget"]
-def uget : (a : @& ByteArray) → (i : USize) → (h : i.toNat < a.size := by get_elem_tactic) → UInt8
+def uget : (a : @& ByteArray) → (i : USize) → i.toNat < a.size → UInt8
   | ⟨bs⟩, i, h => bs[i]
 
 @[extern "lean_byte_array_get"]
@@ -50,11 +50,11 @@ def get! : (@& ByteArray) → (@& Nat) → UInt8
   | ⟨bs⟩, i => bs.get! i
 
 @[extern "lean_byte_array_fget"]
-def get : (a : @& ByteArray) → (i : @& Nat) → (h : i < a.size := by get_elem_tactic) → UInt8
-  | ⟨bs⟩, i, _ => bs[i]
+def get : (a : @& ByteArray) → (@& Fin a.size) → UInt8
+  | ⟨bs⟩, i => bs.get i
 
 instance : GetElem ByteArray Nat UInt8 fun xs i => i < xs.size where
-  getElem xs i h := xs.get i
+  getElem xs i h := xs.get ⟨i, h⟩
 
 instance : GetElem ByteArray USize UInt8 fun xs i => i.val < xs.size where
   getElem xs i h := xs.uget i h
@@ -64,11 +64,11 @@ def set! : ByteArray → (@& Nat) → UInt8 → ByteArray
   | ⟨bs⟩, i, b => ⟨bs.set! i b⟩
 
 @[extern "lean_byte_array_fset"]
-def set : (a : ByteArray) → (i : @& Nat) → UInt8 → (h : i < a.size := by get_elem_tactic) → ByteArray
-  | ⟨bs⟩, i, b, h => ⟨bs.set i b h⟩
+def set : (a : ByteArray) → (@& Fin a.size) → UInt8 → ByteArray
+  | ⟨bs⟩, i, b => ⟨bs.set i b⟩
 
 @[extern "lean_byte_array_uset"]
-def uset : (a : ByteArray) → (i : USize) → UInt8 → (h : i.toNat < a.size := by get_elem_tactic) → ByteArray
+def uset : (a : ByteArray) → (i : USize) → UInt8 → i.toNat < a.size → ByteArray
   | ⟨bs⟩, i, v, h => ⟨bs.uset i v h⟩
 
 @[extern "lean_byte_array_hash"]
@@ -144,7 +144,7 @@ protected def forIn {β : Type v} {m : Type v → Type w} [Monad m] (as : ByteAr
       have h' : i < as.size            := Nat.lt_of_lt_of_le (Nat.lt_succ_self i) h
       have : as.size - 1 < as.size     := Nat.sub_lt (Nat.zero_lt_of_lt h') (by decide)
       have : as.size - 1 - i < as.size := Nat.lt_of_le_of_lt (Nat.sub_le (as.size - 1) i) this
-      match (← f as[as.size - 1 - i] b) with
+      match (← f (as.get ⟨as.size - 1 - i, this⟩) b) with
       | ForInStep.done b  => pure b
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
@@ -178,7 +178,7 @@ def foldlM {β : Type v} {m : Type v → Type w} [Monad m] (f : β → UInt8 →
         match i with
         | 0    => pure b
         | i'+1 =>
-          loop i' (j+1) (← f b as[j])
+          loop i' (j+1) (← f b (as.get ⟨j, Nat.lt_of_lt_of_le hlt h⟩))
       else
         pure b
     loop (stop - start) start init

src/Init/Data/Fin/Basic.lean

@@ -165,7 +165,6 @@ theorem modn_lt : ∀ {m : Nat} (i : Fin n), m > 0 → (modn i m).val < m
 theorem val_lt_of_le (i : Fin b) (h : b ≤ n) : i.val < n :=
   Nat.lt_of_lt_of_le i.isLt h
 
-/-- If you actually have an element of `Fin n`, then the `n` is always positive -/
 protected theorem pos (i : Fin n) : 0 < n :=
   Nat.lt_of_le_of_lt (Nat.zero_le _) i.2
 

src/Init/Data/Fin/Fold.lean

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

src/Init/Data/Fin/Lemmas.lean

@@ -13,19 +13,17 @@ import Init.Omega
 
 namespace Fin
 
-@[deprecated Fin.pos (since := "2024-11-11")]
-theorem size_pos (i : Fin n) : 0 < n := i.pos
+/-- If you actually have an element of `Fin n`, then the `n` is always positive -/
+theorem size_pos (i : Fin n) : 0 < n := Nat.lt_of_le_of_lt (Nat.zero_le _) i.2
 
 theorem mod_def (a m : Fin n) : a % m = Fin.mk (a % m) (Nat.lt_of_le_of_lt (Nat.mod_le _ _) a.2) :=
   rfl
 
-theorem mul_def (a b : Fin n) : a * b = Fin.mk ((a * b) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem mul_def (a b : Fin n) : a * b = Fin.mk ((a * b) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
-theorem sub_def (a b : Fin n) : a - b = Fin.mk (((n - b) + a) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem sub_def (a b : Fin n) : a - b = Fin.mk (((n - b) + a) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
-theorem pos' : ∀ [Nonempty (Fin n)], 0 < n | ⟨i⟩ => i.pos
-
-@[deprecated pos' (since := "2024-11-11")] abbrev size_pos' := @pos'
+theorem size_pos' : ∀ [Nonempty (Fin n)], 0 < n | ⟨i⟩ => i.size_pos
 
 @[simp] theorem is_lt (a : Fin n) : (a : Nat) < n := a.2
 
@@ -242,7 +240,7 @@ theorem fin_one_eq_zero (a : Fin 1) : a = 0 := Subsingleton.elim a 0
   rw [eq_comm]
   simp
 
-theorem add_def (a b : Fin n) : a + b = Fin.mk ((a + b) % n) (Nat.mod_lt _ a.pos) := rfl
+theorem add_def (a b : Fin n) : a + b = Fin.mk ((a + b) % n) (Nat.mod_lt _ a.size_pos) := rfl
 
 theorem val_add (a b : Fin n) : (a + b).val = (a.val + b.val) % n := rfl
 

src/Init/Data/FloatArray/Basic.lean

@@ -46,8 +46,8 @@ def uget : (a : @& FloatArray) → (i : USize) → i.toNat < a.size → Float
   | ⟨ds⟩, i, h => ds[i]
 
 @[extern "lean_float_array_fget"]
-def get : (ds : @& FloatArray) → (i : @& Nat) → (h : i < ds.size := by get_elem_tactic) → Float
-  | ⟨ds⟩, i, h => ds.get i h
+def get : (ds : @& FloatArray) → (@& Fin ds.size) → Float
+  | ⟨ds⟩, i => ds.get i
 
 @[extern "lean_float_array_get"]
 def get! : (@& FloatArray) → (@& Nat) → Float
@@ -55,23 +55,23 @@ def get! : (@& FloatArray) → (@& Nat) → Float
 
 def get? (ds : FloatArray) (i : Nat) : Option Float :=
   if h : i < ds.size then
-    some (ds.get i h)
+    ds.get ⟨i, h⟩
   else
     none
 
 instance : GetElem FloatArray Nat Float fun xs i => i < xs.size where
-  getElem xs i h := xs.get i h
+  getElem xs i h := xs.get ⟨i, h⟩
 
 instance : GetElem FloatArray USize Float fun xs i => i.val < xs.size where
   getElem xs i h := xs.uget i h
 
 @[extern "lean_float_array_uset"]
-def uset : (a : FloatArray) → (i : USize) → Float → (h : i.toNat < a.size := by get_elem_tactic) → FloatArray
+def uset : (a : FloatArray) → (i : USize) → Float → i.toNat < a.size → FloatArray
   | ⟨ds⟩, i, v, h => ⟨ds.uset i v h⟩
 
 @[extern "lean_float_array_fset"]
-def set : (ds : FloatArray) → (i : @& Nat) → Float → (h : i < ds.size := by get_elem_tactic) → FloatArray
-  | ⟨ds⟩, i, d, h => ⟨ds.set i d h⟩
+def set : (ds : FloatArray) → (@& Fin ds.size) → Float → FloatArray
+  | ⟨ds⟩, i, d => ⟨ds.set i d⟩
 
 @[extern "lean_float_array_set"]
 def set! : FloatArray → (@& Nat) → Float → FloatArray
@@ -83,7 +83,7 @@ def isEmpty (s : FloatArray) : Bool :=
 partial def toList (ds : FloatArray) : List Float :=
   let rec loop (i r) :=
     if h : i < ds.size then
-      loop (i+1) (ds[i] :: r)
+      loop (i+1) (ds.get ⟨i, h⟩ :: r)
     else
       r.reverse
   loop 0 []
@@ -115,7 +115,7 @@ protected def forIn {β : Type v} {m : Type v → Type w} [Monad m] (as : FloatA
       have h' : i < as.size            := Nat.lt_of_lt_of_le (Nat.lt_succ_self i) h
       have : as.size - 1 < as.size     := Nat.sub_lt (Nat.zero_lt_of_lt h') (by decide)
       have : as.size - 1 - i < as.size := Nat.lt_of_le_of_lt (Nat.sub_le (as.size - 1) i) this
-      match (← f as[as.size - 1 - i] b) with
+      match (← f (as.get ⟨as.size - 1 - i, this⟩) b) with
       | ForInStep.done b  => pure b
       | ForInStep.yield b => loop i (Nat.le_of_lt h') b
   loop as.size (Nat.le_refl _) b
@@ -149,7 +149,7 @@ def foldlM {β : Type v} {m : Type v → Type w} [Monad m] (f : β → Float →
         match i with
         | 0    => pure b
         | i'+1 =>
-          loop i' (j+1) (← f b (as[j]'(Nat.lt_of_lt_of_le hlt h)))
+          loop i' (j+1) (← f b (as.get ⟨j, Nat.lt_of_lt_of_le hlt h⟩))
       else
         pure b
     loop (stop - start) start init

src/Init/Data/Hashable.lean

@@ -48,15 +48,9 @@ instance : Hashable UInt64 where
 instance : Hashable USize where
   hash n := n.toUInt64
 
-instance : Hashable ByteArray where
-  hash as := as.foldl (fun r a => mixHash r (hash a)) 7
-
 instance : Hashable (Fin n) where
   hash v := v.val.toUInt64
 
-instance : Hashable Char where
-  hash c := c.val.toUInt64
-
 instance : Hashable Int where
   hash
     | Int.ofNat n => UInt64.ofNat (2 * n)

src/Init/Data/Int/DivModLemmas.lean

@@ -1125,17 +1125,6 @@ theorem emod_add_bmod_congr (x : Int) (n : Nat) : Int.bmod (x%n + y) n = Int.bmo
   simp [Int.emod_def, Int.sub_eq_add_neg]
   rw [←Int.mul_neg, Int.add_right_comm,  Int.bmod_add_mul_cancel]
 
-@[simp]
-theorem emod_sub_bmod_congr (x : Int) (n : Nat) : Int.bmod (x%n - y) n = Int.bmod (x - y) n := by
-  simp only [emod_def, Int.sub_eq_add_neg]
-  rw [←Int.mul_neg, Int.add_right_comm,  Int.bmod_add_mul_cancel]
-
-@[simp]
-theorem sub_emod_bmod_congr (x : Int) (n : Nat) : Int.bmod (x - y%n) n = Int.bmod (x - y) n := by
-  simp only [emod_def]
-  rw [Int.sub_eq_add_neg, Int.neg_sub, Int.sub_eq_add_neg, ← Int.add_assoc, Int.add_right_comm,
-    Int.bmod_add_mul_cancel, Int.sub_eq_add_neg]
-
 @[simp]
 theorem emod_mul_bmod_congr (x : Int) (n : Nat) : Int.bmod (x%n * y) n = Int.bmod (x * y) n := by
   simp [Int.emod_def, Int.sub_eq_add_neg]
@@ -1151,28 +1140,9 @@ theorem bmod_add_bmod_congr : Int.bmod (Int.bmod x n + y) n = Int.bmod (x + y) n
     rw [Int.sub_eq_add_neg, Int.add_right_comm, ←Int.sub_eq_add_neg]
     simp
 
-@[simp]
-theorem bmod_sub_bmod_congr : Int.bmod (Int.bmod x n - y) n = Int.bmod (x - y) n := by
-  rw [Int.bmod_def x n]
-  split
-  next p =>
-    simp only [emod_sub_bmod_congr]
-  next p =>
-    rw [Int.sub_eq_add_neg, Int.sub_eq_add_neg, Int.add_right_comm, ←Int.sub_eq_add_neg, ← Int.sub_eq_add_neg]
-    simp [emod_sub_bmod_congr]
-
 @[simp] theorem add_bmod_bmod : Int.bmod (x + Int.bmod y n) n = Int.bmod (x + y) n := by
   rw [Int.add_comm x, Int.bmod_add_bmod_congr, Int.add_comm y]
 
-@[simp] theorem sub_bmod_bmod : Int.bmod (x - Int.bmod y n) n = Int.bmod (x - y) n := by
-  rw [Int.bmod_def y n]
-  split
-  next p =>
-    simp [sub_emod_bmod_congr]
-  next p =>
-    rw [Int.sub_eq_add_neg, Int.sub_eq_add_neg, Int.neg_add, Int.neg_neg, ← Int.add_assoc, ← Int.sub_eq_add_neg]
-    simp [sub_emod_bmod_congr]
-
 @[simp]
 theorem bmod_mul_bmod : Int.bmod (Int.bmod x n * y) n = Int.bmod (x * y) n := by
   rw [bmod_def x n]
@@ -1267,7 +1237,7 @@ theorem bmod_le {x : Int} {m : Nat} (h : 0 < m) : bmod x m ≤ (m - 1) / 2 := by
     _ = ((m + 1 - 2) + 2)/2 := by simp
     _ = (m - 1) / 2 + 1     := by
       rw [add_ediv_of_dvd_right]
-      · simp +decide only [Int.ediv_self]
+      · simp (config := {decide := true}) only [Int.ediv_self]
         congr 2
         rw [Int.add_sub_assoc, ← Int.sub_neg]
         congr
@@ -1285,7 +1255,7 @@ theorem bmod_natAbs_plus_one (x : Int) (w : 1 < x.natAbs) : bmod x (x.natAbs + 1
     simp only [bmod, ofNat_eq_coe, natAbs_ofNat, natCast_add, ofNat_one,
       emod_self_add_one (ofNat_nonneg x)]
     match x with
-    | 0 => rw [if_pos] <;> simp +decide
+    | 0 => rw [if_pos] <;> simp (config := {decide := true})
     | (x+1) =>
       rw [if_neg]
       · simp [← Int.sub_sub]

src/Init/Data/Int/Order.lean

@@ -1007,9 +1007,9 @@ theorem sign_eq_neg_one_iff_neg {a : Int} : sign a = -1 ↔ a < 0 :=
   match x with
   | 0 => rfl
   | .ofNat (_ + 1) =>
-    simp +decide only [sign, true_iff]
+    simp (config := { decide := true }) only [sign, true_iff]
     exact Int.le_add_one (ofNat_nonneg _)
-  | .negSucc _ => simp +decide [sign]
+  | .negSucc _ => simp (config := { decide := true }) [sign]
 
 theorem mul_sign : ∀ i : Int, i * sign i = natAbs i
   | succ _ => Int.mul_one _

src/Init/Data/List.lean

@@ -25,4 +25,3 @@ import Init.Data.List.Perm
 import Init.Data.List.Sort
 import Init.Data.List.ToArray
 import Init.Data.List.MapIdx
-import Init.Data.List.OfFn

src/Init/Data/List/Attach.lean

@@ -169,13 +169,6 @@ theorem pmap_ne_nil_iff {P : α → Prop} (f : (a : α) → P a → β) {xs : Li
     (H : ∀ (a : α), a ∈ xs → P a) : xs.pmap f H ≠ [] ↔ xs ≠ [] := by
   simp
 
-theorem pmap_eq_self {l : List α} {p : α → Prop} (hp : ∀ (a : α), a ∈ l → p a)
-    (f : (a : α) → p a → α) : l.pmap f hp = l ↔ ∀ a (h : a ∈ l), f a (hp a h) = a := by
-  rw [pmap_eq_map_attach]
-  conv => lhs; rhs; rw [← attach_map_subtype_val l]
-  rw [map_inj_left]
-  simp
-
 @[simp]
 theorem attach_eq_nil_iff {l : List α} : l.attach = [] ↔ l = [] :=
   pmap_eq_nil_iff

src/Init/Data/List/Basic.lean

@@ -29,7 +29,7 @@ The operations are organized as follow:
 * Lexicographic ordering: `lt`, `le`, and instances.
 * Head and tail operators: `head`, `head?`, `headD?`, `tail`, `tail?`, `tailD`.
 * Basic operations:
-  `map`, `filter`, `filterMap`, `foldr`, `append`, `flatten`, `pure`, `flatMap`, `replicate`, and
+  `map`, `filter`, `filterMap`, `foldr`, `append`, `flatten`, `pure`, `bind`, `replicate`, and
   `reverse`.
 * Additional functions defined in terms of these: `leftpad`, `rightPad`, and `reduceOption`.
 * Operations using indexes: `mapIdx`.
@@ -38,14 +38,14 @@ The operations are organized as follow:
 * Sublists: `take`, `drop`, `takeWhile`, `dropWhile`, `partition`, `dropLast`,
   `isPrefixOf`, `isPrefixOf?`, `isSuffixOf`, `isSuffixOf?`, `Subset`, `Sublist`,
   `rotateLeft` and `rotateRight`.
-* Manipulating elements: `replace`, `modify`, `insert`, `insertIdx`, `erase`, `eraseP`, `eraseIdx`.
+* Manipulating elements: `replace`, `insert`, `erase`, `eraseP`, `eraseIdx`.
 * Finding elements: `find?`, `findSome?`, `findIdx`, `indexOf`, `findIdx?`, `indexOf?`,
  `countP`, `count`, and `lookup`.
 * Logic: `any`, `all`, `or`, and `and`.
 * Zippers: `zipWith`, `zip`, `zipWithAll`, and `unzip`.
 * Ranges and enumeration: `range`, `iota`, `enumFrom`, and `enum`.
 * Minima and maxima: `min?` and `max?`.
-* Other functions: `intersperse`, `intercalate`, `eraseDups`, `eraseReps`, `span`, `splitBy`,
+* Other functions: `intersperse`, `intercalate`, `eraseDups`, `eraseReps`, `span`, `groupBy`,
   `removeAll`
   (currently these functions are mostly only used in meta code,
   and do not have API suitable for verification).
@@ -122,11 +122,6 @@ protected def beq [BEq α] : List α → List α → Bool
   | a::as, b::bs => a == b && List.beq as bs
   | _,     _     => false
 
-@[simp] theorem beq_nil_nil [BEq α] : List.beq ([] : List α) ([] : List α) = true := rfl
-@[simp] theorem beq_cons_nil [BEq α] (a : α) (as : List α) : List.beq (a::as) [] = false := rfl
-@[simp] theorem beq_nil_cons [BEq α] (a : α) (as : List α) : List.beq [] (a::as) = false := rfl
-theorem beq_cons₂ [BEq α] (a b : α) (as bs : List α) : List.beq (a::as) (b::bs) = (a == b && List.beq as bs) := rfl
-
 instance [BEq α] : BEq (List α) := ⟨List.beq⟩
 
 instance [BEq α] [LawfulBEq α] : LawfulBEq (List α) where
@@ -1113,50 +1108,12 @@ theorem replace_cons [BEq α] {a : α} :
     (a::as).replace b c = match b == a with | true => c::as | false => a :: replace as b c :=
   rfl
 
-/-! ### modify -/
-
-/--
-Apply a function to the nth tail of `l`. Returns the input without
-using `f` if the index is larger than the length of the List.
-```
-modifyTailIdx f 2 [a, b, c] = [a, b] ++ f [c]
-```
--/
-@[simp] def modifyTailIdx (f : List α → List α) : Nat → List α → List α
-  | 0, l => f l
-  | _+1, [] => []
-  | n+1, a :: l => a :: modifyTailIdx f n l
-
-/-- Apply `f` to the head of the list, if it exists. -/
-@[inline] def modifyHead (f : α → α) : List α → List α
-  | [] => []
-  | a :: l => f a :: l
-
-@[simp] theorem modifyHead_nil (f : α → α) : [].modifyHead f = [] := by rw [modifyHead]
-@[simp] theorem modifyHead_cons (a : α) (l : List α) (f : α → α) :
-    (a :: l).modifyHead f = f a :: l := by rw [modifyHead]
-
-/--
-Apply `f` to the nth element of the list, if it exists, replacing that element with the result.
--/
-def modify (f : α → α) : Nat → List α → List α :=
-  modifyTailIdx (modifyHead f)
-
 /-! ### insert -/
 
 /-- Inserts an element into a list without duplication. -/
 @[inline] protected def insert [BEq α] (a : α) (l : List α) : List α :=
   if l.elem a then l else a :: l
 
-/--
-`insertIdx n a l` inserts `a` into the list `l` after the first `n` elements of `l`
-```
-insertIdx 2 1 [1, 2, 3, 4] = [1, 2, 1, 3, 4]
-```
--/
-def insertIdx (n : Nat) (a : α) : List α → List α :=
-  modifyTailIdx (cons a) n
-
 /-! ### erase -/
 
 /--
@@ -1461,15 +1418,11 @@ def sum {α} [Add α] [Zero α] : List α → α :=
 @[simp] theorem sum_cons [Add α] [Zero α] {a : α} {l : List α} : (a::l).sum = a + l.sum := rfl
 
 /-- Sum of a list of natural numbers. -/
-@[deprecated List.sum (since := "2024-10-17")]
+-- We intend to subsequently deprecate this in favor of `List.sum`.
 protected def _root_.Nat.sum (l : List Nat) : Nat := l.foldr (·+·) 0
 
-set_option linter.deprecated false in
-@[simp, deprecated sum_nil (since := "2024-10-17")]
-theorem _root_.Nat.sum_nil : Nat.sum ([] : List Nat) = 0 := rfl
-set_option linter.deprecated false in
-@[simp, deprecated sum_cons (since := "2024-10-17")]
-theorem _root_.Nat.sum_cons (a : Nat) (l : List Nat) :
+@[simp] theorem _root_.Nat.sum_nil : Nat.sum ([] : List Nat) = 0 := rfl
+@[simp] theorem _root_.Nat.sum_cons (a : Nat) (l : List Nat) :
     Nat.sum (a::l) = a + Nat.sum l := rfl
 
 /-! ### range -/
@@ -1648,23 +1601,23 @@ where
     | true  => loop as (a::rs)
     | false => (rs.reverse, a::as)
 
-/-! ### splitBy -/
+/-! ### groupBy -/
 
 /--
-`O(|l|)`. `splitBy R l` splits `l` into chains of elements
+`O(|l|)`. `groupBy R l` splits `l` into chains of elements
 such that adjacent elements are related by `R`.
 
-* `splitBy (·==·) [1, 1, 2, 2, 2, 3, 2] = [[1, 1], [2, 2, 2], [3], [2]]`
-* `splitBy (·<·) [1, 2, 5, 4, 5, 1, 4] = [[1, 2, 5], [4, 5], [1, 4]]`
+* `groupBy (·==·) [1, 1, 2, 2, 2, 3, 2] = [[1, 1], [2, 2, 2], [3], [2]]`
+* `groupBy (·<·) [1, 2, 5, 4, 5, 1, 4] = [[1, 2, 5], [4, 5], [1, 4]]`
 -/
-@[specialize] def splitBy (R : α → α → Bool) : List α → List (List α)
+@[specialize] def groupBy (R : α → α → Bool) : List α → List (List α)
   | []    => []
   | a::as => loop as a [] []
 where
   /--
-  The arguments of `splitBy.loop l ag g gs` represent the following:
+  The arguments of `groupBy.loop l ag g gs` represent the following:
 
-  - `l : List α` are the elements which we still need to split.
+  - `l : List α` are the elements which we still need to group.
   - `ag : α` is the previous element for which a comparison was performed.
   - `g : List α` is the group currently being assembled, in **reverse order**.
   - `gs : List (List α)` is all of the groups that have been completed, in **reverse order**.
@@ -1675,8 +1628,6 @@ where
     | false => loop as a [] ((ag::g).reverse::gs)
   | [], ag, g, gs => ((ag::g).reverse::gs).reverse
 
-@[deprecated splitBy (since := "2024-10-30"), inherit_doc splitBy] abbrev groupBy := @splitBy
-
 /-! ### removeAll -/
 
 /-- `O(|xs|)`. Computes the "set difference" of lists,

src/Init/Data/List/BasicAux.lean

@@ -232,8 +232,7 @@ theorem sizeOf_get [SizeOf α] (as : List α) (i : Fin as.length) : sizeOf (as.g
     apply Nat.lt_trans ih
     simp_arith
 
-theorem le_antisymm [LT α] [s : Std.Antisymm (¬ · < · : α → α → Prop)]
-    {as bs : List α} (h₁ : as ≤ bs) (h₂ : bs ≤ as) : as = bs :=
+theorem le_antisymm [LT α] [s : Antisymm (¬ · < · : α → α → Prop)] {as bs : List α} (h₁ : as ≤ bs) (h₂ : bs ≤ as) : as = bs :=
   match as, bs with
   | [],    []    => rfl
   | [],    _::_ => False.elim <| h₂ (List.lt.nil ..)
@@ -249,8 +248,7 @@ theorem le_antisymm [LT α] [s : Std.Antisymm (¬ · < · : α → α → Prop)]
         have : a = b := s.antisymm hab hba
         simp [this, ih]
 
-instance [LT α] [Std.Antisymm (¬ · < · : α → α → Prop)] :
-    Std.Antisymm (· ≤ · : List α → List α → Prop) where
+instance [LT α] [Antisymm (¬ · < · : α → α → Prop)] : Antisymm (· ≤ · : List α → List α → Prop) where
   antisymm h₁ h₂ := le_antisymm h₁ h₂
 
 end List

src/Init/Data/List/Control.lean

@@ -5,8 +5,6 @@ Author: Leonardo de Moura
 -/
 prelude
 import Init.Control.Basic
-import Init.Control.Id
-import Init.Control.Lawful
 import Init.Data.List.Basic
 
 namespace List
@@ -209,16 +207,6 @@ def findM? {m : Type → Type u} [Monad m] {α : Type} (p : α → m Bool) : Lis
     | true  => pure (some a)
     | false => findM? p as
 
-@[simp]
-theorem findM?_id (p : α → Bool) (as : List α) : findM? (m := Id) p as = as.find? p := by
-  induction as with
-  | nil => rfl
-  | cons a as ih =>
-    simp only [findM?, find?]
-    cases p a with
-    | true  => rfl
-    | false => rw [ih]; rfl
-
 @[specialize]
 def findSomeM? {m : Type u → Type v} [Monad m] {α : Type w} {β : Type u} (f : α → m (Option β)) : List α → m (Option β)
   | []    => pure none
@@ -227,27 +215,26 @@ def findSomeM? {m : Type u → Type v} [Monad m] {α : Type w} {β : Type u} (f
     | some b => pure (some b)
     | none   => findSomeM? f as
 
-@[simp]
-theorem findSomeM?_id (f : α → Option β) (as : List α) : findSomeM? (m := Id) f as = as.findSome? f := by
-  induction as with
-  | nil => rfl
-  | cons a as ih =>
-    simp only [findSomeM?, findSome?]
-    cases f a with
-    | some b => rfl
-    | none   => rw [ih]; rfl
+@[inline] protected def forIn {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : List α) (init : β) (f : α → β → m (ForInStep β)) : m β :=
+  let rec @[specialize] loop
+    | [], b    => pure b
+    | a::as, b => do
+      match (← f a b) with
+      | ForInStep.done b  => pure b
+      | ForInStep.yield b => loop as b
+  loop as init
 
-theorem findM?_eq_findSomeM? [Monad m] [LawfulMonad m] (p : α → m Bool) (as : List α) :
-    as.findM? p = as.findSomeM? fun a => return if (← p a) then some a else none := by
-  induction as with
-  | nil => rfl
-  | cons a as ih =>
-    simp only [findM?, findSomeM?]
-    simp [ih]
-    congr
-    apply funext
-    intro b
-    cases b <;> simp
+instance : ForIn m (List α) α where
+  forIn := List.forIn
+
+@[simp] theorem forIn_eq_forIn [Monad m] : @List.forIn α β m _ = forIn := rfl
+
+@[simp] theorem forIn_nil [Monad m] (f : α → β → m (ForInStep β)) (b : β) : forIn [] b f = pure b :=
+  rfl
+
+@[simp] theorem forIn_cons [Monad m] (f : α → β → m (ForInStep β)) (a : α) (as : List α) (b : β)
+    : forIn (a::as) b f = f a b >>= fun | ForInStep.done b => pure b | ForInStep.yield b => forIn as b f :=
+  rfl
 
 @[inline] protected def forIn' {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : List α) (init : β) (f : (a : α) → a ∈ as → β → m (ForInStep β)) : m β :=
   let rec @[specialize] loop : (as' : List α) → (b : β) → Exists (fun bs => bs ++ as' = as) → m β
@@ -267,15 +254,14 @@ theorem findM?_eq_findSomeM? [Monad m] [LawfulMonad m] (p : α → m Bool) (as :
 instance : ForIn' m (List α) α inferInstance where
   forIn' := List.forIn'
 
--- No separate `ForIn` instance is required because it can be derived from `ForIn'`.
-
-@[simp] theorem forIn'_eq_forIn' [Monad m] : @List.forIn' α β m _ = forIn' := rfl
-
-@[simp] theorem forIn'_nil [Monad m] (f : (a : α) → a ∈ [] → β → m (ForInStep β)) (b : β) : forIn' [] b f = pure b :=
-  rfl
-
-@[simp] theorem forIn_nil [Monad m] (f : α → β → m (ForInStep β)) (b : β) : forIn [] b f = pure b :=
-  rfl
+@[simp] theorem forIn'_eq_forIn {α : Type u} {β : Type v} {m : Type v → Type w} [Monad m] (as : List α) (init : β) (f : α → β → m (ForInStep β)) : forIn' as init (fun a _ b => f a b) = forIn as init f := by
+  simp [forIn', forIn, List.forIn, List.forIn']
+  have : ∀ cs h, List.forIn'.loop cs (fun a _ b => f a b) as init h = List.forIn.loop f as init := by
+    intro cs h
+    induction as generalizing cs init with
+    | nil => intros; rfl
+    | cons a as ih => intros; simp [List.forIn.loop, List.forIn'.loop, ih]
+  apply this
 
 instance : ForM m (List α) α where
   forM := List.forM

src/Init/Data/List/Count.lean

@@ -153,7 +153,7 @@ theorem countP_filterMap (p : β → Bool) (f : α → Option β) (l : List α)
   simp only [length_filterMap_eq_countP]
   congr
   ext a
-  simp +contextual [Option.getD_eq_iff, Option.isSome_eq_isSome]
+  simp (config := { contextual := true }) [Option.getD_eq_iff, Option.isSome_eq_isSome]
 
 @[simp] theorem countP_flatten (l : List (List α)) :
     countP p l.flatten = (l.map (countP p)).sum := by
@@ -315,7 +315,7 @@ theorem replicate_count_eq_of_count_eq_length {l : List α} (h : count a l = len
 theorem count_le_count_map [DecidableEq β] (l : List α) (f : α → β) (x : α) :
     count x l ≤ count (f x) (map f l) := by
   rw [count, count, countP_map]
-  apply countP_mono_left; simp +contextual
+  apply countP_mono_left; simp (config := { contextual := true })
 
 theorem count_filterMap {α} [BEq β] (b : β) (f : α → Option β) (l : List α) :
     count b (filterMap f l) = countP (fun a => f a == some b) l := by

src/Init/Data/List/Find.lean

@@ -10,8 +10,7 @@ import Init.Data.List.Sublist
 import Init.Data.List.Range
 
 /-!
-Lemmas about `List.findSome?`, `List.find?`, `List.findIdx`, `List.findIdx?`, `List.indexOf`,
-and `List.lookup`.
+# Lemmas about `List.findSome?`, `List.find?`, `List.findIdx`, `List.findIdx?`, and `List.indexOf`.
 -/
 
 namespace List
@@ -96,22 +95,22 @@ theorem findSome?_eq_some_iff {f : α → Option β} {l : List α} {b : β} :
     · simp only [Option.guard_eq_none] at h
       simp [ih, h]
 
-@[simp] theorem head?_filterMap (f : α → Option β) (l : List α) : (l.filterMap f).head? = l.findSome? f := by
+@[simp] theorem filterMap_head? (f : α → Option β) (l : List α) : (l.filterMap f).head? = l.findSome? f := by
   induction l with
   | nil => simp
   | cons x xs ih =>
     simp only [filterMap_cons, findSome?_cons]
     split <;> simp [*]
 
-@[simp] theorem head_filterMap (f : α → Option β) (l : List α) (h) :
-    (l.filterMap f).head h = (l.findSome? f).get (by simp_all [Option.isSome_iff_ne_none]) := by
+@[simp] theorem filterMap_head (f : α → Option β) (l : List α) (h) :
+    (l.filterMap f).head h = (l.findSome? f).get (by simp_all [Option.isSome_iff_ne_none])  := by
   simp [head_eq_iff_head?_eq_some]
 
-@[simp] theorem getLast?_filterMap (f : α → Option β) (l : List α) : (l.filterMap f).getLast? = l.reverse.findSome? f := by
+@[simp] theorem filterMap_getLast? (f : α → Option β) (l : List α) : (l.filterMap f).getLast? = l.reverse.findSome? f := by
   rw [getLast?_eq_head?_reverse]
   simp [← filterMap_reverse]
 
-@[simp] theorem getLast_filterMap (f : α → Option β) (l : List α) (h) :
+@[simp] theorem filterMap_getLast (f : α → Option β) (l : List α) (h) :
     (l.filterMap f).getLast h = (l.reverse.findSome? f).get (by simp_all [Option.isSome_iff_ne_none]) := by
   simp [getLast_eq_iff_getLast_eq_some]
 
@@ -180,7 +179,7 @@ theorem IsPrefix.findSome?_eq_some {l₁ l₂ : List α} {f : α → Option β}
     List.findSome? f l₁ = some b → List.findSome? f l₂ = some b := by
   rw [IsPrefix] at h
   obtain ⟨t, rfl⟩ := h
-  simp +contextual [findSome?_append]
+  simp (config := {contextual := true}) [findSome?_append]
 
 theorem IsPrefix.findSome?_eq_none {l₁ l₂ : List α} {f : α → Option β} (h : l₁ <+: l₂) :
     List.findSome? f l₂ = none → List.findSome? f l₁ = none :=
@@ -207,8 +206,7 @@ theorem IsInfix.findSome?_eq_none {l₁ l₂ : List α} {f : α → Option β} (
 @[simp] theorem find?_eq_none : find? p l = none ↔ ∀ x ∈ l, ¬ p x := by
   induction l <;> simp [find?_cons]; split <;> simp [*]
 
-theorem find?_eq_some_iff_append :
-    xs.find? p = some b ↔ p b ∧ ∃ as bs, xs = as ++ b :: bs ∧ ∀ a ∈ as, !p a := by
+theorem find?_eq_some : xs.find? p = some b ↔ p b ∧ ∃ as bs, xs = as ++ b :: bs ∧ ∀ a ∈ as, !p a := by
   induction xs with
   | nil => simp
   | cons x xs ih =>
@@ -244,9 +242,6 @@ theorem find?_eq_some_iff_append :
           cases h₁
           simp
 
-@[deprecated find?_eq_some_iff_append (since := "2024-11-06")]
-abbrev find?_eq_some := @find?_eq_some_iff_append
-
 @[simp]
 theorem find?_cons_eq_some : (a :: xs).find? p = some b ↔ (p a ∧ a = b) ∨ (!p a ∧ xs.find? p = some b) := by
   rw [find?_cons]
@@ -292,18 +287,18 @@ theorem get_find?_mem (xs : List α) (p : α → Bool) (h) : (xs.find? p).get h
     · simp only [find?_cons]
       split <;> simp_all
 
-@[simp] theorem head?_filter (p : α → Bool) (l : List α) : (l.filter p).head? = l.find? p := by
-  rw [← filterMap_eq_filter, head?_filterMap, findSome?_guard]
+@[simp] theorem filter_head? (p : α → Bool) (l : List α) : (l.filter p).head? = l.find? p := by
+  rw [← filterMap_eq_filter, filterMap_head?, findSome?_guard]
 
-@[simp] theorem head_filter (p : α → Bool) (l : List α) (h) :
+@[simp] theorem filter_head (p : α → Bool) (l : List α) (h) :
     (l.filter p).head h = (l.find? p).get (by simp_all [Option.isSome_iff_ne_none]) := by
   simp [head_eq_iff_head?_eq_some]
 
-@[simp] theorem getLast?_filter (p : α → Bool) (l : List α) : (l.filter p).getLast? = l.reverse.find? p := by
+@[simp] theorem filter_getLast? (p : α → Bool) (l : List α) : (l.filter p).getLast? = l.reverse.find? p := by
   rw [getLast?_eq_head?_reverse]
   simp [← filter_reverse]
 
-@[simp] theorem getLast_filter (p : α → Bool) (l : List α) (h) :
+@[simp] theorem filter_getLast (p : α → Bool) (l : List α) (h) :
     (l.filter p).getLast h = (l.reverse.find? p).get (by simp_all [Option.isSome_iff_ne_none]) := by
   simp [getLast_eq_iff_getLast_eq_some]
 
@@ -352,7 +347,7 @@ theorem find?_flatten_eq_some {xs : List (List α)} {p : α → Bool} {a : α} :
     xs.flatten.find? p = some a ↔
       p a ∧ ∃ as ys zs bs, xs = as ++ (ys ++ a :: zs) :: bs ∧
         (∀ a ∈ as, ∀ x ∈ a, !p x) ∧ (∀ x ∈ ys, !p x) := by
-  rw [find?_eq_some_iff_append]
+  rw [find?_eq_some]
   constructor
   · rintro ⟨h, ⟨ys, zs, h₁, h₂⟩⟩
     refine ⟨h, ?_⟩
@@ -441,7 +436,7 @@ theorem IsPrefix.find?_eq_some {l₁ l₂ : List α} {p : α → Bool} (h : l₁
     List.find? p l₁ = some b → List.find? p l₂ = some b := by
   rw [IsPrefix] at h
   obtain ⟨t, rfl⟩ := h
-  simp +contextual [find?_append]
+  simp (config := {contextual := true}) [find?_append]
 
 theorem IsPrefix.find?_eq_none {l₁ l₂ : List α} {p : α → Bool} (h : l₁ <+: l₂) :
     List.find? p l₂ = none → List.find? p l₁ = none :=
@@ -567,7 +562,7 @@ theorem not_of_lt_findIdx {p : α → Bool} {xs : List α} {i : Nat} (h : i < xs
     | inr e =>
       have ipm := Nat.succ_pred_eq_of_pos e
       have ilt := Nat.le_trans ho (findIdx_le_length p)
-      simp +singlePass only [← ipm, getElem_cons_succ]
+      simp (config := { singlePass := true }) only [← ipm, getElem_cons_succ]
       rw [← ipm, Nat.succ_lt_succ_iff] at h
       simpa using ih h
 
@@ -600,14 +595,15 @@ theorem findIdx_eq {p : α → Bool} {xs : List α} {i : Nat} (h : i < xs.length
 
 theorem findIdx_append (p : α → Bool) (l₁ l₂ : List α) :
     (l₁ ++ l₂).findIdx p =
-      if l₁.findIdx p < l₁.length then l₁.findIdx p else l₂.findIdx p + l₁.length := by
+      if ∃ x, x ∈ l₁ ∧ p x = true then l₁.findIdx p else l₂.findIdx p + l₁.length := by
   induction l₁ with
   | nil => simp
   | cons x xs ih =>
     simp only [findIdx_cons, length_cons, cons_append]
     by_cases h : p x
     · simp [h]
-    · simp only [h, ih, cond_eq_if, Bool.false_eq_true, ↓reduceIte, add_one_lt_add_one_iff]
+    · simp only [h, ih, cond_eq_if, Bool.false_eq_true, ↓reduceIte, mem_cons, exists_eq_or_imp,
+        false_or]
       split <;> simp [Nat.add_assoc]
 
 theorem IsPrefix.findIdx_le {l₁ l₂ : List α} {p : α → Bool} (h : l₁ <+: l₂) :

src/Init/Data/List/Impl.lean

@@ -23,7 +23,7 @@ namespace List
 The following operations are already tail-recursive, and do not need `@[csimp]` replacements:
 `get`, `foldl`, `beq`, `isEqv`, `reverse`, `elem` (and hence `contains`), `drop`, `dropWhile`,
 `partition`, `isPrefixOf`, `isPrefixOf?`, `find?`, `findSome?`, `lookup`, `any` (and hence `or`),
-`all` (and hence `and`) , `range`, `eraseDups`, `eraseReps`, `span`, `splitBy`.
+`all` (and hence `and`) , `range`, `eraseDups`, `eraseReps`, `span`, `groupBy`.
 
 The following operations are still missing `@[csimp]` replacements:
 `concat`, `zipWithAll`.
@@ -38,7 +38,7 @@ The following operations were already given `@[csimp]` replacements in `Init/Dat
 
 The following operations are given `@[csimp]` replacements below:
 `set`, `filterMap`, `foldr`, `append`, `bind`, `join`,
-`take`, `takeWhile`, `dropLast`, `replace`, `modify`, `insertIdx`, `erase`, `eraseIdx`, `zipWith`,
+`take`, `takeWhile`, `dropLast`, `replace`, `erase`, `eraseIdx`, `zipWith`,
 `enumFrom`, and `intercalate`.
 
 -/
@@ -197,41 +197,6 @@ The following operations are given `@[csimp]` replacements below:
     · simp [*]
     · intro h; rw [IH] <;> simp_all
 
-/-! ### modify -/
-
-/-- Tail-recursive version of `modify`. -/
-def modifyTR (f : α → α) (n : Nat) (l : List α) : List α := go l n #[] where
-  /-- Auxiliary for `modifyTR`: `modifyTR.go f l n acc = acc.toList ++ modify f n l`. -/
-  go : List α → Nat → Array α → List α
-  | [], _, acc => acc.toList
-  | a :: l, 0, acc => acc.toListAppend (f a :: l)
-  | a :: l, n+1, acc => go l n (acc.push a)
-
-theorem modifyTR_go_eq : ∀ l n, modifyTR.go f l n acc = acc.toList ++ modify f n l
-  | [], n => by cases n <;> simp [modifyTR.go, modify]
-  | a :: l, 0 => by simp [modifyTR.go, modify]
-  | a :: l, n+1 => by simp [modifyTR.go, modify, modifyTR_go_eq l]
-
-@[csimp] theorem modify_eq_modifyTR : @modify = @modifyTR := by
-  funext α f n l; simp [modifyTR, modifyTR_go_eq]
-
-/-! ### insertIdx -/
-
-/-- Tail-recursive version of `insertIdx`. -/
-@[inline] def insertIdxTR (n : Nat) (a : α) (l : List α) : List α := go n l #[] where
-  /-- Auxiliary for `insertIdxTR`: `insertIdxTR.go a n l acc = acc.toList ++ insertIdx n a l`. -/
-  go : Nat → List α → Array α → List α
-  | 0, l, acc => acc.toListAppend (a :: l)
-  | _, [], acc => acc.toList
-  | n+1, a :: l, acc => go n l (acc.push a)
-
-theorem insertIdxTR_go_eq : ∀ n l, insertIdxTR.go a n l acc = acc.toList ++ insertIdx n a l
-  | 0, l | _+1, [] => by simp [insertIdxTR.go, insertIdx]
-  | n+1, a :: l => by simp [insertIdxTR.go, insertIdx, insertIdxTR_go_eq n l]
-
-@[csimp] theorem insertIdx_eq_insertIdxTR : @insertIdx = @insertIdxTR := by
-  funext α f n l; simp [insertIdxTR, insertIdxTR_go_eq]
-
 /-! ### erase -/
 
 /-- Tail recursive version of `List.erase`. -/

src/Init/Data/List/Lemmas.lean

@@ -492,6 +492,10 @@ theorem getElem?_of_mem {a} {l : List α} (h : a ∈ l) : ∃ n : Nat, l[n]? = s
 theorem get?_of_mem {a} {l : List α} (h : a ∈ l) : ∃ n, l.get? n = some a :=
   let ⟨⟨n, _⟩, e⟩ := get_of_mem h; ⟨n, e ▸ get?_eq_get _⟩
 
+@[simp] theorem getElem_mem : ∀ {l : List α} {n} (h : n < l.length), l[n]'h ∈ l
+  | _ :: _, 0, _ => .head ..
+  | _ :: l, _+1, _ => .tail _ (getElem_mem (l := l) ..)
+
 theorem get_mem : ∀ (l : List α) n h, get l ⟨n, h⟩ ∈ l
   | _ :: _, 0, _ => .head ..
   | _ :: l, _+1, _ => .tail _ (get_mem l ..)
@@ -863,30 +867,14 @@ theorem foldr_map (f : α₁ → α₂) (g : α₂ → β → β) (l : List α
     (l.map f).foldr g init = l.foldr (fun x y => g (f x) y) init := by
   induction l generalizing init <;> simp [*]
 
-theorem foldl_filterMap (f : α → Option β) (g : γ → β → γ) (l : List α) (init : γ) :
-    (l.filterMap f).foldl g init = l.foldl (fun x y => match f y with | some b => g x b | none => x) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filterMap_cons, foldl_cons]
-    cases f a <;> simp [ih]
-
-theorem foldr_filterMap (f : α → Option β) (g : β → γ → γ) (l : List α) (init : γ) :
-    (l.filterMap f).foldr g init = l.foldr (fun x y => match f x with | some b => g b y | none => y) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filterMap_cons, foldr_cons]
-    cases f a <;> simp [ih]
-
-theorem foldl_map' (g : α → β) (f : α → α → α) (f' : β → β → β) (a : α) (l : List α)
+theorem foldl_map' {α β : Type u} (g : α → β) (f : α → α → α) (f' : β → β → β) (a : α) (l : List α)
     (h : ∀ x y, f' (g x) (g y) = g (f x y)) :
     (l.map g).foldl f' (g a) = g (l.foldl f a) := by
   induction l generalizing a
   · simp
   · simp [*, h]
 
-theorem foldr_map' (g : α → β) (f : α → α → α) (f' : β → β → β) (a : α) (l : List α)
+theorem foldr_map' {α β : Type u} (g : α → β) (f : α → α → α) (f' : β → β → β) (a : α) (l : List α)
     (h : ∀ x y, f' (g x) (g y) = g (f x y)) :
     (l.map g).foldr f' (g a) = g (l.foldr f a) := by
   induction l generalizing a
@@ -999,21 +987,6 @@ theorem foldr_rel {l : List α} {f g : α → β → β} {a b : β} (r : β →
     · simp
     · exact ih h fun a m c c' h => h' _ (by simp_all) _ _ h
 
-@[simp] theorem foldl_add_const (l : List α) (a b : Nat) :
-    l.foldl (fun x _ => x + a) b = b + a * l.length := by
-  induction l generalizing b with
-  | nil => simp
-  | cons y l ih =>
-    simp only [foldl_cons, ih, length_cons, Nat.mul_add, Nat.mul_one, Nat.add_assoc,
-      Nat.add_comm a]
-
-@[simp] theorem foldr_add_const (l : List α) (a b : Nat) :
-    l.foldr (fun _ x => x + a) b = b + a * l.length := by
-  induction l generalizing b with
-  | nil => simp
-  | cons y l ih =>
-    simp only [foldr_cons, ih, length_cons, Nat.mul_add, Nat.mul_one, Nat.add_assoc]
-
 /-! ### getLast -/
 
 theorem getLast_eq_getElem : ∀ (l : List α) (h : l ≠ []),
@@ -1045,7 +1018,7 @@ theorem getLast_eq_getLastD (a l h) : @getLast α (a::l) h = getLastD l a := by
 
 @[simp] theorem getLast_singleton (a h) : @getLast α [a] h = a := rfl
 
-theorem getLast!_cons_eq_getLastD [Inhabited α] : @getLast! α _ (a::l) = getLastD l a := by
+theorem getLast!_cons [Inhabited α] : @getLast! α _ (a::l) = getLastD l a := by
   simp [getLast!, getLast_eq_getLastD]
 
 @[simp] theorem getLast_mem : ∀ {l : List α} (h : l ≠ []), getLast l h ∈ l
@@ -1074,6 +1047,9 @@ theorem get_cons_length (x : α) (xs : List α) (n : Nat) (h : n = xs.length) :
 
 @[simp] theorem getLast?_singleton (a : α) : getLast? [a] = a := rfl
 
+theorem getLast!_of_getLast? [Inhabited α] : ∀ {l : List α}, getLast? l = some a → getLast! l = a
+  | _ :: _, rfl => rfl
+
 theorem getLast?_eq_getLast : ∀ l h, @getLast? α l = some (getLast l h)
   | [], h => nomatch h rfl
   | _ :: _, _ => rfl
@@ -1107,26 +1083,6 @@ theorem getLast?_concat (l : List α) : getLast? (l ++ [a]) = some a := by
 theorem getLastD_concat (a b l) : @getLastD α (l ++ [b]) a = b := by
   rw [getLastD_eq_getLast?, getLast?_concat]; rfl
 
-/-! ### getLast! -/
-
-theorem getLast!_nil [Inhabited α] : ([] : List α).getLast! = default := rfl
-
-@[simp] theorem getLast!_eq_getLast?_getD [Inhabited α] {l : List α} : getLast! l = (getLast? l).getD default := by
-  cases l with
-  | nil => simp [getLast!_nil]
-  | cons _ _ => simp [getLast!, getLast?_eq_getLast]
-
-theorem getLast!_of_getLast? [Inhabited α] : ∀ {l : List α}, getLast? l = some a → getLast! l = a
-  | _ :: _, rfl => rfl
-
-theorem getLast!_eq_getElem! [Inhabited α] {l : List α} : l.getLast! = l[l.length - 1]! := by
-  cases l with
-  | nil => simp
-  | cons _ _ =>
-    apply getLast!_of_getLast?
-    rw [getElem!_pos, getElem_cons_length (h := by simp)]
-    rfl
-
 /-! ## Head and tail -/
 
 /-! ### head -/
@@ -1493,22 +1449,6 @@ theorem forall_mem_filter {l : List α} {p : α → Bool} {P : α → Prop} :
   | [] => rfl
   | a :: l => by by_cases hp : p a <;> by_cases hq : q a <;> simp [hp, hq, filter_filter _ l]
 
-theorem foldl_filter (p : α → Bool) (f : β → α → β) (l : List α) (init : β) :
-    (l.filter p).foldl f init = l.foldl (fun x y => if p y then f x y else x) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filter_cons, foldl_cons]
-    split <;> simp [ih]
-
-theorem foldr_filter (p : α → Bool) (f : α → β → β) (l : List α) (init : β) :
-    (l.filter p).foldr f init = l.foldr (fun x y => if p x then f x y else y) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filter_cons, foldr_cons]
-    split <;> simp [ih]
-
 theorem filter_map (f : β → α) (l : List β) : filter p (map f l) = map f (filter (p ∘ f) l) := by
   induction l with
   | nil => rfl
@@ -2752,12 +2692,6 @@ theorem flatMap_reverse {β} (l : List α) (f : α → List β) : (l.reverse.fla
     l.reverse.foldr f b = l.foldl (fun x y => f y x) b :=
   (foldl_reverse ..).symm.trans <| by simp
 
-theorem foldl_eq_foldr_reverse (l : List α) (f : β → α → β) (b) :
-    l.foldl f b = l.reverse.foldr (fun x y => f y x) b := by simp
-
-theorem foldr_eq_foldl_reverse (l : List α) (f : α → β → β) (b) :
-    l.foldr f b = l.reverse.foldl (fun x y => f y x) b := by simp
-
 @[simp] theorem reverse_replicate (n) (a : α) : reverse (replicate n a) = replicate n a :=
   eq_replicate_iff.2
     ⟨by rw [length_reverse, length_replicate],
@@ -2901,10 +2835,6 @@ theorem contains_iff_exists_mem_beq [BEq α] {l : List α} {a : α} :
     l.contains a ↔ ∃ a' ∈ l, a == a' := by
   induction l <;> simp_all
 
-theorem contains_iff_mem [BEq α] [LawfulBEq α] {l : List α} {a : α} :
-    l.contains a ↔ a ∈ l := by
-  simp
-
 /-! ## Sublists -/
 
 /-! ### partition
@@ -3390,7 +3320,7 @@ theorem all_eq_not_any_not (l : List α) (p : α → Bool) : l.all p = !l.any (!
 
 @[simp] theorem all_replicate {n : Nat} {a : α} :
     (replicate n a).all f = if n = 0 then true else f a := by
-  cases n <;> simp +contextual [replicate_succ]
+  cases n <;> simp (config := {contextual := true}) [replicate_succ]
 
 @[simp] theorem any_insert [BEq α] [LawfulBEq α] {l : List α} {a : α} :
     (l.insert a).any f = (f a || l.any f) := by

src/Init/Data/List/MapIdx.lean

@@ -7,9 +7,6 @@ Authors: Kim Morrison, Mario Carneiro
 prelude
 import Init.Data.Array.Lemmas
 import Init.Data.List.Nat.Range
-import Init.Data.List.OfFn
-import Init.Data.Fin.Lemmas
-import Init.Data.Option.Attach
 
 namespace List
 
@@ -17,21 +14,8 @@ namespace List
 
 /-! ### mapIdx -/
 
-
 /--
-Given a list `as = [a₀, a₁, ...]` function `f : Fin as.length → α → β`, returns the list
-`[f 0 a₀, f 1 a₁, ...]`.
--/
-@[inline] def mapFinIdx (as : List α) (f : Fin as.length → α → β) : List β := go as #[] (by simp) where
-  /-- Auxiliary for `mapFinIdx`:
-  `mapFinIdx.go [a₀, a₁, ...] acc = acc.toList ++ [f 0 a₀, f 1 a₁, ...]` -/
-  @[specialize] go : (bs : List α) → (acc : Array β) → bs.length + acc.size = as.length → List β
-  | [], acc, h => acc.toList
-  | a :: as, acc, h =>
-    go as (acc.push (f ⟨acc.size, by simp at h; omega⟩ a)) (by simp at h ⊢; omega)
-
-/--
-Given a function `f : Nat → α → β` and `as : List α`, `as = [a₀, a₁, ...]`, returns the list
+Given a function `f : Nat → α → β` and `as : list α`, `as = [a₀, a₁, ...]`, returns the list
 `[f 0 a₀, f 1 a₁, ...]`.
 -/
 @[inline] def mapIdx (f : Nat → α → β) (as : List α) : List β := go as #[] where
@@ -41,177 +25,34 @@ Given a function `f : Nat → α → β` and `as : List α`, `as = [a₀, a₁,
   | [], acc => acc.toList
   | a :: as, acc => go as (acc.push (f acc.size a))
 
-/-! ### mapFinIdx -/
-
-@[simp]
-theorem mapFinIdx_nil {f : Fin 0 → α → β} : mapFinIdx [] f = [] :=
-  rfl
-
-@[simp] theorem length_mapFinIdx_go :
-    (mapFinIdx.go as f bs acc h).length = as.length := by
-  induction bs generalizing acc with
-  | nil => simpa using h
-  | cons _ _ ih => simp [mapFinIdx.go, ih]
-
-@[simp] theorem length_mapFinIdx {as : List α} {f : Fin as.length → α → β} :
-    (as.mapFinIdx f).length = as.length := by
-  simp [mapFinIdx, length_mapFinIdx_go]
-
-theorem getElem_mapFinIdx_go {as : List α} {f : Fin as.length → α → β} {i : Nat} {h} {w} :
-    (mapFinIdx.go as f bs acc h)[i] =
-      if w' : i < acc.size then acc[i] else f ⟨i, by simp at w; omega⟩ (bs[i - acc.size]'(by simp at w; omega)) := by
-  induction bs generalizing acc with
-  | nil =>
-    simp only [length_mapFinIdx_go, length_nil, Nat.zero_add] at w h
-    simp only [mapFinIdx.go, Array.getElem_toList]
-    rw [dif_pos]
-  | cons _ _ ih =>
-    simp [mapFinIdx.go]
-    rw [ih]
-    simp
-    split <;> rename_i h₁ <;> split <;> rename_i h₂
-    · rw [Array.getElem_push_lt]
-    · have h₃ : i = acc.size := by omega
-      subst h₃
-      simp
-    · omega
-    · have h₃ : i - acc.size = (i - (acc.size + 1)) + 1 := by omega
-      simp [h₃]
-
-@[simp] theorem getElem_mapFinIdx {as : List α} {f : Fin as.length → α → β} {i : Nat} {h} :
-    (as.mapFinIdx f)[i] = f ⟨i, by simp at h; omega⟩ (as[i]'(by simp at h; omega)) := by
-  simp [mapFinIdx, getElem_mapFinIdx_go]
-
-theorem mapFinIdx_eq_ofFn {as : List α} {f : Fin as.length → α → β} :
-    as.mapFinIdx f = List.ofFn fun i : Fin as.length => f i as[i] := by
-  apply ext_getElem <;> simp
-
-@[simp] theorem getElem?_mapFinIdx {l : List α} {f : Fin l.length → α → β} {i : Nat} :
-    (l.mapFinIdx f)[i]? = l[i]?.pbind fun x m => f ⟨i, by simp [getElem?_eq_some] at m; exact m.1⟩ x := by
-  simp only [getElem?_eq, length_mapFinIdx, getElem_mapFinIdx]
-  split <;> simp
-
-@[simp]
-theorem mapFinIdx_cons {l : List α} {a : α} {f : Fin (l.length + 1) → α → β} :
-    mapFinIdx (a :: l) f = f 0 a :: mapFinIdx l (fun i => f i.succ) := by
-  apply ext_getElem
-  · simp
-  · rintro (_|i) h₁ h₂ <;> simp
-
-theorem mapFinIdx_append {K L : List α} {f : Fin (K ++ L).length → α → β} :
-    (K ++ L).mapFinIdx f =
-      K.mapFinIdx (fun i => f (i.castLE (by simp))) ++ L.mapFinIdx (fun i => f ((i.natAdd K.length).cast (by simp))) := by
-  apply ext_getElem
-  · simp
-  · intro i h₁ h₂
-    rw [getElem_append]
-    simp only [getElem_mapFinIdx, length_mapFinIdx]
-    split <;> rename_i h
-    · rw [getElem_append_left]
-      congr
-    · simp only [Nat.not_lt] at h
-      rw [getElem_append_right h]
-      congr
-      simp
-      omega
-
-@[simp] theorem mapFinIdx_concat {l : List α} {e : α} {f : Fin (l ++ [e]).length → α → β}:
-    (l ++ [e]).mapFinIdx f = l.mapFinIdx (fun i => f (i.castLE (by simp))) ++ [f ⟨l.length, by simp⟩ e] := by
-  simp [mapFinIdx_append]
-  congr
-
-theorem mapFinIdx_singleton {a : α} {f : Fin 1 → α → β} :
-    [a].mapFinIdx f = [f ⟨0, by simp⟩ a] := by
-  simp
-
-theorem mapFinIdx_eq_enum_map {l : List α} {f : Fin l.length → α → β} :
-    l.mapFinIdx f = l.enum.attach.map
-      fun ⟨⟨i, x⟩, m⟩ => f ⟨i, by rw [mk_mem_enum_iff_getElem?, getElem?_eq_some] at m; exact m.1⟩ x := by
-  apply ext_getElem <;> simp
-
-@[simp]
-theorem mapFinIdx_eq_nil_iff {l : List α} {f : Fin l.length → α → β} :
-    l.mapFinIdx f = [] ↔ l = [] := by
-  rw [mapFinIdx_eq_enum_map, map_eq_nil_iff, attach_eq_nil_iff, enum_eq_nil_iff]
-
-theorem mapFinIdx_ne_nil_iff {l : List α} {f : Fin l.length → α → β} :
-    l.mapFinIdx f ≠ [] ↔ l ≠ [] := by
-  simp
-
-theorem exists_of_mem_mapFinIdx {b : β} {l : List α} {f : Fin l.length → α → β}
-    (h : b ∈ l.mapFinIdx f) : ∃ (i : Fin l.length), f i l[i] = b := by
-  rw [mapFinIdx_eq_enum_map] at h
-  replace h := exists_of_mem_map h
-  simp only [mem_attach, true_and, Subtype.exists, Prod.exists, mk_mem_enum_iff_getElem?] at h
-  obtain ⟨i, b, h, rfl⟩ := h
-  rw [getElem?_eq_some_iff] at h
-  obtain ⟨h', rfl⟩ := h
-  exact ⟨⟨i, h'⟩, rfl⟩
-
-@[simp] theorem mem_mapFinIdx {b : β} {l : List α} {f : Fin l.length → α → β} :
-    b ∈ l.mapFinIdx f ↔ ∃ (i : Fin l.length), f i l[i] = b := by
-  constructor
-  · intro h
-    exact exists_of_mem_mapFinIdx h
-  · rintro ⟨i, h, rfl⟩
-    rw [mem_iff_getElem]
-    exact ⟨i, by simp⟩
-
-theorem mapFinIdx_eq_cons_iff {l : List α} {b : β} {f : Fin l.length → α → β} :
-    l.mapFinIdx f = b :: l₂ ↔
-      ∃ (a : α) (l₁ : List α) (h : l = a :: l₁),
-        f ⟨0, by simp [h]⟩ a = b ∧ l₁.mapFinIdx (fun i => f (i.succ.cast (by simp [h]))) = l₂ := by
-  cases l with
-  | nil => simp
-  | cons x l' =>
-    simp only [mapFinIdx_cons, cons.injEq, length_cons, Fin.zero_eta, Fin.cast_succ_eq,
-      exists_and_left]
-    constructor
-    · rintro ⟨rfl, rfl⟩
-      refine ⟨x, rfl, l', by simp⟩
-    · rintro ⟨a, ⟨rfl, h⟩, ⟨_, ⟨rfl, rfl⟩, h⟩⟩
-      exact ⟨rfl, h⟩
-
-theorem mapFinIdx_eq_cons_iff' {l : List α} {b : β} {f : Fin l.length → α → β} :
-    l.mapFinIdx f = b :: l₂ ↔
-      l.head?.pbind (fun x m => (f ⟨0, by cases l <;> simp_all⟩ x)) = some b ∧
-        l.tail?.attach.map (fun ⟨t, m⟩ => t.mapFinIdx fun i => f (i.succ.cast (by cases l <;> simp_all))) = some l₂ := by
-  cases l <;> simp
-
-theorem mapFinIdx_eq_iff {l : List α} {f : Fin l.length → α → β} :
-    l.mapFinIdx f = l' ↔ ∃ h : l'.length = l.length, ∀ (i : Nat) (h : i < l.length), l'[i] = f ⟨i, h⟩ l[i] := by
-  constructor
-  · rintro rfl
-    simp
-  · rintro ⟨h, w⟩
-    apply ext_getElem <;> simp_all
-
-theorem mapFinIdx_eq_mapFinIdx_iff {l : List α} {f g : Fin l.length → α → β} :
-    l.mapFinIdx f = l.mapFinIdx g ↔ ∀ (i : Fin l.length), f i l[i] = g i l[i] := by
-  rw [eq_comm, mapFinIdx_eq_iff]
-  simp [Fin.forall_iff]
-
-@[simp] theorem mapFinIdx_mapFinIdx {l : List α} {f : Fin l.length → α → β} {g : Fin _ → β → γ} :
-    (l.mapFinIdx f).mapFinIdx g = l.mapFinIdx (fun i => g (i.cast (by simp)) ∘ f i) := by
-  simp [mapFinIdx_eq_iff]
-
-theorem mapFinIdx_eq_replicate_iff {l : List α} {f : Fin l.length → α → β} {b : β} :
-    l.mapFinIdx f = replicate l.length b ↔ ∀ (i : Fin l.length), f i l[i] = b := by
-  simp [eq_replicate_iff, length_mapFinIdx, mem_mapFinIdx, forall_exists_index, true_and]
-
-@[simp] theorem mapFinIdx_reverse {l : List α} {f : Fin l.reverse.length → α → β} :
-    l.reverse.mapFinIdx f = (l.mapFinIdx (fun i => f ⟨l.length - 1 - i, by simp; omega⟩)).reverse := by
-  simp [mapFinIdx_eq_iff]
-  intro i h
-  congr
-  omega
-
-/-! ### mapIdx -/
-
 @[simp]
 theorem mapIdx_nil {f : Nat → α → β} : mapIdx f [] = [] :=
   rfl
 
+theorem mapIdx_go_append  {l₁ l₂ : List α} {arr : Array β} :
+    mapIdx.go f (l₁ ++ l₂) arr = mapIdx.go f l₂ (List.toArray (mapIdx.go f l₁ arr)) := by
+  generalize h : (l₁ ++ l₂).length = len
+  induction len generalizing l₁ arr with
+  | zero =>
+    have l₁_nil : l₁ = [] := by
+      cases l₁
+      · rfl
+      · contradiction
+    have l₂_nil : l₂ = [] := by
+      cases l₂
+      · rfl
+      · rw [List.length_append] at h; contradiction
+    rw [l₁_nil, l₂_nil]; simp only [mapIdx.go, List.toArray_toList]
+  | succ len ih =>
+    cases l₁ with
+    | nil =>
+      simp only [mapIdx.go, nil_append, List.toArray_toList]
+    | cons head tail =>
+      simp only [mapIdx.go, List.append_eq]
+      rw [ih]
+      · simp only [cons_append, length_cons, length_append, Nat.succ.injEq] at h
+        simp only [length_append, h]
+
 theorem mapIdx_go_length {arr : Array β} :
     length (mapIdx.go f l arr) = length l + arr.size := by
   induction l generalizing arr with
@@ -219,6 +60,16 @@ theorem mapIdx_go_length {arr : Array β} :
   | cons _ _ ih =>
     simp only [mapIdx.go, ih, Array.size_push, Nat.add_succ, length_cons, Nat.add_comm]
 
+@[simp] theorem mapIdx_concat {l : List α} {e : α} :
+    mapIdx f (l ++ [e]) = mapIdx f l ++ [f l.length e] := by
+  unfold mapIdx
+  rw [mapIdx_go_append]
+  simp only [mapIdx.go, Array.size_toArray, mapIdx_go_length, length_nil, Nat.add_zero,
+    Array.push_toList]
+
+@[simp] theorem mapIdx_singleton {a : α} : mapIdx f [a] = [f 0 a] := by
+  simpa using mapIdx_concat (l := [])
+
 theorem length_mapIdx_go : ∀ {l : List α} {arr : Array β},
     (mapIdx.go f l arr).length = l.length + arr.size
   | [], _ => by simp [mapIdx.go]
@@ -261,15 +112,6 @@ theorem getElem?_mapIdx_go : ∀ {l : List α} {arr : Array β} {i : Nat},
   rw [← getElem?_eq_getElem, getElem?_mapIdx, getElem?_eq_getElem (by simpa using h)]
   simp
 
-@[simp] theorem mapFinIdx_eq_mapIdx {l : List α} {f : Fin l.length → α → β} {g : Nat → α → β}
-    (h : ∀ (i : Fin l.length), f i l[i] = g i l[i]) :
-    l.mapFinIdx f = l.mapIdx g := by
-  simp_all [mapFinIdx_eq_iff]
-
-theorem mapIdx_eq_mapFinIdx {l : List α} {f : Nat → α → β} :
-    l.mapIdx f = l.mapFinIdx (fun i => f i) := by
-  simp [mapFinIdx_eq_mapIdx]
-
 theorem mapIdx_eq_enum_map {l : List α} :
     l.mapIdx f = l.enum.map (Function.uncurry f) := by
   ext1 i
@@ -288,16 +130,9 @@ theorem mapIdx_append {K L : List α} :
   | nil => rfl
   | cons _ _ ih => simp [ih (f := fun i => f (i + 1)), Nat.add_assoc]
 
-@[simp] theorem mapIdx_concat {l : List α} {e : α} :
-    mapIdx f (l ++ [e]) = mapIdx f l ++ [f l.length e] := by
-  simp [mapIdx_append]
-
-theorem mapIdx_singleton {a : α} : mapIdx f [a] = [f 0 a] := by
-  simp
-
 @[simp]
 theorem mapIdx_eq_nil_iff {l : List α} : List.mapIdx f l = [] ↔ l = [] := by
-  rw [List.mapIdx_eq_enum_map, List.map_eq_nil_iff, List.enum_eq_nil_iff]
+  rw [List.mapIdx_eq_enum_map, List.map_eq_nil_iff, List.enum_eq_nil]
 
 theorem mapIdx_ne_nil_iff {l : List α} :
     List.mapIdx f l ≠ [] ↔ l ≠ [] := by
@@ -305,8 +140,13 @@ theorem mapIdx_ne_nil_iff {l : List α} :
 
 theorem exists_of_mem_mapIdx {b : β} {l : List α}
     (h : b ∈ mapIdx f l) : ∃ (i : Nat) (h : i < l.length), f i l[i] = b := by
-  rw [mapIdx_eq_mapFinIdx] at h
-  simpa [Fin.exists_iff] using exists_of_mem_mapFinIdx h
+  rw [mapIdx_eq_enum_map] at h
+  replace h := exists_of_mem_map h
+  simp only [Prod.exists, mk_mem_enum_iff_getElem?, Function.uncurry_apply_pair] at h
+  obtain ⟨i, b, h, rfl⟩ := h
+  rw [getElem?_eq_some_iff] at h
+  obtain ⟨h, rfl⟩ := h
+  exact ⟨i, h, rfl⟩
 
 @[simp] theorem mem_mapIdx {b : β} {l : List α} :
     b ∈ mapIdx f l ↔ ∃ (i : Nat) (h : i < l.length), f i l[i] = b := by

src/Init/Data/List/MinMax.lean

@@ -75,7 +75,7 @@ theorem le_min?_iff [Min α] [LE α]
 
 -- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `min_eq_or`,
 -- and `le_min_iff`.
-theorem min?_eq_some_iff [Min α] [LE α] [anti : Std.Antisymm ((· : α) ≤ ·)]
+theorem min?_eq_some_iff [Min α] [LE α] [anti : Antisymm ((· : α) ≤ ·)]
     (le_refl : ∀ a : α, a ≤ a)
     (min_eq_or : ∀ a b : α, min a b = a ∨ min a b = b)
     (le_min_iff : ∀ a b c : α, a ≤ min b c ↔ a ≤ b ∧ a ≤ c) {xs : List α} :
@@ -146,7 +146,7 @@ theorem max?_le_iff [Max α] [LE α]
 
 -- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `max_eq_or`,
 -- and `le_min_iff`.
-theorem max?_eq_some_iff [Max α] [LE α] [anti : Std.Antisymm ((· : α) ≤ ·)]
+theorem max?_eq_some_iff [Max α] [LE α] [anti : Antisymm ((· : α) ≤ ·)]
     (le_refl : ∀ a : α, a ≤ a)
     (max_eq_or : ∀ a b : α, max a b = a ∨ max a b = b)
     (max_le_iff : ∀ a b c : α, max b c ≤ a ↔ b ≤ a ∧ c ≤ a) {xs : List α} :

src/Init/Data/List/Monadic.lean

@@ -5,7 +5,6 @@ Authors: Parikshit Khanna, Jeremy Avigad, Leonardo de Moura, Floris van Doorn, M
 -/
 prelude
 import Init.Data.List.TakeDrop
-import Init.Data.List.Attach
 
 /-!
 # Lemmas about `List.mapM` and `List.forM`.
@@ -49,9 +48,6 @@ theorem mapM'_eq_mapM [Monad m] [LawfulMonad m] (f : α → m β) (l : List α)
 @[simp] theorem mapM_cons [Monad m] [LawfulMonad m] (f : α → m β) :
     (a :: l).mapM f = (return (← f a) :: (← l.mapM f)) := by simp [← mapM'_eq_mapM, mapM']
 
-@[simp] theorem mapM_id {l : List α} {f : α → Id β} : l.mapM f = l.map f := by
-  induction l <;> simp_all
-
 @[simp] theorem mapM_append [Monad m] [LawfulMonad m] (f : α → m β) {l₁ l₂ : List α} :
     (l₁ ++ l₂).mapM f = (return (← l₁.mapM f) ++ (← l₂.mapM f)) := by induction l₁ <;> simp [*]
 
@@ -76,52 +72,6 @@ theorem mapM_eq_reverse_foldlM_cons [Monad m] [LawfulMonad m] (f : α → m β)
       reverse_cons, reverse_nil, nil_append, singleton_append]
     simp [bind_pure_comp]
 
-/-! ### foldlM and foldrM -/
-
-theorem foldlM_map [Monad m] (f : β₁ → β₂) (g : α → β₂ → m α) (l : List β₁) (init : α) :
-    (l.map f).foldlM g init = l.foldlM (fun x y => g x (f y)) init := by
-  induction l generalizing g init <;> simp [*]
-
-theorem foldrM_map [Monad m] [LawfulMonad m] (f : β₁ → β₂) (g : β₂ → α → m α) (l : List β₁)
-    (init : α) : (l.map f).foldrM g init = l.foldrM (fun x y => g (f x) y) init := by
-  induction l generalizing g init <;> simp [*]
-
-theorem foldlM_filterMap [Monad m] [LawfulMonad m] (f : α → Option β) (g : γ → β → m γ) (l : List α) (init : γ) :
-    (l.filterMap f).foldlM g init =
-      l.foldlM (fun x y => match f y with | some b => g x b | none => pure x) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filterMap_cons, foldlM_cons]
-    cases f a <;> simp [ih]
-
-theorem foldrM_filterMap [Monad m] [LawfulMonad m] (f : α → Option β) (g : β → γ → m γ) (l : List α) (init : γ) :
-    (l.filterMap f).foldrM g init =
-      l.foldrM (fun x y => match f x with | some b => g b y | none => pure y) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filterMap_cons, foldrM_cons]
-    cases f a <;> simp [ih]
-
-theorem foldlM_filter [Monad m] [LawfulMonad m] (p : α → Bool) (g : β → α → m β) (l : List α) (init : β) :
-    (l.filter p).foldlM g init =
-      l.foldlM (fun x y => if p y then g x y else pure x) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filter_cons, foldlM_cons]
-    split <;> simp [ih]
-
-theorem foldrM_filter [Monad m] [LawfulMonad m] (p : α → Bool) (g : α → β → m β) (l : List α) (init : β) :
-    (l.filter p).foldrM g init =
-      l.foldrM (fun x y => if p x then g x y else pure y) init := by
-  induction l generalizing init with
-  | nil => rfl
-  | cons a l ih =>
-    simp only [filter_cons, foldrM_cons]
-    split <;> simp [ih]
-
 /-! ### forM -/
 
 -- We use `List.forM` as the simp normal form, rather that `ForM.forM`.
@@ -137,176 +87,6 @@ theorem foldrM_filter [Monad m] [LawfulMonad m] (p : α → Bool) (g : α → β
     (l₁ ++ l₂).forM f = (do l₁.forM f; l₂.forM f) := by
   induction l₁ <;> simp [*]
 
-/-! ### forIn' -/
-
-theorem forIn'_loop_congr [Monad m] {as bs : List α}
-    {f : (a' : α) → a' ∈ as → β → m (ForInStep β)}
-    {g : (a' : α) → a' ∈ bs → β → m (ForInStep β)}
-    {b : β} (ha : ∃ ys, ys ++ xs = as) (hb : ∃ ys, ys ++ xs = bs)
-    (h : ∀ a m m' b, f a m b = g a m' b) : forIn'.loop as f xs b ha = forIn'.loop bs g xs b hb  := by
-  induction xs generalizing b with
-  | nil => simp [forIn'.loop]
-  | cons a xs ih =>
-    simp only [forIn'.loop] at *
-    congr 1
-    · rw [h]
-    · funext s
-      obtain b | b := s
-      · rfl
-      · simp
-        rw [ih]
-
-@[simp] theorem forIn'_cons [Monad m] {a : α} {as : List α}
-    (f : (a' : α) → a' ∈ a :: as → β → m (ForInStep β)) (b : β) :
-    forIn' (a::as) b f = f a (mem_cons_self a as) b >>=
-      fun | ForInStep.done b => pure b | ForInStep.yield b => forIn' as b fun a' m b => f a' (mem_cons_of_mem a m) b := by
-  simp only [forIn', List.forIn', forIn'.loop]
-  congr 1
-  funext s
-  obtain b | b := s
-  · rfl
-  · apply forIn'_loop_congr
-    intros
-    rfl
-
-@[simp] theorem forIn_cons [Monad m] (f : α → β → m (ForInStep β)) (a : α) (as : List α) (b : β) :
-    forIn (a::as) b f = f a b >>= fun | ForInStep.done b => pure b | ForInStep.yield b => forIn as b f := by
-  have := forIn'_cons (a := a) (as := as) (fun a' _ b => f a' b) b
-  simpa only [forIn'_eq_forIn]
-
-@[congr] theorem forIn'_congr [Monad m] {as bs : List α} (w : as = bs)
-    {b b' : β} (hb : b = b')
-    {f : (a' : α) → a' ∈ as → β → m (ForInStep β)}
-    {g : (a' : α) → a' ∈ bs → β → m (ForInStep β)}
-    (h : ∀ a m b, f a (by simpa [w] using m) b = g a m b) :
-    forIn' as b f = forIn' bs b' g := by
-  induction bs generalizing as b b' with
-  | nil =>
-    subst w
-    simp [hb, forIn'_nil]
-  | cons b bs ih =>
-    cases as with
-    | nil => simp at w
-    | cons a as =>
-      simp only [cons.injEq] at w
-      obtain ⟨rfl, rfl⟩ := w
-      simp only [forIn'_cons]
-      congr 1
-      · simp [h, hb]
-      · funext s
-        obtain b | b := s
-        · rfl
-        · simp
-          rw [ih rfl rfl]
-          intro a m b
-          exact h a (mem_cons_of_mem _ m) b
-
-/--
-We can express a for loop over a list as a fold,
-in which whenever we reach `.done b` we keep that value through the rest of the fold.
--/
-theorem forIn'_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : List α) (f : (a : α) → a ∈ l → β → m (ForInStep β)) (init : β) :
-    forIn' l init f = ForInStep.value <$>
-      l.attach.foldlM (fun b ⟨a, m⟩ => match b with
-        | .yield b => f a m b
-        | .done b => pure (.done b)) (ForInStep.yield init) := by
-  induction l generalizing init with
-  | nil => simp
-  | cons a as ih =>
-    simp only [forIn'_cons, attach_cons, foldlM_cons, _root_.map_bind]
-    congr 1
-    funext x
-    match x with
-    | .done b =>
-      clear ih
-      dsimp
-      induction as with
-      | nil => simp
-      | cons a as ih =>
-        simp only [attach_cons, map_cons, map_map, Function.comp_def, foldlM_cons, pure_bind]
-        specialize ih (fun a m b => f a (by
-          simp only [mem_cons] at m
-          rcases m with rfl|m
-          · apply mem_cons_self
-          · exact mem_cons_of_mem _ (mem_cons_of_mem _ m)) b)
-        simp [ih, List.foldlM_map]
-    | .yield b =>
-      simp [ih, List.foldlM_map]
-
-/-- We can express a for loop over a list which always yields as a fold. -/
-@[simp] theorem forIn'_yield_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : List α) (f : (a : α) → a ∈ l → β → m γ) (g : (a : α) → a ∈ l → β → γ → β) (init : β) :
-    forIn' l init (fun a m b => (fun c => .yield (g a m b c)) <$> f a m b) =
-      l.attach.foldlM (fun b ⟨a, m⟩ => g a m b <$> f a m b) init := by
-  simp only [forIn'_eq_foldlM]
-  generalize l.attach = l'
-  induction l' generalizing init <;> simp_all
-
-theorem forIn'_pure_yield_eq_foldl [Monad m] [LawfulMonad m]
-    (l : List α) (f : (a : α) → a ∈ l → β → β) (init : β) :
-    forIn' l init (fun a m b => pure (.yield (f a m b))) =
-      pure (f := m) (l.attach.foldl (fun b ⟨a, h⟩ => f a h b) init) := by
-  simp only [forIn'_eq_foldlM]
-  generalize l.attach = l'
-  induction l' generalizing init <;> simp_all
-
-@[simp] theorem forIn'_yield_eq_foldl
-    (l : List α) (f : (a : α) → a ∈ l → β → β) (init : β) :
-    forIn' (m := Id) l init (fun a m b => .yield (f a m b)) =
-      l.attach.foldl (fun b ⟨a, h⟩ => f a h b) init := by
-  simp only [forIn'_eq_foldlM]
-  generalize l.attach = l'
-  induction l' generalizing init <;> simp_all
-
-/--
-We can express a for loop over a list as a fold,
-in which whenever we reach `.done b` we keep that value through the rest of the fold.
--/
-theorem forIn_eq_foldlM [Monad m] [LawfulMonad m]
-    (f : α → β → m (ForInStep β)) (init : β) (l : List α) :
-    forIn l init f = ForInStep.value <$>
-      l.foldlM (fun b a => match b with
-        | .yield b => f a b
-        | .done b => pure (.done b)) (ForInStep.yield init) := by
-  induction l generalizing init with
-  | nil => simp
-  | cons a as ih =>
-    simp only [foldlM_cons, bind_pure_comp, forIn_cons, _root_.map_bind]
-    congr 1
-    funext x
-    match x with
-    | .done b =>
-      clear ih
-      dsimp
-      induction as with
-      | nil => simp
-      | cons a as ih => simp [ih]
-    | .yield b =>
-      simp [ih]
-
-/-- We can express a for loop over a list which always yields as a fold. -/
-@[simp] theorem forIn_yield_eq_foldlM [Monad m] [LawfulMonad m]
-    (l : List α) (f : α → β → m γ) (g : α → β → γ → β) (init : β) :
-    forIn l init (fun a b => (fun c => .yield (g a b c)) <$> f a b) =
-      l.foldlM (fun b a => g a b <$> f a b) init := by
-  simp only [forIn_eq_foldlM]
-  induction l generalizing init <;> simp_all
-
-theorem forIn_pure_yield_eq_foldl [Monad m] [LawfulMonad m]
-    (l : List α) (f : α → β → β) (init : β) :
-    forIn l init (fun a b => pure (.yield (f a b))) =
-      pure (f := m) (l.foldl (fun b a => f a b) init) := by
-  simp only [forIn_eq_foldlM]
-  induction l generalizing init <;> simp_all
-
-@[simp] theorem forIn_yield_eq_foldl
-    (l : List α) (f : α → β → β) (init : β) :
-    forIn (m := Id) l init (fun a b => .yield (f a b)) =
-      l.foldl (fun b a => f a b) init := by
-  simp only [forIn_eq_foldlM]
-  induction l generalizing init <;> simp_all
-
 /-! ### allM -/
 
 theorem allM_eq_not_anyM_not [Monad m] [LawfulMonad m] (p : α → m Bool) (as : List α) :

src/Init/Data/List/Nat.lean

@@ -12,6 +12,3 @@ import Init.Data.List.Nat.TakeDrop
 import Init.Data.List.Nat.Count
 import Init.Data.List.Nat.Erase
 import Init.Data.List.Nat.Find
-import Init.Data.List.Nat.BEq
-import Init.Data.List.Nat.Modify
-import Init.Data.List.Nat.InsertIdx

src/Init/Data/List/Nat/BEq.lean

@@ -1,47 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Kim Morrison
--/
-prelude
-import Init.Data.Nat.Lemmas
-import Init.Data.List.Basic
-
-namespace List
-
-/-! ### isEqv-/
-
-theorem isEqv_eq_decide (a b : List α) (r) :
-    isEqv a b r = if h : a.length = b.length then
-      decide (∀ (i : Nat) (h' : i < a.length), r (a[i]'(h ▸ h')) (b[i]'(h ▸ h'))) else false := by
-  induction a generalizing b with
-  | nil =>
-    cases b <;> simp
-  | cons a as ih =>
-    cases b with
-    | nil => simp
-    | cons b bs =>
-      simp only [isEqv, ih, length_cons, Nat.add_right_cancel_iff]
-      split <;> simp [Nat.forall_lt_succ_left']
-
-/-! ### beq -/
-
-theorem beq_eq_isEqv [BEq α] (a b : List α) : a.beq b = isEqv a b (· == ·) := by
-  induction a generalizing b with
-  | nil =>
-    cases b <;> simp
-  | cons a as ih =>
-    cases b with
-    | nil => simp
-    | cons b bs =>
-      simp only [beq_cons₂, ih, isEqv_eq_decide, length_cons, Nat.add_right_cancel_iff,
-        Nat.forall_lt_succ_left', getElem_cons_zero, getElem_cons_succ, Bool.decide_and,
-        Bool.decide_eq_true]
-      split <;> simp
-
-theorem beq_eq_decide [BEq α] (a b : List α) :
-    (a == b) = if h : a.length = b.length then
-      decide (∀ (i : Nat) (h' : i < a.length), a[i] == b[i]'(h ▸ h')) else false := by
-  simp [BEq.beq, beq_eq_isEqv, isEqv_eq_decide]
-
-end List

src/Init/Data/List/Nat/Erase.lean

@@ -64,82 +64,3 @@ theorem getElem_eraseIdx_of_ge (l : List α) (i : Nat) (j : Nat) (h : j < (l.era
     (l.eraseIdx i)[j] = l[j + 1]'(by rw [length_eraseIdx] at h; split at h <;> omega) := by
   rw [getElem_eraseIdx, dif_neg]
   omega
-
-theorem eraseIdx_set_eq {l : List α} {i : Nat} {a : α} :
-    (l.set i a).eraseIdx i = l.eraseIdx i := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro n h₁ h₂
-    rw [getElem_eraseIdx, getElem_eraseIdx]
-    split <;>
-    · rw [getElem_set_ne]
-      omega
-
-theorem eraseIdx_set_lt {l : List α} {i : Nat} {j : Nat} {a : α} (h : j < i) :
-    (l.set i a).eraseIdx j = (l.eraseIdx j).set (i - 1) a := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro n h₁ h₂
-    simp only [length_eraseIdx, length_set] at h₁
-    simp only [getElem_eraseIdx, getElem_set]
-    split
-    · split
-      · split
-        · rfl
-        · omega
-      · split
-        · omega
-        · rfl
-    · split
-      · split
-        · rfl
-        · omega
-      · have t : i - 1 ≠ n := by omega
-        simp [t]
-
-theorem eraseIdx_set_gt {l : List α} {i : Nat} {j : Nat} {a : α} (h : i < j) :
-    (l.set i a).eraseIdx j = (l.eraseIdx j).set i a := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro n h₁ h₂
-    simp only [length_eraseIdx, length_set] at h₁
-    simp only [getElem_eraseIdx, getElem_set]
-    split
-    · rfl
-    · split
-      · split
-        · rfl
-        · omega
-      · have t : i ≠ n := by omega
-        simp [t]
-
-@[simp] theorem set_getElem_succ_eraseIdx_succ
-    {l : List α} {i : Nat} (h : i + 1 < l.length) :
-    (l.eraseIdx (i + 1)).set i l[i + 1] = l.eraseIdx i := by
-  apply ext_getElem
-  · simp only [length_set, length_eraseIdx, h, ↓reduceIte]
-    rw [if_pos]
-    omega
-  · intro n h₁ h₂
-    simp [getElem_set, getElem_eraseIdx]
-    split
-    · split
-      · omega
-      · simp_all
-    · split
-      · split
-        · rfl
-        · omega
-      · have t : ¬ n < i := by omega
-        simp [t]
-
-@[simp] theorem eraseIdx_length_sub_one (l : List α) :
-    (l.eraseIdx (l.length - 1)) = l.dropLast := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-    omega
-  · intro n h₁ h₂
-    rw [getElem_eraseIdx_of_lt, getElem_dropLast]
-    simp_all
-
-end List

src/Init/Data/List/Nat/Find.lean

@@ -9,32 +9,6 @@ import Init.Data.List.Find
 
 namespace List
 
-open Nat
-
-theorem find?_eq_some_iff_getElem {xs : List α} {p : α → Bool} {b : α} :
-    xs.find? p = some b ↔ p b ∧ ∃ i h, xs[i] = b ∧ ∀ j : Nat, (hj : j < i) → !p xs[j] := by
-  rw [find?_eq_some_iff_append]
-  simp only [Bool.not_eq_eq_eq_not, Bool.not_true, exists_and_right, and_congr_right_iff]
-  intro w
-  constructor
-  · rintro ⟨as, ⟨bs, rfl⟩, h⟩
-    refine ⟨as.length, ⟨?_, ?_, ?_⟩⟩
-    · simp only [length_append, length_cons]
-      refine Nat.lt_add_of_pos_right (zero_lt_succ bs.length)
-    · rw [getElem_append_right (Nat.le_refl as.length)]
-      simp
-    · intro j h'
-      rw [getElem_append_left h']
-      exact h _ (getElem_mem h')
-  · rintro ⟨i, h, rfl, h'⟩
-    refine ⟨xs.take i, ⟨xs.drop (i+1), ?_⟩, ?_⟩
-    · rw [getElem_cons_drop, take_append_drop]
-    · intro a m
-      rw [mem_take_iff_getElem] at m
-      obtain ⟨j, h, rfl⟩ := m
-      apply h'
-      omega
-
 theorem findIdx?_eq_some_le_of_findIdx?_eq_some {xs : List α} {p q : α → Bool} (w : ∀ x ∈ xs, p x → q x) {i : Nat}
     (h : xs.findIdx? p = some i) : ∃ j, j ≤ i ∧ xs.findIdx? q = some j := by
   simp only [findIdx?_eq_findSome?_enum] at h

src/Init/Data/List/Nat/InsertIdx.lean

@@ -1,242 +0,0 @@
-/-
-Copyright (c) 2014 Parikshit Khanna. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Parikshit Khanna, Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Mario Carneiro
--/
-prelude
-import Init.Data.List.Nat.Modify
-
-/-!
-# insertIdx
-
-Proves various lemmas about `List.insertIdx`.
--/
-
-open Function
-
-open Nat
-
-namespace List
-
-universe u
-
-variable {α : Type u}
-
-section InsertIdx
-
-variable {a : α}
-
-@[simp]
-theorem insertIdx_zero (s : List α) (x : α) : insertIdx 0 x s = x :: s :=
-  rfl
-
-@[simp]
-theorem insertIdx_succ_nil (n : Nat) (a : α) : insertIdx (n + 1) a [] = [] :=
-  rfl
-
-@[simp]
-theorem insertIdx_succ_cons (s : List α) (hd x : α) (n : Nat) :
-    insertIdx (n + 1) x (hd :: s) = hd :: insertIdx n x s :=
-  rfl
-
-theorem length_insertIdx : ∀ n as, (insertIdx n a as).length = if n ≤ as.length then as.length + 1 else as.length
-  | 0, _ => by simp
-  | n + 1, [] => by simp
-  | n + 1, a :: as => by
-    simp only [insertIdx_succ_cons, length_cons, length_insertIdx, Nat.add_le_add_iff_right]
-    split <;> rfl
-
-theorem length_insertIdx_of_le_length (h : n ≤ length as) : length (insertIdx n a as) = length as + 1 := by
-  simp [length_insertIdx, h]
-
-theorem length_insertIdx_of_length_lt (h : length as < n) : length (insertIdx n a as) = length as := by
-  simp [length_insertIdx, h]
-
-theorem eraseIdx_insertIdx (n : Nat) (l : List α) : (l.insertIdx n a).eraseIdx n = l := by
-  rw [eraseIdx_eq_modifyTailIdx, insertIdx, modifyTailIdx_modifyTailIdx_self]
-  exact modifyTailIdx_id _ _
-
-theorem insertIdx_eraseIdx_of_ge :
-    ∀ n m as,
-      n < length as → n ≤ m → insertIdx m a (as.eraseIdx n) = (as.insertIdx (m + 1) a).eraseIdx n
-  | 0, 0, [], has, _ => (Nat.lt_irrefl _ has).elim
-  | 0, 0, _ :: as, _, _ => by simp [eraseIdx, insertIdx]
-  | 0, _ + 1, _ :: _, _, _ => rfl
-  | n + 1, m + 1, a :: as, has, hmn =>
-    congrArg (cons a) <|
-      insertIdx_eraseIdx_of_ge n m as (Nat.lt_of_succ_lt_succ has) (Nat.le_of_succ_le_succ hmn)
-
-theorem insertIdx_eraseIdx_of_le :
-    ∀ n m as,
-      n < length as → m ≤ n → insertIdx m a (as.eraseIdx n) = (as.insertIdx m a).eraseIdx (n + 1)
-  | _, 0, _ :: _, _, _ => rfl
-  | n + 1, m + 1, a :: as, has, hmn =>
-    congrArg (cons a) <|
-      insertIdx_eraseIdx_of_le n m as (Nat.lt_of_succ_lt_succ has) (Nat.le_of_succ_le_succ hmn)
-
-theorem insertIdx_comm (a b : α) :
-    ∀ (i j : Nat) (l : List α) (_ : i ≤ j) (_ : j ≤ length l),
-      (l.insertIdx i a).insertIdx (j + 1) b = (l.insertIdx j b).insertIdx i a
-  | 0, j, l => by simp [insertIdx]
-  | _ + 1, 0, _ => fun h => (Nat.not_lt_zero _ h).elim
-  | i + 1, j + 1, [] => by simp
-  | i + 1, j + 1, c :: l => fun h₀ h₁ => by
-    simp only [insertIdx_succ_cons, cons.injEq, true_and]
-    exact insertIdx_comm a b i j l (Nat.le_of_succ_le_succ h₀) (Nat.le_of_succ_le_succ h₁)
-
-theorem mem_insertIdx {a b : α} :
-    ∀ {n : Nat} {l : List α} (_ : n ≤ l.length), a ∈ l.insertIdx n b ↔ a = b ∨ a ∈ l
-  | 0, as, _ => by simp
-  | _ + 1, [], h => (Nat.not_succ_le_zero _ h).elim
-  | n + 1, a' :: as, h => by
-    rw [List.insertIdx_succ_cons, mem_cons, mem_insertIdx (Nat.le_of_succ_le_succ h),
-      ← or_assoc, @or_comm (a = a'), or_assoc, mem_cons]
-
-theorem insertIdx_of_length_lt (l : List α) (x : α) (n : Nat) (h : l.length < n) :
-    insertIdx n x l = l := by
-  induction l generalizing n with
-  | nil =>
-    cases n
-    · simp at h
-    · simp
-  | cons x l ih =>
-    cases n
-    · simp at h
-    · simp only [Nat.succ_lt_succ_iff, length] at h
-      simpa using ih _ h
-
-@[simp]
-theorem insertIdx_length_self (l : List α) (x : α) : insertIdx l.length x l = l ++ [x] := by
-  induction l with
-  | nil => simp
-  | cons x l ih => simpa using ih
-
-theorem length_le_length_insertIdx (l : List α) (x : α) (n : Nat) :
-    l.length ≤ (insertIdx n x l).length := by
-  simp only [length_insertIdx]
-  split <;> simp
-
-theorem length_insertIdx_le_succ (l : List α) (x : α) (n : Nat) :
-    (insertIdx n x l).length ≤ l.length + 1 := by
-  simp only [length_insertIdx]
-  split <;> simp
-
-theorem getElem_insertIdx_of_lt {l : List α} {x : α} {n k : Nat} (hn : k < n)
-    (hk : k < (insertIdx n x l).length) :
-    (insertIdx n x l)[k] = l[k]'(by simp [length_insertIdx] at hk; split at hk <;> omega) := by
-  induction n generalizing k l with
-  | zero => simp at hn
-  | succ n ih =>
-    cases l with
-    | nil => simp
-    | cons _ _=>
-      cases k
-      · simp [get]
-      · rw [Nat.succ_lt_succ_iff] at hn
-        simpa using ih hn _
-
-@[simp]
-theorem getElem_insertIdx_self {l : List α} {x : α} {n : Nat} (hn : n < (insertIdx n x l).length) :
-    (insertIdx n x l)[n] = x := by
-  induction l generalizing n with
-  | nil =>
-    simp [length_insertIdx] at hn
-    split at hn
-    · simp_all
-    · omega
-  | cons _ _ ih =>
-    cases n
-    · simp
-    · simp only [insertIdx_succ_cons, length_cons, length_insertIdx, Nat.add_lt_add_iff_right] at hn ih
-      simpa using ih hn
-
-theorem getElem_insertIdx_of_ge {l : List α} {x : α} {n k : Nat} (hn : n + 1 ≤ k)
-    (hk : k < (insertIdx n x l).length) :
-    (insertIdx n x l)[k] = l[k - 1]'(by simp [length_insertIdx] at hk; split at hk <;> omega) := by
-  induction l generalizing n k with
-  | nil =>
-    cases n with
-    | zero =>
-      simp only [insertIdx_zero, length_singleton, lt_one_iff] at hk
-      omega
-    | succ n => simp at hk
-  | cons _ _ ih =>
-    cases n with
-    | zero =>
-      simp only [insertIdx_zero] at hk
-      cases k with
-      | zero => omega
-      | succ k => simp
-    | succ n =>
-      cases k with
-      | zero => simp
-      | succ k =>
-        simp only [insertIdx_succ_cons, getElem_cons_succ]
-        rw [ih (by omega)]
-        cases k with
-        | zero => omega
-        | succ k => simp
-
-theorem getElem_insertIdx {l : List α} {x : α} {n k : Nat} (h : k < (insertIdx n x l).length) :
-    (insertIdx n x l)[k] =
-      if h₁ : k < n then
-        l[k]'(by simp [length_insertIdx] at h; split at h <;> omega)
-      else
-        if h₂ : k = n then
-          x
-        else
-          l[k-1]'(by simp [length_insertIdx] at h; split at h <;> omega) := by
-  split <;> rename_i h₁
-  · rw [getElem_insertIdx_of_lt h₁]
-  · split <;> rename_i h₂
-    · subst h₂
-      rw [getElem_insertIdx_self h]
-    · rw [getElem_insertIdx_of_ge (by omega)]
-
-theorem getElem?_insertIdx {l : List α} {x : α} {n k : Nat} :
-    (insertIdx n x l)[k]? =
-      if k < n then
-        l[k]?
-      else
-        if k = n then
-          if k ≤ l.length then some x else none
-        else
-          l[k-1]? := by
-  rw [getElem?_def]
-  split <;> rename_i h
-  · rw [getElem_insertIdx h]
-    simp only [length_insertIdx] at h
-    split <;> rename_i h₁
-    · rw [getElem?_def, dif_pos]
-    · split <;> rename_i h₂
-      · rw [if_pos]
-        split at h <;> omega
-      · rw [getElem?_def]
-        simp only [Option.some_eq_dite_none_right, exists_prop, and_true]
-        split at h <;> omega
-  · simp only [length_insertIdx] at h
-    split <;> rename_i h₁
-    · rw [getElem?_eq_none]
-      split at h <;> omega
-    · split <;> rename_i h₂
-      · rw [if_neg]
-        split at h <;> omega
-      · rw [getElem?_eq_none]
-        split at h <;> omega
-
-theorem getElem?_insertIdx_of_lt {l : List α} {x : α} {n k : Nat} (h : k < n) :
-    (insertIdx n x l)[k]? = l[k]? := by
-  rw [getElem?_insertIdx, if_pos h]
-
-theorem getElem?_insertIdx_self {l : List α} {x : α} {n : Nat} :
-    (insertIdx n x l)[n]? = if n ≤ l.length then some x else none := by
-  rw [getElem?_insertIdx, if_neg (by omega)]
-  simp
-
-theorem getElem?_insertIdx_of_ge {l : List α} {x : α} {n k : Nat} (h : n + 1 ≤ k) :
-    (insertIdx n x l)[k]? = l[k - 1]? := by
-  rw [getElem?_insertIdx, if_neg (by omega), if_neg (by omega)]
-
-end InsertIdx
-
-end List

src/Init/Data/List/Nat/Modify.lean

@@ -1,314 +0,0 @@
-/-
-Copyright (c) 2014 Parikshit Khanna. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Parikshit Khanna, Jeremy Avigad, Leonardo de Moura, Floris van Doorn, Mario Carneiro
--/
-
-prelude
-import Init.Data.List.Nat.TakeDrop
-import Init.Data.List.Nat.Erase
-
-namespace List
-
-/-! ### modifyHead -/
-
-@[simp] theorem length_modifyHead {f : α → α} {l : List α} : (l.modifyHead f).length = l.length := by
-  cases l <;> simp [modifyHead]
-
-theorem modifyHead_eq_set [Inhabited α] (f : α → α) (l : List α) :
-    l.modifyHead f = l.set 0 (f (l[0]?.getD default)) := by cases l <;> simp [modifyHead]
-
-@[simp] theorem modifyHead_eq_nil_iff {f : α → α} {l : List α} :
-    l.modifyHead f = [] ↔ l = [] := by cases l <;> simp [modifyHead]
-
-@[simp] theorem modifyHead_modifyHead {l : List α} {f g : α → α} :
-    (l.modifyHead f).modifyHead g = l.modifyHead (g ∘ f) := by cases l <;> simp [modifyHead]
-
-theorem getElem_modifyHead {l : List α} {f : α → α} {n} (h : n < (l.modifyHead f).length) :
-    (l.modifyHead f)[n] = if h' : n = 0 then f (l[0]'(by simp at h; omega)) else l[n]'(by simpa using h) := by
-  cases l with
-  | nil => simp at h
-  | cons hd tl => cases n <;> simp
-
-@[simp] theorem getElem_modifyHead_zero {l : List α} {f : α → α} {h} :
-    (l.modifyHead f)[0] = f (l[0]'(by simpa using h)) := by simp [getElem_modifyHead]
-
-@[simp] theorem getElem_modifyHead_succ {l : List α} {f : α → α} {n} (h : n + 1 < (l.modifyHead f).length) :
-    (l.modifyHead f)[n + 1] = l[n + 1]'(by simpa using h) := by simp [getElem_modifyHead]
-
-theorem getElem?_modifyHead {l : List α} {f : α → α} {n} :
-    (l.modifyHead f)[n]? = if n = 0 then l[n]?.map f else l[n]? := by
-  cases l with
-  | nil => simp
-  | cons hd tl => cases n <;> simp
-
-@[simp] theorem getElem?_modifyHead_zero {l : List α} {f : α → α} :
-    (l.modifyHead f)[0]? = l[0]?.map f := by simp [getElem?_modifyHead]
-
-@[simp] theorem getElem?_modifyHead_succ {l : List α} {f : α → α} {n} :
-    (l.modifyHead f)[n + 1]? = l[n + 1]? := by simp [getElem?_modifyHead]
-
-@[simp] theorem head_modifyHead (f : α → α) (l : List α) (h) :
-    (l.modifyHead f).head h = f (l.head (by simpa using h)) := by
-  cases l with
-  | nil => simp at h
-  | cons hd tl => simp
-
-@[simp] theorem head?_modifyHead {l : List α} {f : α → α} :
-    (l.modifyHead f).head? = l.head?.map f := by cases l <;> simp
-
-@[simp] theorem tail_modifyHead {f : α → α} {l : List α} :
-    (l.modifyHead f).tail = l.tail := by cases l <;> simp
-
-@[simp] theorem take_modifyHead {f : α → α} {l : List α} {n} :
-    (l.modifyHead f).take n = (l.take n).modifyHead f := by
-  cases l <;> cases n <;> simp
-
-@[simp] theorem drop_modifyHead_of_pos {f : α → α} {l : List α} {n} (h : 0 < n) :
-    (l.modifyHead f).drop n = l.drop n := by
-  cases l <;> cases n <;> simp_all
-
-@[simp] theorem eraseIdx_modifyHead_zero {f : α → α} {l : List α} :
-    (l.modifyHead f).eraseIdx 0 = l.eraseIdx 0 := by cases l <;> simp
-
-@[simp] theorem eraseIdx_modifyHead_of_pos {f : α → α} {l : List α} {n} (h : 0 < n) :
-    (l.modifyHead f).eraseIdx n = (l.eraseIdx n).modifyHead f := by cases l <;> cases n <;> simp_all
-
-@[simp] theorem modifyHead_id : modifyHead (id : α → α) = id := by funext l; cases l <;> simp
-
-/-! ### modifyTailIdx -/
-
-@[simp] theorem modifyTailIdx_id : ∀ n (l : List α), l.modifyTailIdx id n = l
-  | 0, _ => rfl
-  | _+1, [] => rfl
-  | n+1, a :: l => congrArg (cons a) (modifyTailIdx_id n l)
-
-theorem eraseIdx_eq_modifyTailIdx : ∀ n (l : List α), eraseIdx l n = modifyTailIdx tail n l
-  | 0, l => by cases l <;> rfl
-  | _+1, [] => rfl
-  | _+1, _ :: _ => congrArg (cons _) (eraseIdx_eq_modifyTailIdx _ _)
-
-@[simp] theorem length_modifyTailIdx (f : List α → List α) (H : ∀ l, length (f l) = length l) :
-    ∀ n l, length (modifyTailIdx f n l) = length l
-  | 0, _ => H _
-  | _+1, [] => rfl
-  | _+1, _ :: _ => congrArg (·+1) (length_modifyTailIdx _ H _ _)
-
-theorem modifyTailIdx_add (f : List α → List α) (n) (l₁ l₂ : List α) :
-    modifyTailIdx f (l₁.length + n) (l₁ ++ l₂) = l₁ ++ modifyTailIdx f n l₂ := by
-  induction l₁ <;> simp [*, Nat.succ_add]
-
-theorem modifyTailIdx_eq_take_drop (f : List α → List α) (H : f [] = []) :
-    ∀ n l, modifyTailIdx f n l = take n l ++ f (drop n l)
-  | 0, _ => rfl
-  | _ + 1, [] => H.symm
-  | n + 1, b :: l => congrArg (cons b) (modifyTailIdx_eq_take_drop f H n l)
-
-theorem exists_of_modifyTailIdx (f : List α → List α) {n} {l : List α} (h : n ≤ l.length) :
-    ∃ l₁ l₂, l = l₁ ++ l₂ ∧ l₁.length = n ∧ modifyTailIdx f n l = l₁ ++ f l₂ :=
-  have ⟨_, _, eq, hl⟩ : ∃ l₁ l₂, l = l₁ ++ l₂ ∧ l₁.length = n :=
-    ⟨_, _, (take_append_drop n l).symm, length_take_of_le h⟩
-  ⟨_, _, eq, hl, hl ▸ eq ▸ modifyTailIdx_add (n := 0) ..⟩
-
-theorem modifyTailIdx_modifyTailIdx {f g : List α → List α} (m : Nat) :
-    ∀ (n) (l : List α),
-      (l.modifyTailIdx f n).modifyTailIdx g (m + n) =
-        l.modifyTailIdx (fun l => (f l).modifyTailIdx g m) n
-  | 0, _ => rfl
-  | _ + 1, [] => rfl
-  | n + 1, a :: l => congrArg (List.cons a) (modifyTailIdx_modifyTailIdx m n l)
-
-theorem modifyTailIdx_modifyTailIdx_le {f g : List α → List α} (m n : Nat) (l : List α)
-    (h : n ≤ m) :
-    (l.modifyTailIdx f n).modifyTailIdx g m =
-      l.modifyTailIdx (fun l => (f l).modifyTailIdx g (m - n)) n := by
-  rcases Nat.exists_eq_add_of_le h with ⟨m, rfl⟩
-  rw [Nat.add_comm, modifyTailIdx_modifyTailIdx, Nat.add_sub_cancel]
-
-theorem modifyTailIdx_modifyTailIdx_self {f g : List α → List α} (n : Nat) (l : List α) :
-    (l.modifyTailIdx f n).modifyTailIdx g n = l.modifyTailIdx (g ∘ f) n := by
-  rw [modifyTailIdx_modifyTailIdx_le n n l (Nat.le_refl n), Nat.sub_self]; rfl
-
-/-! ### modify -/
-
-@[simp] theorem modify_nil (f : α → α) (n) : [].modify f n = [] := by cases n <;> rfl
-
-@[simp] theorem modify_zero_cons (f : α → α) (a : α) (l : List α) :
-    (a :: l).modify f 0 = f a :: l := rfl
-
-@[simp] theorem modify_succ_cons (f : α → α) (a : α) (l : List α) (n) :
-    (a :: l).modify f (n + 1) = a :: l.modify f n := by rfl
-
-theorem modifyHead_eq_modify_zero (f : α → α) (l : List α) :
-    l.modifyHead f = l.modify f 0 := by cases l <;> simp
-
-@[simp] theorem modify_eq_nil_iff (f : α → α) (n) (l : List α) :
-    l.modify f n = [] ↔ l = [] := by cases l <;> cases n <;> simp
-
-theorem getElem?_modify (f : α → α) :
-    ∀ n (l : List α) m, (modify f n l)[m]? = (fun a => if n = m then f a else a) <$> l[m]?
-  | n, l, 0 => by cases l <;> cases n <;> simp
-  | n, [], _+1 => by cases n <;> rfl
-  | 0, _ :: l, m+1 => by cases h : l[m]? <;> simp [h, modify, m.succ_ne_zero.symm]
-  | n+1, a :: l, m+1 => by
-    simp only [modify_succ_cons, getElem?_cons_succ, Nat.reduceEqDiff, Option.map_eq_map]
-    refine (getElem?_modify f n l m).trans ?_
-    cases h' : l[m]? <;> by_cases h : n = m <;>
-      simp [h, if_pos, if_neg, Option.map, mt Nat.succ.inj, not_false_iff, h']
-
-@[simp] theorem length_modify (f : α → α) : ∀ n l, length (modify f n l) = length l :=
-  length_modifyTailIdx _ fun l => by cases l <;> rfl
-
-@[simp] theorem getElem?_modify_eq (f : α → α) (n) (l : List α) :
-    (modify f n l)[n]? = f <$> l[n]? := by
-  simp only [getElem?_modify, if_pos]
-
-@[simp] theorem getElem?_modify_ne (f : α → α) {m n} (l : List α) (h : m ≠ n) :
-    (modify f m l)[n]? = l[n]? := by
-  simp only [getElem?_modify, if_neg h, id_map']
-
-theorem getElem_modify (f : α → α) (n) (l : List α) (m) (h : m < (modify f n l).length) :
-    (modify f n l)[m] =
-      if n = m then f (l[m]'(by simp at h; omega)) else l[m]'(by simp at h; omega) := by
-  rw [getElem_eq_iff, getElem?_modify]
-  simp at h
-  simp [h]
-
-@[simp] theorem getElem_modify_eq (f : α → α) (n) (l : List α) (h) :
-    (modify f n l)[n] = f (l[n]'(by simpa using h)) := by simp [getElem_modify]
-
-@[simp] theorem getElem_modify_ne (f : α → α) {m n} (l : List α) (h : m ≠ n) (h') :
-    (modify f m l)[n] = l[n]'(by simpa using h') := by simp [getElem_modify, h]
-
-theorem modify_eq_self {f : α → α} {n} {l : List α} (h : l.length ≤ n) :
-    l.modify f n = l := by
-  apply ext_getElem
-  · simp
-  · intro m h₁ h₂
-    simp only [getElem_modify, ite_eq_right_iff]
-    intro h
-    omega
-
-theorem modify_modify_eq (f g : α → α) (n) (l : List α) :
-    (modify f n l).modify g n = modify (g ∘ f) n l := by
-  apply ext_getElem
-  · simp
-  · intro m h₁ h₂
-    simp only [getElem_modify, Function.comp_apply]
-    split <;> simp
-
-theorem modify_modify_ne (f g : α → α) {m n} (l : List α) (h : m ≠ n) :
-    (modify f m l).modify g n = (l.modify g n).modify f m := by
-  apply ext_getElem
-  · simp
-  · intro m' h₁ h₂
-    simp only [getElem_modify, getElem_modify_ne, h₂]
-    split <;> split <;> first | rfl | omega
-
-theorem modify_eq_set [Inhabited α] (f : α → α) (n) (l : List α) :
-    modify f n l = l.set n (f (l[n]?.getD default)) := by
-  apply ext_getElem
-  · simp
-  · intro m h₁ h₂
-    simp [getElem_modify, getElem_set, h₂]
-    split <;> rename_i h
-    · subst h
-      simp only [length_modify] at h₁
-      simp [h₁]
-    · rfl
-
-theorem modify_eq_take_drop (f : α → α) :
-    ∀ n l, modify f n l = take n l ++ modifyHead f (drop n l) :=
-  modifyTailIdx_eq_take_drop _ rfl
-
-theorem modify_eq_take_cons_drop {f : α → α} {n} {l : List α} (h : n < l.length) :
-    modify f n l = take n l ++ f l[n] :: drop (n + 1) l := by
-  rw [modify_eq_take_drop, drop_eq_getElem_cons h]; rfl
-
-theorem exists_of_modify (f : α → α) {n} {l : List α} (h : n < l.length) :
-    ∃ l₁ a l₂, l = l₁ ++ a :: l₂ ∧ l₁.length = n ∧ modify f n l = l₁ ++ f a :: l₂ :=
-  match exists_of_modifyTailIdx _ (Nat.le_of_lt h) with
-  | ⟨_, _::_, eq, hl, H⟩ => ⟨_, _, _, eq, hl, H⟩
-  | ⟨_, [], eq, hl, _⟩ => nomatch Nat.ne_of_gt h (eq ▸ append_nil _ ▸ hl)
-
-@[simp] theorem modify_id (n) (l : List α) : l.modify id n = l := by
-  simp [modify]
-
-theorem take_modify (f : α → α) (n m) (l : List α) :
-    (modify f m l).take n = (take n l).modify f m := by
-  induction n generalizing l m with
-  | zero => simp
-  | succ n ih =>
-    cases l with
-    | nil => simp
-    | cons hd tl =>
-      cases m with
-      | zero => simp
-      | succ m => simp [ih]
-
-theorem drop_modify_of_lt (f : α → α) (n m) (l : List α) (h : n < m) :
-    (modify f n l).drop m = l.drop m := by
-  apply ext_getElem
-  · simp
-  · intro m' h₁ h₂
-    simp only [getElem_drop, getElem_modify, ite_eq_right_iff]
-    intro h'
-    omega
-
-theorem drop_modify_of_ge (f : α → α) (n m) (l : List α) (h : n ≥ m) :
-    (modify f n l).drop m = modify f (n - m) (drop m l) := by
-  apply ext_getElem
-  · simp
-  · intro m' h₁ h₂
-    simp [getElem_drop, getElem_modify, ite_eq_right_iff]
-    split <;> split <;> first | rfl | omega
-
-theorem eraseIdx_modify_of_eq (f : α → α) (n) (l : List α) :
-    (modify f n l).eraseIdx n = l.eraseIdx n := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro m h₁ h₂
-    simp only [getElem_eraseIdx, getElem_modify]
-    split <;> split <;> first | rfl | omega
-
-theorem eraseIdx_modify_of_lt (f : α → α) (i j) (l : List α) (h : j < i) :
-    (modify f i l).eraseIdx j = (l.eraseIdx j).modify f (i - 1) := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro k h₁ h₂
-    simp only [getElem_eraseIdx, getElem_modify]
-    by_cases h' : i - 1 = k
-    repeat' split
-    all_goals (first | rfl | omega)
-
-theorem eraseIdx_modify_of_gt (f : α → α) (i j) (l : List α) (h : j > i) :
-    (modify f i l).eraseIdx j = (l.eraseIdx j).modify f i := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro k h₁ h₂
-    simp only [getElem_eraseIdx, getElem_modify]
-    by_cases h' : i = k
-    repeat' split
-    all_goals (first | rfl | omega)
-
-theorem modify_eraseIdx_of_lt (f : α → α) (i j) (l : List α) (h : j < i) :
-    (l.eraseIdx i).modify f j = (l.modify f j).eraseIdx i := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro k h₁ h₂
-    simp only [getElem_eraseIdx, getElem_modify]
-    by_cases h' : j = k + 1
-    repeat' split
-    all_goals (first | rfl | omega)
-
-theorem modify_eraseIdx_of_ge (f : α → α) (i j) (l : List α) (h : j ≥ i) :
-    (l.eraseIdx i).modify f j = (l.modify f (j + 1)).eraseIdx i := by
-  apply ext_getElem
-  · simp [length_eraseIdx]
-  · intro k h₁ h₂
-    simp only [getElem_eraseIdx, getElem_modify]
-    by_cases h' : j + 1 = k + 1
-    repeat' split
-    all_goals (first | rfl | omega)
-
-end List

src/Init/Data/List/Nat/Range.lean

@@ -108,7 +108,7 @@ theorem range'_eq_append_iff : range' s n = xs ++ ys ↔ ∃ k, k ≤ n ∧ xs =
 
 @[simp] theorem find?_range'_eq_some {s n : Nat} {i : Nat} {p : Nat → Bool} :
     (range' s n).find? p = some i ↔ p i ∧ i ∈ range' s n ∧ ∀ j, s ≤ j → j < i → !p j := by
-  rw [find?_eq_some_iff_append]
+  rw [find?_eq_some]
   simp only [Bool.not_eq_eq_eq_not, Bool.not_true, exists_and_right, mem_range'_1,
     and_congr_right_iff]
   simp only [range'_eq_append_iff, eq_comm (a := i :: _), range'_eq_cons_iff]
@@ -169,7 +169,7 @@ 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
 
 theorem pairwise_lt_range (n : Nat) : Pairwise (· < ·) (range n) := by
-  simp +decide only [range_eq_range', pairwise_lt_range']
+  simp (config := {decide := true}) only [range_eq_range', pairwise_lt_range']
 
 theorem pairwise_le_range (n : Nat) : Pairwise (· ≤ ·) (range n) :=
   Pairwise.imp Nat.le_of_lt (pairwise_lt_range _)
@@ -177,10 +177,10 @@ theorem pairwise_le_range (n : Nat) : Pairwise (· ≤ ·) (range n) :=
 theorem take_range (m n : Nat) : take m (range n) = range (min m n) := by
   apply List.ext_getElem
   · simp
-  · simp +contextual [getElem_take, Nat.lt_min]
+  · simp (config := { contextual := true }) [getElem_take, Nat.lt_min]
 
 theorem nodup_range (n : Nat) : Nodup (range n) := by
-  simp +decide only [range_eq_range', nodup_range']
+  simp (config := {decide := true}) only [range_eq_range', nodup_range']
 
 @[simp] 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
@@ -282,7 +282,7 @@ theorem find?_iota_eq_none {n : Nat} {p : Nat → Bool} :
 
 @[simp] theorem find?_iota_eq_some {n : Nat} {i : Nat} {p : Nat → Bool} :
     (iota n).find? p = some i ↔ p i ∧ i ∈ iota n ∧ ∀ j, i < j → j ≤ n → !p j := by
-  rw [find?_eq_some_iff_append]
+  rw [find?_eq_some]
   simp only [iota_eq_reverse_range', reverse_eq_append_iff, reverse_cons, append_assoc, cons_append,
     nil_append, Bool.not_eq_eq_eq_not, Bool.not_true, exists_and_right, mem_reverse, mem_range'_1,
     and_congr_right_iff]
@@ -430,10 +430,7 @@ theorem enumFrom_eq_append_iff {l : List α} {n : Nat} :
 /-! ### enum -/
 
 @[simp]
-theorem enum_eq_nil_iff {l : List α} : List.enum l = [] ↔ l = [] := enumFrom_eq_nil
-
-@[deprecated enum_eq_nil_iff (since := "2024-11-04")]
-theorem enum_eq_nil {l : List α} : List.enum l = [] ↔ l = [] := enum_eq_nil_iff
+theorem enum_eq_nil {l : List α} : List.enum l = [] ↔ l = [] := enumFrom_eq_nil
 
 @[simp] theorem enum_singleton (x : α) : enum [x] = [(0, x)] := rfl
 

src/Init/Data/List/Nat/TakeDrop.lean

@@ -187,9 +187,6 @@ theorem take_add (l : List α) (m n : Nat) : l.take (m + n) = l.take m ++ (l.dro
   · apply length_take_le
   · apply Nat.le_add_right
 
-theorem take_one {l : List α} : l.take 1 = l.head?.toList := by
-  induction l <;> simp
-
 theorem dropLast_take {n : Nat} {l : List α} (h : n < l.length) :
     (l.take n).dropLast = l.take (n - 1) := by
   simp only [dropLast_eq_take, length_take, Nat.le_of_lt h, Nat.min_eq_left, take_take, sub_le]
@@ -285,14 +282,14 @@ theorem mem_drop_iff_getElem {l : List α} {a : α} :
   · rintro ⟨i, hm, rfl⟩
     refine ⟨i, by simp; omega, by rw [getElem_drop]⟩
 
-@[simp] theorem head?_drop (l : List α) (n : Nat) :
+theorem head?_drop (l : List α) (n : Nat) :
     (l.drop n).head? = l[n]? := by
   rw [head?_eq_getElem?, getElem?_drop, Nat.add_zero]
 
-@[simp] theorem head_drop {l : List α} {n : Nat} (h : l.drop n ≠ []) :
+theorem head_drop {l : List α} {n : Nat} (h : l.drop n ≠ []) :
     (l.drop n).head h = l[n]'(by simp_all) := by
   have w : n < l.length := length_lt_of_drop_ne_nil h
-  simp [getElem?_eq_getElem, h, w, head_eq_iff_head?_eq_some]
+  simpa [getElem?_eq_getElem, h, w, head_eq_iff_head?_eq_some] using head?_drop l n
 
 theorem getLast?_drop {l : List α} : (l.drop n).getLast? = if l.length ≤ n then none else l.getLast? := by
   rw [getLast?_eq_getElem?, getElem?_drop]
@@ -303,7 +300,7 @@ theorem getLast?_drop {l : List α} : (l.drop n).getLast? = if l.length ≤ n th
     congr
     omega
 
-@[simp] theorem getLast_drop {l : List α} (h : l.drop n ≠ []) :
+theorem getLast_drop {l : List α} (h : l.drop n ≠ []) :
     (l.drop n).getLast h = l.getLast (ne_nil_of_length_pos (by simp at h; omega)) := by
   simp only [ne_eq, drop_eq_nil_iff] at h
   apply Option.some_inj.1
@@ -452,26 +449,6 @@ theorem reverse_drop {l : List α} {n : Nat} :
     rw [w, take_zero, drop_of_length_le, reverse_nil]
     omega
 
-theorem take_add_one {l : List α} {n : Nat} :
-    l.take (n + 1) = l.take n ++ l[n]?.toList := by
-  simp [take_add, take_one]
-
-theorem drop_eq_getElem?_toList_append {l : List α} {n : Nat} :
-    l.drop n = l[n]?.toList ++ l.drop (n + 1) := by
-  induction l generalizing n with
-  | nil => simp
-  | cons hd tl ih =>
-    cases n
-    · simp
-    · simp only [drop_succ_cons, getElem?_cons_succ]
-      rw [ih]
-
-theorem drop_sub_one {l : List α} {n : Nat} (h : 0 < n) :
-    l.drop (n - 1) = l[n - 1]?.toList ++ l.drop n := by
-  rw [drop_eq_getElem?_toList_append]
-  congr
-  omega
-
 /-! ### findIdx -/
 
 theorem false_of_mem_take_findIdx {xs : List α} {p : α → Bool} (h : x ∈ xs.take (xs.findIdx p)) :

src/Init/Data/List/OfFn.lean

@@ -1,80 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Mario Carneiro, Kim Morrison
--/
-prelude
-import Init.Data.List.Basic
-import Init.Data.Fin.Fold
-
-/-!
-# Theorems about `List.ofFn`
--/
-
-namespace List
-
-/--
-`ofFn f` with `f : fin n → α` returns the list whose ith element is `f i`
-```
-ofFn f = [f 0, f 1, ... , f (n - 1)]
-```
--/
-def ofFn {n} (f : Fin n → α) : List α := Fin.foldr n (f · :: ·) []
-
-@[simp]
-theorem length_ofFn (f : Fin n → α) : (ofFn f).length = n := by
-  simp only [ofFn]
-  induction n with
-  | zero => simp
-  | succ n ih => simp [Fin.foldr_succ, ih]
-
-@[simp]
-protected theorem getElem_ofFn (f : Fin n → α) (i : Nat) (h : i < (ofFn f).length) :
-    (ofFn f)[i] = f ⟨i, by simp_all⟩ := by
-  simp only [ofFn]
-  induction n generalizing i with
-  | zero => simp at h
-  | succ n ih =>
-    match i with
-    | 0 => simp [Fin.foldr_succ]
-    | i+1 =>
-      simp only [Fin.foldr_succ]
-      apply ih
-      simp_all
-
-@[simp]
-protected theorem getElem?_ofFn (f : Fin n → α) (i) : (ofFn f)[i]? = if h : i < n then some (f ⟨i, h⟩) else none :=
-  if h : i < (ofFn f).length
-  then by
-    rw [getElem?_eq_getElem h, List.getElem_ofFn]
-    · simp only [length_ofFn] at h; simp [h]
-  else by
-    rw [dif_neg] <;>
-    simpa using h
-
-/-- `ofFn` on an empty domain is the empty list. -/
-@[simp]
-theorem ofFn_zero (f : Fin 0 → α) : ofFn f = [] :=
-  ext_get (by simp) (fun i hi₁ hi₂ => by contradiction)
-
-@[simp]
-theorem ofFn_succ {n} (f : Fin (n + 1) → α) : ofFn f = f 0 :: ofFn fun i => f i.succ :=
-  ext_get (by simp) (fun i hi₁ hi₂ => by
-    cases i
-    · simp
-    · simp)
-
-@[simp]
-theorem ofFn_eq_nil_iff {f : Fin n → α} : ofFn f = [] ↔ n = 0 := by
-  cases n <;> simp only [ofFn_zero, ofFn_succ, eq_self_iff_true, Nat.succ_ne_zero, reduceCtorEq]
-
-theorem head_ofFn {n} (f : Fin n → α) (h : ofFn f ≠ []) :
-    (ofFn f).head h = f ⟨0, Nat.pos_of_ne_zero (mt ofFn_eq_nil_iff.2 h)⟩ := by
-  rw [← getElem_zero (length_ofFn _ ▸ Nat.pos_of_ne_zero (mt ofFn_eq_nil_iff.2 h)),
-    List.getElem_ofFn]
-
-theorem getLast_ofFn {n} (f : Fin n → α) (h : ofFn f ≠ []) :
-    (ofFn f).getLast h = f ⟨n - 1, Nat.sub_one_lt (mt ofFn_eq_nil_iff.2 h)⟩ := by
-  simp [getLast_eq_getElem, length_ofFn, List.getElem_ofFn]
-
-end List

src/Init/Data/List/Pairwise.lean

@@ -76,11 +76,11 @@ theorem pairwise_of_forall {l : List α} (H : ∀ x y, R x y) : Pairwise R l :=
 
 theorem Pairwise.and_mem {l : List α} :
     Pairwise R l ↔ Pairwise (fun x y => x ∈ l ∧ y ∈ l ∧ R x y) l :=
-  Pairwise.iff_of_mem <| by simp +contextual
+  Pairwise.iff_of_mem <| by simp (config := { contextual := true })
 
 theorem Pairwise.imp_mem {l : List α} :
     Pairwise R l ↔ Pairwise (fun x y => x ∈ l → y ∈ l → R x y) l :=
-  Pairwise.iff_of_mem <| by simp +contextual
+  Pairwise.iff_of_mem <| by simp (config := { contextual := true })
 
 theorem Pairwise.forall_of_forall_of_flip (h₁ : ∀ x ∈ l, R x x) (h₂ : Pairwise R l)
     (h₃ : l.Pairwise (flip R)) : ∀ ⦃x⦄, x ∈ l → ∀ ⦃y⦄, y ∈ l → R x y := by

src/Init/Data/List/Perm.lean

@@ -114,14 +114,6 @@ theorem Perm.length_eq {l₁ l₂ : List α} (p : l₁ ~ l₂) : length l₁ = l
   | swap => rfl
   | trans _ _ ih₁ ih₂ => simp only [ih₁, ih₂]
 
-theorem Perm.contains_eq [BEq α] {l₁ l₂ : List α} (h : l₁ ~ l₂) {a : α} :
-    l₁.contains a = l₂.contains a := by
-  induction h with
-  | nil => rfl
-  | cons => simp_all
-  | swap => simp only [contains_cons, ← Bool.or_assoc, Bool.or_comm]
-  | trans => simp_all
-
 theorem Perm.eq_nil {l : List α} (p : l ~ []) : l = [] := eq_nil_of_length_eq_zero p.length_eq
 
 theorem Perm.nil_eq {l : List α} (p : [] ~ l) : [] = l := p.symm.eq_nil.symm

src/Init/Data/List/Sublist.lean

@@ -116,7 +116,7 @@ fun s => Subset.trans s <| subset_append_right _ _
 theorem replicate_subset {n : Nat} {a : α} {l : List α} : replicate n a ⊆ l ↔ n = 0 ∨ a ∈ l := by
   induction n with
   | zero => simp
-  | succ n ih => simp +contextual [replicate_succ, ih, cons_subset]
+  | succ n ih => simp (config := {contextual := true}) [replicate_succ, ih, cons_subset]
 
 theorem subset_replicate {n : Nat} {a : α} {l : List α} (h : n ≠ 0) : l ⊆ replicate n a ↔ ∀ x ∈ l, x = a := by
   induction l with
@@ -835,7 +835,7 @@ theorem isPrefix_iff : l₁ <+: l₂ ↔ ∀ i (h : i < l₁.length), l₂[i]? =
       simpa using ⟨0, by simp⟩
     | cons b l₂ =>
       simp only [cons_append, cons_prefix_cons, ih]
-      rw (occs := .pos [2]) [← Nat.and_forall_add_one]
+      rw (config := {occs := .pos [2]}) [← Nat.and_forall_add_one]
       simp [Nat.succ_lt_succ_iff, eq_comm]
 
 theorem isPrefix_iff_getElem {l₁ l₂ : List α} :

src/Init/Data/List/TakeDrop.lean

@@ -190,7 +190,7 @@ theorem set_drop {l : List α} {n m : Nat} {a : α} :
 theorem take_concat_get (l : List α) (i : Nat) (h : i < l.length) :
     (l.take i).concat l[i] = l.take (i+1) :=
   Eq.symm <| (append_left_inj _).1 <| (take_append_drop (i+1) l).trans <| by
-    rw [concat_eq_append, append_assoc, singleton_append, getElem_cons_drop_succ_eq_drop, take_append_drop]
+    rw [concat_eq_append, append_assoc, singleton_append, get_drop_eq_drop, take_append_drop]
 
 @[deprecated take_succ_cons (since := "2024-07-25")]
 theorem take_cons_succ : (a::as).take (i+1) = a :: as.take i := rfl

src/Init/Data/Nat/Basic.lean

@@ -490,10 +490,10 @@ protected theorem le_antisymm_iff {a b : Nat} : a = b ↔ a ≤ b ∧ b ≤ a :=
             (fun ⟨hle, hge⟩ => Nat.le_antisymm hle hge)
 protected theorem eq_iff_le_and_ge : ∀{a b : Nat}, a = b ↔ a ≤ b ∧ b ≤ a := @Nat.le_antisymm_iff
 
-instance : Std.Antisymm ( . ≤ . : Nat → Nat → Prop) where
+instance : Antisymm ( . ≤ . : Nat → Nat → Prop) where
   antisymm h₁ h₂ := Nat.le_antisymm h₁ h₂
 
-instance : Std.Antisymm (¬ . < . : Nat → Nat → Prop) where
+instance : Antisymm (¬ . < . : Nat → Nat → Prop) where
   antisymm h₁ h₂ := Nat.le_antisymm (Nat.ge_of_not_lt h₂) (Nat.ge_of_not_lt h₁)
 
 protected theorem add_le_add_left {n m : Nat} (h : n ≤ m) (k : Nat) : k + n ≤ k + m :=

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

@@ -357,7 +357,7 @@ theorem testBit_two_pow_of_ne {n m : Nat} (hm : n ≠ m) : testBit (2 ^ n) m = f
   | zero => simp
   | succ n =>
     rw [mod_eq_of_lt (a := 1) (Nat.one_lt_two_pow (by omega)), mod_two_eq_one_iff_testBit_zero, testBit_two_pow_sub_one ]
-    simp only [zero_lt_succ, decide_true]
+    simp only [zero_lt_succ, decide_True]
 
 @[simp] theorem mod_two_pos_mod_two_eq_one : x % 2 ^ j % 2 = 1 ↔ (0 < j) ∧ x % 2 = 1 := by
   rw [mod_two_eq_one_iff_testBit_zero, testBit_mod_two_pow]

src/Init/Data/Nat/Dvd.lean

@@ -92,7 +92,7 @@ protected theorem div_mul_cancel {n m : Nat} (H : n ∣ m) : m / n * n = m := by
   rw [Nat.mul_comm, Nat.mul_div_cancel' H]
 
 @[simp] theorem mod_mod_of_dvd (a : Nat) (h : c ∣ b) : a % b % c = a % c := by
-  rw (occs := .pos [2]) [← mod_add_div a b]
+  rw (config := {occs := .pos [2]}) [← mod_add_div a b]
   have ⟨x, h⟩ := h
   subst h
   rw [Nat.mul_assoc, add_mul_mod_self_left]

src/Init/Data/Nat/Lemmas.lean

@@ -32,77 +32,6 @@ namespace Nat
 @[simp] theorem exists_add_one_eq : (∃ n, n + 1 = a) ↔ 0 < a :=
   ⟨fun ⟨n, h⟩ => by omega, fun h => ⟨a - 1, by omega⟩⟩
 
-/-- Dependent variant of `forall_lt_succ_right`. -/
-theorem forall_lt_succ_right' {p : (m : Nat) → (m < n + 1) → Prop} :
-    (∀ m (h : m < n + 1), p m h) ↔ (∀ m (h : m < n), p m (by omega)) ∧ p n (by omega) := by
-  simp only [Nat.lt_succ_iff, Nat.le_iff_lt_or_eq]
-  constructor
-  · intro w
-    constructor
-    · intro m h
-      exact w _ (.inl h)
-    · exact w _ (.inr rfl)
-  · rintro w m (h|rfl)
-    · exact w.1 _ h
-    · exact w.2
-
-/-- See `forall_lt_succ_right'` for a variant where `p` takes the bound as an argument. -/
-theorem forall_lt_succ_right {p : Nat → Prop} :
-    (∀ m, m < n + 1 → p m) ↔ (∀ m, m < n → p m) ∧ p n := by
-  simpa using forall_lt_succ_right' (p := fun m _ => p m)
-
-/-- Dependent variant of `forall_lt_succ_left`. -/
-theorem forall_lt_succ_left' {p : (m : Nat) → (m < n + 1) → Prop} :
-    (∀ m (h : m < n + 1), p m h) ↔ p 0 (by omega) ∧ (∀ m (h : m < n), p (m + 1) (by omega)) := by
-  constructor
-  · intro w
-    constructor
-    · exact w 0 (by omega)
-    · intro m h
-      exact w (m + 1) (by omega)
-  · rintro ⟨h₀, h₁⟩ m h
-    cases m with
-    | zero => exact h₀
-    | succ m => exact h₁ m (by omega)
-
-/-- See `forall_lt_succ_left'` for a variant where `p` takes the bound as an argument. -/
-theorem forall_lt_succ_left {p : Nat → Prop} :
-    (∀ m, m < n + 1 → p m) ↔ p 0 ∧ (∀ m, m < n → p (m + 1)) := by
-  simpa using forall_lt_succ_left' (p := fun m _ => p m)
-
-/-- Dependent variant of `exists_lt_succ_right`. -/
-theorem exists_lt_succ_right' {p : (m : Nat) → (m < n + 1) → Prop} :
-    (∃ m, ∃ (h : m < n + 1), p m h) ↔ (∃ m, ∃ (h : m < n), p m (by omega)) ∨ p n (by omega) := by
-  simp only [Nat.lt_succ_iff, Nat.le_iff_lt_or_eq]
-  constructor
-  · rintro ⟨m, (h|rfl), w⟩
-    · exact .inl ⟨m, h, w⟩
-    · exact .inr w
-  · rintro (⟨m, h, w⟩ | w)
-    · exact ⟨m, by omega, w⟩
-    · exact ⟨n, by omega, w⟩
-
-/-- See `exists_lt_succ_right'` for a variant where `p` takes the bound as an argument. -/
-theorem exists_lt_succ_right {p : Nat → Prop} :
-    (∃ m, m < n + 1 ∧ p m) ↔ (∃ m, m < n ∧ p m) ∨ p n := by
-  simpa using exists_lt_succ_right' (p := fun m _ => p m)
-
-/-- Dependent variant of `exists_lt_succ_left`. -/
-theorem exists_lt_succ_left' {p : (m : Nat) → (m < n + 1) → Prop} :
-    (∃ m, ∃ (h : m < n + 1), p m h) ↔ p 0 (by omega) ∨ (∃ m, ∃ (h : m < n), p (m + 1) (by omega)) := by
-  constructor
-  · rintro ⟨_|m, h, w⟩
-    · exact .inl w
-    · exact .inr ⟨m, by omega, w⟩
-  · rintro (w|⟨m, h, w⟩)
-    · exact ⟨0, by omega, w⟩
-    · exact ⟨m + 1, by omega, w⟩
-
-/-- See `exists_lt_succ_left'` for a variant where `p` takes the bound as an argument. -/
-theorem exists_lt_succ_left {p : Nat → Prop} :
-    (∃ m, m < n + 1 ∧ p m) ↔ p 0 ∨ (∃ m, m < n ∧ p (m + 1)) := by
-  simpa using exists_lt_succ_left' (p := fun m _ => p m)
-
 /-! ## add -/
 
 protected theorem add_add_add_comm (a b c d : Nat) : (a + b) + (c + d) = (a + c) + (b + d) := by
@@ -651,8 +580,8 @@ theorem sub_mul_mod {x k n : Nat} (h₁ : n*k ≤ x) : (x - n*k) % n = x % n :=
   | .inr npos => Nat.mod_eq_of_lt (mod_lt _ npos)
 
 theorem mul_mod (a b n : Nat) : a * b % n = (a % n) * (b % n) % n := by
-  rw (occs := .pos [1]) [← mod_add_div a n]
-  rw (occs := .pos [1]) [← mod_add_div b n]
+  rw (config := {occs := .pos [1]}) [← mod_add_div a n]
+  rw (config := {occs := .pos [1]}) [← mod_add_div b n]
   rw [Nat.add_mul, Nat.mul_add, Nat.mul_add,
     Nat.mul_assoc, Nat.mul_assoc, ← Nat.mul_add n, add_mul_mod_self_left,
     Nat.mul_comm _ (n * (b / n)), Nat.mul_assoc, add_mul_mod_self_left]
@@ -873,10 +802,6 @@ theorem le_log2 (h : n ≠ 0) : k ≤ n.log2 ↔ 2 ^ k ≤ n := by
 theorem log2_lt (h : n ≠ 0) : n.log2 < k ↔ n < 2 ^ k := by
   rw [← Nat.not_le, ← Nat.not_le, le_log2 h]
 
-@[simp]
-theorem log2_two_pow : (2 ^ n).log2 = n := by
-  apply Nat.eq_of_le_of_lt_succ <;> simp [le_log2, log2_lt, NeZero.ne, Nat.pow_lt_pow_iff_right]
-
 theorem log2_self_le (h : n ≠ 0) : 2 ^ n.log2 ≤ n := (le_log2 h).1 (Nat.le_refl _)
 
 theorem lt_log2_self : n < 2 ^ (n.log2 + 1) :=

src/Init/Data/OfScientific.lean

@@ -10,10 +10,8 @@ import Init.Data.Nat.Log2
 
 /-- For decimal and scientific numbers (e.g., `1.23`, `3.12e10`).
    Examples:
-   - `1.23` is syntax for `OfScientific.ofScientific (nat_lit 123) true (nat_lit 2)`
-   - `121e100` is syntax for `OfScientific.ofScientific (nat_lit 121) false (nat_lit 100)`
-
-   Note the use of `nat_lit`; there is no wrapping `OfNat.ofNat` in the resulting term.
+   - `OfScientific.ofScientific 123 true 2`    represents `1.23`
+   - `OfScientific.ofScientific 121 false 100` represents `121e100`
 -/
 class OfScientific (α : Type u) where
   ofScientific (mantissa : Nat) (exponentSign : Bool) (decimalExponent : Nat) : α

src/Init/Data/Option/Attach.lean

@@ -44,7 +44,7 @@ theorem attach_congr {o₁ o₂ : Option α} (h : o₁ = o₂) :
   simp
 
 theorem attachWith_congr {o₁ o₂ : Option α} (w : o₁ = o₂) {P : α → Prop} {H : ∀ x ∈ o₁, P x} :
-    o₁.attachWith P H = o₂.attachWith P fun _ h => H _ (w ▸ h) := by
+    o₁.attachWith P H = o₂.attachWith P fun x h => H _ (w ▸ h) := by
   subst w
   simp
 
@@ -128,12 +128,12 @@ theorem attach_map {o : Option α} (f : α → β) :
   cases o <;> simp
 
 theorem attachWith_map {o : Option α} (f : α → β) {P : β → Prop} {H : ∀ (b : β), b ∈ o.map f → P b} :
-    (o.map f).attachWith P H = (o.attachWith (P ∘ f) (fun _ h => H _ (mem_map_of_mem f h))).map
+    (o.map f).attachWith P H = (o.attachWith (P ∘ f) (fun a h => H _ (mem_map_of_mem f h))).map
       fun ⟨x, h⟩ => ⟨f x, h⟩ := by
   cases o <;> simp
 
 theorem map_attach {o : Option α} (f : { x // x ∈ o } → β) :
-    o.attach.map f = o.pmap (fun a (h : a ∈ o) => f ⟨a, h⟩) (fun _ h => h) := by
+    o.attach.map f = o.pmap (fun a (h : a ∈ o) => f ⟨a, h⟩) (fun a h => h) := by
   cases o <;> simp
 
 theorem map_attachWith {o : Option α} {P : α → Prop} {H : ∀ (a : α), a ∈ o → P a}

src/Init/Data/Option/Basic.lean

@@ -4,7 +4,9 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Leonardo de Moura, Mario Carneiro
 -/
 prelude
+import Init.Core
 import Init.Control.Basic
+import Init.Coe
 
 namespace Option
 
@@ -25,9 +27,6 @@ def toMonad [Monad m] [Alternative m] : Option α → m α := getM
   | some _ => true
   | none   => false
 
-@[simp] theorem isSome_none : @isSome α none = false := rfl
-@[simp] theorem isSome_some : isSome (some a) = true := rfl
-
 @[deprecated isSome (since := "2024-04-17"), inline] def toBool : Option α → Bool := isSome
 
 /-- Returns `true` on `none` and `false` on `some x`. -/
@@ -35,9 +34,6 @@ def toMonad [Monad m] [Alternative m] : Option α → m α := getM
   | some _ => false
   | none   => true
 
-@[simp] theorem isNone_none : @isNone α none = true := rfl
-@[simp] theorem isNone_some : isNone (some a) = false := rfl
-
 /--
 `x?.isEqSome y` is equivalent to `x? == some y`, but avoids an allocation.
 -/
@@ -140,10 +136,6 @@ def merge (fn : α → α → α) : Option α → Option α → Option α
 @[inline] def get {α : Type u} : (o : Option α) → isSome o → α
   | some x, _ => x
 
-@[simp] theorem some_get : ∀ {x : Option α} (h : isSome x), some (x.get h) = x
-| some _, _ => rfl
-@[simp] theorem get_some (x : α) (h : isSome (some x)) : (some x).get h = x := rfl
-
 /-- `guard p a` returns `some a` if `p a` holds, otherwise `none`. -/
 @[inline] def guard (p : α → Prop) [DecidablePred p] (a : α) : Option α :=
   if p a then some a else none

src/Init/Data/Option/Instances.lean

@@ -86,6 +86,4 @@ instance : ForIn' m (Option α) α inferInstance where
       match ← f a rfl init with
       | .done r | .yield r => return r
 
--- No separate `ForIn` instance is required because it can be derived from `ForIn'`.
-
 end Option

src/Init/Data/Option/Lemmas.lean

@@ -36,6 +36,11 @@ theorem get_of_mem : ∀ {o : Option α} (h : isSome o), a ∈ o → o.get h = a
 
 theorem not_mem_none (a : α) : a ∉ (none : Option α) := nofun
 
+@[simp] theorem some_get : ∀ {x : Option α} (h : isSome x), some (x.get h) = x
+| some _, _ => rfl
+
+@[simp] theorem get_some (x : α) (h : isSome (some x)) : (some x).get h = x := rfl
+
 theorem getD_of_ne_none {x : Option α} (hx : x ≠ none) (y : α) : some (x.getD y) = x := by
   cases x; {contradiction}; rw [getD_some]
 
@@ -68,11 +73,19 @@ theorem mem_unique {o : Option α} {a b : α} (ha : a ∈ o) (hb : b ∈ o) : a
 theorem eq_none_iff_forall_not_mem : o = none ↔ ∀ a, a ∉ o :=
   ⟨fun e a h => by rw [e] at h; (cases h), fun h => ext <| by simp; exact h⟩
 
+@[simp] theorem isSome_none : @isSome α none = false := rfl
+
+@[simp] theorem isSome_some : isSome (some a) = true := rfl
+
 theorem isSome_iff_exists : isSome x ↔ ∃ a, x = some a := by cases x <;> simp [isSome]
 
 theorem isSome_eq_isSome : (isSome x = isSome y) ↔ (x = none ↔ y = none) := by
   cases x <;> cases y <;> simp
 
+@[simp] theorem isNone_none : @isNone α none = true := rfl
+
+@[simp] theorem isNone_some : isNone (some a) = false := rfl
+
 @[simp] theorem not_isSome : isSome a = false ↔ a.isNone = true := by
   cases a <;> simp
 
@@ -361,15 +374,9 @@ end choice
 
 -- See `Init.Data.Option.List` for lemmas about `toList`.
 
-@[simp] theorem some_or : (some a).or o = some a := rfl
+@[simp] theorem or_some : (some a).or o = some a := rfl
 @[simp] theorem none_or : none.or o = o := rfl
 
-@[deprecated some_or (since := "2024-11-03")] theorem or_some : (some a).or o = some a := rfl
-
-/-- This will be renamed to `or_some` once the existing deprecated lemma is removed. -/
-@[simp] theorem or_some' {o : Option α} : o.or (some a) = o.getD a := by
-  cases o <;> rfl
-
 theorem or_eq_bif : or o o' = bif o.isSome then o else o' := by
   cases o <;> rfl
 

src/Init/Data/Option/List.lean

@@ -11,28 +11,4 @@ namespace Option
 @[simp] theorem mem_toList {a : α} {o : Option α} : a ∈ o.toList ↔ a ∈ o := by
   cases o <;> simp [eq_comm]
 
-@[simp] theorem forIn'_none [Monad m] (b : β) (f : (a : α) → a ∈ none → β → m (ForInStep β)) :
-    forIn' none b f = pure b := by
-  rfl
-
-@[simp] theorem forIn'_some [Monad m] (a : α) (b : β) (f : (a' : α) → a' ∈ some a → β → m (ForInStep β)) :
-    forIn' (some a) b f = bind (f a rfl b) (fun | .done r | .yield r => pure r) := by
-  rfl
-
-@[simp] theorem forIn_none [Monad m] (b : β) (f : α → β → m (ForInStep β)) :
-    forIn none b f = pure b := by
-  rfl
-
-@[simp] theorem forIn_some [Monad m] (a : α) (b : β) (f : α → β → m (ForInStep β)) :
-    forIn (some a) b f = bind (f a b) (fun | .done r | .yield r => pure r) := by
-  rfl
-
-@[simp] theorem forIn'_toList [Monad m] (o : Option α) (b : β) (f : (a : α) → a ∈ o.toList → β → m (ForInStep β)) :
-    forIn' o.toList b f = forIn' o b fun a m b => f a (by simpa using m) b := by
-  cases o <;> rfl
-
-@[simp] theorem forIn_toList [Monad m] (o : Option α) (b : β) (f : α → β → m (ForInStep β)) :
-    forIn o.toList b f = forIn o b f := by
-  cases o <;> rfl
-
 end Option

src/Init/Data/Range.lean

@@ -20,6 +20,21 @@ instance : Membership Nat Range where
 namespace Range
 universe u v
 
+@[inline] protected def forIn {β : Type u} {m : Type u → Type v} [Monad m] (range : Range) (init : β) (f : Nat → β → m (ForInStep β)) : m β :=
+  -- pass `stop` and `step` separately so the `range` object can be eliminated through inlining
+  let rec @[specialize] loop (fuel i stop step : Nat) (b : β) : m β := do
+    if i ≥ stop then
+      return b
+    else match fuel with
+     | 0   => pure b
+     | fuel+1 => match (← f i b) with
+        | ForInStep.done b  => pure b
+        | ForInStep.yield b => loop fuel (i + step) stop step b
+  loop range.stop range.start range.stop range.step init
+
+instance : ForIn m Range Nat where
+  forIn := Range.forIn
+
 @[inline] protected def forIn' {β : Type u} {m : Type u → Type v} [Monad m] (range : Range) (init : β) (f : (i : Nat) → i ∈ range → β → m (ForInStep β)) : m β :=
   let rec @[specialize] loop (start stop step : Nat) (f : (i : Nat) → start ≤ i ∧ i < stop → β → m (ForInStep β)) (fuel i : Nat) (hl : start ≤ i) (b : β) : m β := do
     if hu : i < stop then
@@ -35,8 +50,6 @@ universe u v
 instance : ForIn' m Range Nat inferInstance where
   forIn' := Range.forIn'
 
--- No separate `ForIn` instance is required because it can be derived from `ForIn'`.
-
 @[inline] protected def forM {m : Type u → Type v} [Monad m] (range : Range) (f : Nat → m PUnit) : m PUnit :=
   let rec @[specialize] loop (fuel i stop step : Nat) : m PUnit := do
     if i ≥ stop then

src/Init/Data/Repr.lean

@@ -5,6 +5,10 @@ Author: Leonardo de Moura
 -/
 prelude
 import Init.Data.Format.Basic
+import Init.Data.Int.Basic
+import Init.Data.Nat.Div
+import Init.Data.UInt.BasicAux
+import Init.Control.Id
 open Sum Subtype Nat
 
 open Std
@@ -162,7 +166,7 @@ private def reprArray : Array String := Id.run do
   List.range 128 |>.map (·.toUSize.repr) |> Array.mk
 
 private def reprFast (n : Nat) : String :=
-  if h : n < 128 then Nat.reprArray.get n h else
+  if h : n < 128 then Nat.reprArray.get ⟨n, h⟩ else
   if h : n < USize.size then (USize.ofNatCore n h).repr
   else (toDigits 10 n).asString
 

src/Init/Data/SInt.lean

@@ -1,11 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Henrik Böving
--/
-prelude
-import Init.Data.SInt.Basic
-
-/-!
-This module contains the definitions and basic theory about signed fixed width integer types.
--/

src/Init/Data/SInt/Basic.lean

@@ -1,588 +0,0 @@
-/-
-Copyright (c) 2024 Lean FRO, LLC. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Henrik Böving
--/
-prelude
-import Init.Data.UInt.Basic
-
-/-!
-This module contains the definition of signed fixed width integer types as well as basic arithmetic
-and bitwise operations on top of it.
--/
-
-
-/--
-The type of signed 8-bit integers. This type has special support in the
-compiler to make it actually 8 bits rather than wrapping a `Nat`.
--/
-structure Int8 where
-  /--
-  Obtain the `UInt8` that is 2's complement equivalent to the `Int8`.
-  -/
-  toUInt8 : UInt8
-
-/--
-The type of signed 16-bit integers. This type has special support in the
-compiler to make it actually 16 bits rather than wrapping a `Nat`.
--/
-structure Int16 where
-  /--
-  Obtain the `UInt16` that is 2's complement equivalent to the `Int16`.
-  -/
-  toUInt16 : UInt16
-
-/--
-The type of signed 32-bit integers. This type has special support in the
-compiler to make it actually 32 bits rather than wrapping a `Nat`.
--/
-structure Int32 where
-  /--
-  Obtain the `UInt32` that is 2's complement equivalent to the `Int32`.
-  -/
-  toUInt32 : UInt32
-
-/--
-The type of signed 64-bit integers. This type has special support in the
-compiler to make it actually 64 bits rather than wrapping a `Nat`.
--/
-structure Int64 where
-  /--
-  Obtain the `UInt64` that is 2's complement equivalent to the `Int64`.
-  -/
-  toUInt64 : UInt64
-
-/--
-A `ISize` is a signed integer with the size of a word for the platform's architecture.
-
-For example, if running on a 32-bit machine, ISize is equivalent to `Int32`.
-Or on a 64-bit machine, `Int64`.
--/
-structure ISize where
-  /--
-  Obtain the `USize` that is 2's complement equivalent to the `ISize`.
-  -/
-  toUSize : USize
-
-/-- The size of type `Int8`, that is, `2^8 = 256`. -/
-abbrev Int8.size : Nat := 256
-
-/--
-Obtain the `BitVec` that contains the 2's complement representation of the `Int8`.
--/
-@[inline] def Int8.toBitVec (x : Int8) : BitVec 8 := x.toUInt8.toBitVec
-
-@[extern "lean_int8_of_int"]
-def Int8.ofInt (i : @& Int) : Int8 := ⟨⟨BitVec.ofInt 8 i⟩⟩
-@[extern "lean_int8_of_nat"]
-def Int8.ofNat (n : @& Nat) : Int8 := ⟨⟨BitVec.ofNat 8 n⟩⟩
-abbrev Int.toInt8 := Int8.ofInt
-abbrev Nat.toInt8 := Int8.ofNat
-@[extern "lean_int8_to_int"]
-def Int8.toInt (i : Int8) : Int := i.toBitVec.toInt
-/--
-This function has the same behavior as `Int.toNat` for negative numbers.
-If you want to obtain the 2's complement representation use `toBitVec`.
--/
-@[inline] def Int8.toNat (i : Int8) : Nat := i.toInt.toNat
-@[extern "lean_int8_neg"]
-def Int8.neg (i : Int8) : Int8 := ⟨⟨-i.toBitVec⟩⟩
-
-instance : ToString Int8 where
-  toString i := toString i.toInt
-
-instance : OfNat Int8 n := ⟨Int8.ofNat n⟩
-instance : Neg Int8 where
-  neg := Int8.neg
-
-@[extern "lean_int8_add"]
-def Int8.add (a b : Int8) : Int8 := ⟨⟨a.toBitVec + b.toBitVec⟩⟩
-@[extern "lean_int8_sub"]
-def Int8.sub (a b : Int8) : Int8 := ⟨⟨a.toBitVec - b.toBitVec⟩⟩
-@[extern "lean_int8_mul"]
-def Int8.mul (a b : Int8) : Int8 := ⟨⟨a.toBitVec * b.toBitVec⟩⟩
-@[extern "lean_int8_div"]
-def Int8.div (a b : Int8) : Int8 := ⟨⟨BitVec.sdiv a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int8_mod"]
-def Int8.mod (a b : Int8) : Int8 := ⟨⟨BitVec.srem a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int8_land"]
-def Int8.land (a b : Int8) : Int8 := ⟨⟨a.toBitVec &&& b.toBitVec⟩⟩
-@[extern "lean_int8_lor"]
-def Int8.lor (a b : Int8) : Int8 := ⟨⟨a.toBitVec ||| b.toBitVec⟩⟩
-@[extern "lean_int8_xor"]
-def Int8.xor (a b : Int8) : Int8 := ⟨⟨a.toBitVec ^^^ b.toBitVec⟩⟩
-@[extern "lean_int8_shift_left"]
-def Int8.shiftLeft (a b : Int8) : Int8 := ⟨⟨a.toBitVec <<< (b.toBitVec.smod 8)⟩⟩
-@[extern "lean_int8_shift_right"]
-def Int8.shiftRight (a b : Int8) : Int8 := ⟨⟨BitVec.sshiftRight' a.toBitVec (b.toBitVec.smod 8)⟩⟩
-@[extern "lean_int8_complement"]
-def Int8.complement (a : Int8) : Int8 := ⟨⟨~~~a.toBitVec⟩⟩
-
-@[extern "lean_int8_dec_eq"]
-def Int8.decEq (a b : Int8) : Decidable (a = b) :=
-  match a, b with
-  | ⟨n⟩, ⟨m⟩ =>
-    if h : n = m then
-      isTrue <| h ▸ rfl
-    else
-      isFalse (fun h' => Int8.noConfusion h' (fun h' => absurd h' h))
-
-def Int8.lt (a b : Int8) : Prop := a.toBitVec.slt b.toBitVec
-def Int8.le (a b : Int8) : Prop := a.toBitVec.sle b.toBitVec
-
-instance : Inhabited Int8 where
-  default := 0
-
-instance : Add Int8         := ⟨Int8.add⟩
-instance : Sub Int8         := ⟨Int8.sub⟩
-instance : Mul Int8         := ⟨Int8.mul⟩
-instance : Mod Int8         := ⟨Int8.mod⟩
-instance : Div Int8         := ⟨Int8.div⟩
-instance : LT Int8          := ⟨Int8.lt⟩
-instance : LE Int8          := ⟨Int8.le⟩
-instance : Complement Int8  := ⟨Int8.complement⟩
-instance : AndOp Int8       := ⟨Int8.land⟩
-instance : OrOp Int8        := ⟨Int8.lor⟩
-instance : Xor Int8         := ⟨Int8.xor⟩
-instance : ShiftLeft Int8   := ⟨Int8.shiftLeft⟩
-instance : ShiftRight Int8  := ⟨Int8.shiftRight⟩
-instance : DecidableEq Int8 := Int8.decEq
-
-@[extern "lean_int8_dec_lt"]
-def Int8.decLt (a b : Int8) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec.slt b.toBitVec))
-
-@[extern "lean_int8_dec_le"]
-def Int8.decLe (a b : Int8) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec.sle b.toBitVec))
-
-instance (a b : Int8) : Decidable (a < b) := Int8.decLt a b
-instance (a b : Int8) : Decidable (a ≤ b) := Int8.decLe a b
-instance : Max Int8 := maxOfLe
-instance : Min Int8 := minOfLe
-
-/-- The size of type `Int16`, that is, `2^16 = 65536`. -/
-abbrev Int16.size : Nat := 65536
-
-/--
-Obtain the `BitVec` that contains the 2's complement representation of the `Int16`.
--/
-@[inline] def Int16.toBitVec (x : Int16) : BitVec 16 := x.toUInt16.toBitVec
-
-@[extern "lean_int16_of_int"]
-def Int16.ofInt (i : @& Int) : Int16 := ⟨⟨BitVec.ofInt 16 i⟩⟩
-@[extern "lean_int16_of_nat"]
-def Int16.ofNat (n : @& Nat) : Int16 := ⟨⟨BitVec.ofNat 16 n⟩⟩
-abbrev Int.toInt16 := Int16.ofInt
-abbrev Nat.toInt16 := Int16.ofNat
-@[extern "lean_int16_to_int"]
-def Int16.toInt (i : Int16) : Int := i.toBitVec.toInt
-/--
-This function has the same behavior as `Int.toNat` for negative numbers.
-If you want to obtain the 2's complement representation use `toBitVec`.
--/
-@[inline] def Int16.toNat (i : Int16) : Nat := i.toInt.toNat
-@[extern "lean_int16_to_int8"]
-def Int16.toInt8 (a : Int16) : Int8 := ⟨⟨a.toBitVec.signExtend 8⟩⟩
-@[extern "lean_int8_to_int16"]
-def Int8.toInt16 (a : Int8) : Int16 := ⟨⟨a.toBitVec.signExtend 16⟩⟩
-@[extern "lean_int16_neg"]
-def Int16.neg (i : Int16) : Int16 := ⟨⟨-i.toBitVec⟩⟩
-
-instance : ToString Int16 where
-  toString i := toString i.toInt
-
-instance : OfNat Int16 n := ⟨Int16.ofNat n⟩
-instance : Neg Int16 where
-  neg := Int16.neg
-
-@[extern "lean_int16_add"]
-def Int16.add (a b : Int16) : Int16 := ⟨⟨a.toBitVec + b.toBitVec⟩⟩
-@[extern "lean_int16_sub"]
-def Int16.sub (a b : Int16) : Int16 := ⟨⟨a.toBitVec - b.toBitVec⟩⟩
-@[extern "lean_int16_mul"]
-def Int16.mul (a b : Int16) : Int16 := ⟨⟨a.toBitVec * b.toBitVec⟩⟩
-@[extern "lean_int16_div"]
-def Int16.div (a b : Int16) : Int16 := ⟨⟨BitVec.sdiv a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int16_mod"]
-def Int16.mod (a b : Int16) : Int16 := ⟨⟨BitVec.srem a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int16_land"]
-def Int16.land (a b : Int16) : Int16 := ⟨⟨a.toBitVec &&& b.toBitVec⟩⟩
-@[extern "lean_int16_lor"]
-def Int16.lor (a b : Int16) : Int16 := ⟨⟨a.toBitVec ||| b.toBitVec⟩⟩
-@[extern "lean_int16_xor"]
-def Int16.xor (a b : Int16) : Int16 := ⟨⟨a.toBitVec ^^^ b.toBitVec⟩⟩
-@[extern "lean_int16_shift_left"]
-def Int16.shiftLeft (a b : Int16) : Int16 := ⟨⟨a.toBitVec <<< (b.toBitVec.smod 16)⟩⟩
-@[extern "lean_int16_shift_right"]
-def Int16.shiftRight (a b : Int16) : Int16 := ⟨⟨BitVec.sshiftRight' a.toBitVec (b.toBitVec.smod 16)⟩⟩
-@[extern "lean_int16_complement"]
-def Int16.complement (a : Int16) : Int16 := ⟨⟨~~~a.toBitVec⟩⟩
-
-@[extern "lean_int16_dec_eq"]
-def Int16.decEq (a b : Int16) : Decidable (a = b) :=
-  match a, b with
-  | ⟨n⟩, ⟨m⟩ =>
-    if h : n = m then
-      isTrue <| h ▸ rfl
-    else
-      isFalse (fun h' => Int16.noConfusion h' (fun h' => absurd h' h))
-
-def Int16.lt (a b : Int16) : Prop := a.toBitVec.slt b.toBitVec
-def Int16.le (a b : Int16) : Prop := a.toBitVec.sle b.toBitVec
-
-instance : Inhabited Int16 where
-  default := 0
-
-instance : Add Int16         := ⟨Int16.add⟩
-instance : Sub Int16         := ⟨Int16.sub⟩
-instance : Mul Int16         := ⟨Int16.mul⟩
-instance : Mod Int16         := ⟨Int16.mod⟩
-instance : Div Int16         := ⟨Int16.div⟩
-instance : LT Int16          := ⟨Int16.lt⟩
-instance : LE Int16          := ⟨Int16.le⟩
-instance : Complement Int16  := ⟨Int16.complement⟩
-instance : AndOp Int16       := ⟨Int16.land⟩
-instance : OrOp Int16        := ⟨Int16.lor⟩
-instance : Xor Int16         := ⟨Int16.xor⟩
-instance : ShiftLeft Int16   := ⟨Int16.shiftLeft⟩
-instance : ShiftRight Int16  := ⟨Int16.shiftRight⟩
-instance : DecidableEq Int16 := Int16.decEq
-
-@[extern "lean_int16_dec_lt"]
-def Int16.decLt (a b : Int16) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec.slt b.toBitVec))
-
-@[extern "lean_int16_dec_le"]
-def Int16.decLe (a b : Int16) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec.sle b.toBitVec))
-
-instance (a b : Int16) : Decidable (a < b) := Int16.decLt a b
-instance (a b : Int16) : Decidable (a ≤ b) := Int16.decLe a b
-instance : Max Int16 := maxOfLe
-instance : Min Int16 := minOfLe
-
-/-- The size of type `Int32`, that is, `2^32 = 4294967296`. -/
-abbrev Int32.size : Nat := 4294967296
-
-/--
-Obtain the `BitVec` that contains the 2's complement representation of the `Int32`.
--/
-@[inline] def Int32.toBitVec (x : Int32) : BitVec 32 := x.toUInt32.toBitVec
-
-@[extern "lean_int32_of_int"]
-def Int32.ofInt (i : @& Int) : Int32 := ⟨⟨BitVec.ofInt 32 i⟩⟩
-@[extern "lean_int32_of_nat"]
-def Int32.ofNat (n : @& Nat) : Int32 := ⟨⟨BitVec.ofNat 32 n⟩⟩
-abbrev Int.toInt32 := Int32.ofInt
-abbrev Nat.toInt32 := Int32.ofNat
-@[extern "lean_int32_to_int"]
-def Int32.toInt (i : Int32) : Int := i.toBitVec.toInt
-/--
-This function has the same behavior as `Int.toNat` for negative numbers.
-If you want to obtain the 2's complement representation use `toBitVec`.
--/
-@[inline] def Int32.toNat (i : Int32) : Nat := i.toInt.toNat
-@[extern "lean_int32_to_int8"]
-def Int32.toInt8 (a : Int32) : Int8 := ⟨⟨a.toBitVec.signExtend 8⟩⟩
-@[extern "lean_int32_to_int16"]
-def Int32.toInt16 (a : Int32) : Int16 := ⟨⟨a.toBitVec.signExtend 16⟩⟩
-@[extern "lean_int8_to_int32"]
-def Int8.toInt32 (a : Int8) : Int32 := ⟨⟨a.toBitVec.signExtend 32⟩⟩
-@[extern "lean_int16_to_int32"]
-def Int16.toInt32 (a : Int16) : Int32 := ⟨⟨a.toBitVec.signExtend 32⟩⟩
-@[extern "lean_int32_neg"]
-def Int32.neg (i : Int32) : Int32 := ⟨⟨-i.toBitVec⟩⟩
-
-instance : ToString Int32 where
-  toString i := toString i.toInt
-
-instance : OfNat Int32 n := ⟨Int32.ofNat n⟩
-instance : Neg Int32 where
-  neg := Int32.neg
-
-@[extern "lean_int32_add"]
-def Int32.add (a b : Int32) : Int32 := ⟨⟨a.toBitVec + b.toBitVec⟩⟩
-@[extern "lean_int32_sub"]
-def Int32.sub (a b : Int32) : Int32 := ⟨⟨a.toBitVec - b.toBitVec⟩⟩
-@[extern "lean_int32_mul"]
-def Int32.mul (a b : Int32) : Int32 := ⟨⟨a.toBitVec * b.toBitVec⟩⟩
-@[extern "lean_int32_div"]
-def Int32.div (a b : Int32) : Int32 := ⟨⟨BitVec.sdiv a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int32_mod"]
-def Int32.mod (a b : Int32) : Int32 := ⟨⟨BitVec.srem a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int32_land"]
-def Int32.land (a b : Int32) : Int32 := ⟨⟨a.toBitVec &&& b.toBitVec⟩⟩
-@[extern "lean_int32_lor"]
-def Int32.lor (a b : Int32) : Int32 := ⟨⟨a.toBitVec ||| b.toBitVec⟩⟩
-@[extern "lean_int32_xor"]
-def Int32.xor (a b : Int32) : Int32 := ⟨⟨a.toBitVec ^^^ b.toBitVec⟩⟩
-@[extern "lean_int32_shift_left"]
-def Int32.shiftLeft (a b : Int32) : Int32 := ⟨⟨a.toBitVec <<< (b.toBitVec.smod 32)⟩⟩
-@[extern "lean_int32_shift_right"]
-def Int32.shiftRight (a b : Int32) : Int32 := ⟨⟨BitVec.sshiftRight' a.toBitVec (b.toBitVec.smod 32)⟩⟩
-@[extern "lean_int32_complement"]
-def Int32.complement (a : Int32) : Int32 := ⟨⟨~~~a.toBitVec⟩⟩
-
-@[extern "lean_int32_dec_eq"]
-def Int32.decEq (a b : Int32) : Decidable (a = b) :=
-  match a, b with
-  | ⟨n⟩, ⟨m⟩ =>
-    if h : n = m then
-      isTrue <| h ▸ rfl
-    else
-      isFalse (fun h' => Int32.noConfusion h' (fun h' => absurd h' h))
-
-def Int32.lt (a b : Int32) : Prop := a.toBitVec.slt b.toBitVec
-def Int32.le (a b : Int32) : Prop := a.toBitVec.sle b.toBitVec
-
-instance : Inhabited Int32 where
-  default := 0
-
-instance : Add Int32         := ⟨Int32.add⟩
-instance : Sub Int32         := ⟨Int32.sub⟩
-instance : Mul Int32         := ⟨Int32.mul⟩
-instance : Mod Int32         := ⟨Int32.mod⟩
-instance : Div Int32         := ⟨Int32.div⟩
-instance : LT Int32          := ⟨Int32.lt⟩
-instance : LE Int32          := ⟨Int32.le⟩
-instance : Complement Int32  := ⟨Int32.complement⟩
-instance : AndOp Int32       := ⟨Int32.land⟩
-instance : OrOp Int32        := ⟨Int32.lor⟩
-instance : Xor Int32         := ⟨Int32.xor⟩
-instance : ShiftLeft Int32   := ⟨Int32.shiftLeft⟩
-instance : ShiftRight Int32  := ⟨Int32.shiftRight⟩
-instance : DecidableEq Int32 := Int32.decEq
-
-@[extern "lean_int32_dec_lt"]
-def Int32.decLt (a b : Int32) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec.slt b.toBitVec))
-
-@[extern "lean_int32_dec_le"]
-def Int32.decLe (a b : Int32) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec.sle b.toBitVec))
-
-instance (a b : Int32) : Decidable (a < b) := Int32.decLt a b
-instance (a b : Int32) : Decidable (a ≤ b) := Int32.decLe a b
-instance : Max Int32 := maxOfLe
-instance : Min Int32 := minOfLe
-
-/-- The size of type `Int64`, that is, `2^64 = 18446744073709551616`. -/
-abbrev Int64.size : Nat := 18446744073709551616
-
-/--
-Obtain the `BitVec` that contains the 2's complement representation of the `Int64`.
--/
-@[inline] def Int64.toBitVec (x : Int64) : BitVec 64 := x.toUInt64.toBitVec
-
-@[extern "lean_int64_of_int"]
-def Int64.ofInt (i : @& Int) : Int64 := ⟨⟨BitVec.ofInt 64 i⟩⟩
-@[extern "lean_int64_of_nat"]
-def Int64.ofNat (n : @& Nat) : Int64 := ⟨⟨BitVec.ofNat 64 n⟩⟩
-abbrev Int.toInt64 := Int64.ofInt
-abbrev Nat.toInt64 := Int64.ofNat
-@[extern "lean_int64_to_int_sint"]
-def Int64.toInt (i : Int64) : Int := i.toBitVec.toInt
-/--
-This function has the same behavior as `Int.toNat` for negative numbers.
-If you want to obtain the 2's complement representation use `toBitVec`.
--/
-@[inline] def Int64.toNat (i : Int64) : Nat := i.toInt.toNat
-@[extern "lean_int64_to_int8"]
-def Int64.toInt8 (a : Int64) : Int8 := ⟨⟨a.toBitVec.signExtend 8⟩⟩
-@[extern "lean_int64_to_int16"]
-def Int64.toInt16 (a : Int64) : Int16 := ⟨⟨a.toBitVec.signExtend 16⟩⟩
-@[extern "lean_int64_to_int32"]
-def Int64.toInt32 (a : Int64) : Int32 := ⟨⟨a.toBitVec.signExtend 32⟩⟩
-@[extern "lean_int8_to_int64"]
-def Int8.toInt64 (a : Int8) : Int64 := ⟨⟨a.toBitVec.signExtend 64⟩⟩
-@[extern "lean_int16_to_int64"]
-def Int16.toInt64 (a : Int16) : Int64 := ⟨⟨a.toBitVec.signExtend 64⟩⟩
-@[extern "lean_int32_to_int64"]
-def Int32.toInt64 (a : Int32) : Int64 := ⟨⟨a.toBitVec.signExtend 64⟩⟩
-@[extern "lean_int64_neg"]
-def Int64.neg (i : Int64) : Int64 := ⟨⟨-i.toBitVec⟩⟩
-
-instance : ToString Int64 where
-  toString i := toString i.toInt
-
-instance : OfNat Int64 n := ⟨Int64.ofNat n⟩
-instance : Neg Int64 where
-  neg := Int64.neg
-
-@[extern "lean_int64_add"]
-def Int64.add (a b : Int64) : Int64 := ⟨⟨a.toBitVec + b.toBitVec⟩⟩
-@[extern "lean_int64_sub"]
-def Int64.sub (a b : Int64) : Int64 := ⟨⟨a.toBitVec - b.toBitVec⟩⟩
-@[extern "lean_int64_mul"]
-def Int64.mul (a b : Int64) : Int64 := ⟨⟨a.toBitVec * b.toBitVec⟩⟩
-@[extern "lean_int64_div"]
-def Int64.div (a b : Int64) : Int64 := ⟨⟨BitVec.sdiv a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int64_mod"]
-def Int64.mod (a b : Int64) : Int64 := ⟨⟨BitVec.srem a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_int64_land"]
-def Int64.land (a b : Int64) : Int64 := ⟨⟨a.toBitVec &&& b.toBitVec⟩⟩
-@[extern "lean_int64_lor"]
-def Int64.lor (a b : Int64) : Int64 := ⟨⟨a.toBitVec ||| b.toBitVec⟩⟩
-@[extern "lean_int64_xor"]
-def Int64.xor (a b : Int64) : Int64 := ⟨⟨a.toBitVec ^^^ b.toBitVec⟩⟩
-@[extern "lean_int64_shift_left"]
-def Int64.shiftLeft (a b : Int64) : Int64 := ⟨⟨a.toBitVec <<< (b.toBitVec.smod 64)⟩⟩
-@[extern "lean_int64_shift_right"]
-def Int64.shiftRight (a b : Int64) : Int64 := ⟨⟨BitVec.sshiftRight' a.toBitVec (b.toBitVec.smod 64)⟩⟩
-@[extern "lean_int64_complement"]
-def Int64.complement (a : Int64) : Int64 := ⟨⟨~~~a.toBitVec⟩⟩
-
-@[extern "lean_int64_dec_eq"]
-def Int64.decEq (a b : Int64) : Decidable (a = b) :=
-  match a, b with
-  | ⟨n⟩, ⟨m⟩ =>
-    if h : n = m then
-      isTrue <| h ▸ rfl
-    else
-      isFalse (fun h' => Int64.noConfusion h' (fun h' => absurd h' h))
-
-def Int64.lt (a b : Int64) : Prop := a.toBitVec.slt b.toBitVec
-def Int64.le (a b : Int64) : Prop := a.toBitVec.sle b.toBitVec
-
-instance : Inhabited Int64 where
-  default := 0
-
-instance : Add Int64         := ⟨Int64.add⟩
-instance : Sub Int64         := ⟨Int64.sub⟩
-instance : Mul Int64         := ⟨Int64.mul⟩
-instance : Mod Int64         := ⟨Int64.mod⟩
-instance : Div Int64         := ⟨Int64.div⟩
-instance : LT Int64          := ⟨Int64.lt⟩
-instance : LE Int64          := ⟨Int64.le⟩
-instance : Complement Int64  := ⟨Int64.complement⟩
-instance : AndOp Int64       := ⟨Int64.land⟩
-instance : OrOp Int64        := ⟨Int64.lor⟩
-instance : Xor Int64         := ⟨Int64.xor⟩
-instance : ShiftLeft Int64   := ⟨Int64.shiftLeft⟩
-instance : ShiftRight Int64  := ⟨Int64.shiftRight⟩
-instance : DecidableEq Int64 := Int64.decEq
-
-@[extern "lean_int64_dec_lt"]
-def Int64.decLt (a b : Int64) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec.slt b.toBitVec))
-
-@[extern "lean_int64_dec_le"]
-def Int64.decLe (a b : Int64) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec.sle b.toBitVec))
-
-instance (a b : Int64) : Decidable (a < b) := Int64.decLt a b
-instance (a b : Int64) : Decidable (a ≤ b) := Int64.decLe a b
-instance : Max Int64 := maxOfLe
-instance : Min Int64 := minOfLe
-
-/-- The size of type `ISize`, that is, `2^System.Platform.numBits`. -/
-abbrev ISize.size : Nat := 2^System.Platform.numBits
-
-/--
-Obtain the `BitVec` that contains the 2's complement representation of the `ISize`.
--/
-@[inline] def ISize.toBitVec (x : ISize) : BitVec System.Platform.numBits := x.toUSize.toBitVec
-
-@[extern "lean_isize_of_int"]
-def ISize.ofInt (i : @& Int) : ISize := ⟨⟨BitVec.ofInt System.Platform.numBits i⟩⟩
-@[extern "lean_isize_of_nat"]
-def ISize.ofNat (n : @& Nat) : ISize := ⟨⟨BitVec.ofNat System.Platform.numBits n⟩⟩
-abbrev Int.toISize := ISize.ofInt
-abbrev Nat.toISize := ISize.ofNat
-@[extern "lean_isize_to_int"]
-def ISize.toInt (i : ISize) : Int := i.toBitVec.toInt
-/--
-This function has the same behavior as `Int.toNat` for negative numbers.
-If you want to obtain the 2's complement representation use `toBitVec`.
--/
-@[inline] def ISize.toNat (i : ISize) : Nat := i.toInt.toNat
-@[extern "lean_isize_to_int32"]
-def ISize.toInt32 (a : ISize) : Int32 := ⟨⟨a.toBitVec.signExtend 32⟩⟩
-/--
-Upcast `ISize` to `Int64`. This function is losless as `ISize` is either `Int32` or `Int64`.
--/
-@[extern "lean_isize_to_int64"]
-def ISize.toInt64 (a : ISize) : Int64 := ⟨⟨a.toBitVec.signExtend 64⟩⟩
-/--
-Upcast `Int32` to `ISize`. This function is losless as `ISize` is either `Int32` or `Int64`.
--/
-@[extern "lean_int32_to_isize"]
-def Int32.toISize (a : Int32) : ISize := ⟨⟨a.toBitVec.signExtend System.Platform.numBits⟩⟩
-@[extern "lean_int64_to_isize"]
-def Int64.toISize (a : Int64) : ISize := ⟨⟨a.toBitVec.signExtend System.Platform.numBits⟩⟩
-@[extern "lean_isize_neg"]
-def ISize.neg (i : ISize) : ISize := ⟨⟨-i.toBitVec⟩⟩
-
-instance : ToString ISize where
-  toString i := toString i.toInt
-
-instance : OfNat ISize n := ⟨ISize.ofNat n⟩
-instance : Neg ISize where
-  neg := ISize.neg
-
-@[extern "lean_isize_add"]
-def ISize.add (a b : ISize) : ISize := ⟨⟨a.toBitVec + b.toBitVec⟩⟩
-@[extern "lean_isize_sub"]
-def ISize.sub (a b : ISize) : ISize := ⟨⟨a.toBitVec - b.toBitVec⟩⟩
-@[extern "lean_isize_mul"]
-def ISize.mul (a b : ISize) : ISize := ⟨⟨a.toBitVec * b.toBitVec⟩⟩
-@[extern "lean_isize_div"]
-def ISize.div (a b : ISize) : ISize := ⟨⟨BitVec.sdiv a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_isize_mod"]
-def ISize.mod (a b : ISize) : ISize := ⟨⟨BitVec.srem a.toBitVec b.toBitVec⟩⟩
-@[extern "lean_isize_land"]
-def ISize.land (a b : ISize) : ISize := ⟨⟨a.toBitVec &&& b.toBitVec⟩⟩
-@[extern "lean_isize_lor"]
-def ISize.lor (a b : ISize) : ISize := ⟨⟨a.toBitVec ||| b.toBitVec⟩⟩
-@[extern "lean_isize_xor"]
-def ISize.xor (a b : ISize) : ISize := ⟨⟨a.toBitVec ^^^ b.toBitVec⟩⟩
-@[extern "lean_isize_shift_left"]
-def ISize.shiftLeft (a b : ISize) : ISize := ⟨⟨a.toBitVec <<< (b.toBitVec.smod System.Platform.numBits)⟩⟩
-@[extern "lean_isize_shift_right"]
-def ISize.shiftRight (a b : ISize) : ISize := ⟨⟨BitVec.sshiftRight' a.toBitVec (b.toBitVec.smod System.Platform.numBits)⟩⟩
-@[extern "lean_isize_complement"]
-def ISize.complement (a : ISize) : ISize := ⟨⟨~~~a.toBitVec⟩⟩
-
-@[extern "lean_isize_dec_eq"]
-def ISize.decEq (a b : ISize) : Decidable (a = b) :=
-  match a, b with
-  | ⟨n⟩, ⟨m⟩ =>
-    if h : n = m then
-      isTrue <| h ▸ rfl
-    else
-      isFalse (fun h' => ISize.noConfusion h' (fun h' => absurd h' h))
-
-def ISize.lt (a b : ISize) : Prop := a.toBitVec.slt b.toBitVec
-def ISize.le (a b : ISize) : Prop := a.toBitVec.sle b.toBitVec
-
-instance : Inhabited ISize where
-  default := 0
-
-instance : Add ISize         := ⟨ISize.add⟩
-instance : Sub ISize         := ⟨ISize.sub⟩
-instance : Mul ISize         := ⟨ISize.mul⟩
-instance : Mod ISize         := ⟨ISize.mod⟩
-instance : Div ISize         := ⟨ISize.div⟩
-instance : LT ISize          := ⟨ISize.lt⟩
-instance : LE ISize          := ⟨ISize.le⟩
-instance : Complement ISize  := ⟨ISize.complement⟩
-instance : AndOp ISize       := ⟨ISize.land⟩
-instance : OrOp ISize        := ⟨ISize.lor⟩
-instance : Xor ISize         := ⟨ISize.xor⟩
-instance : ShiftLeft ISize   := ⟨ISize.shiftLeft⟩
-instance : ShiftRight ISize  := ⟨ISize.shiftRight⟩
-instance : DecidableEq ISize := ISize.decEq
-
-@[extern "lean_isize_dec_lt"]
-def ISize.decLt (a b : ISize) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec.slt b.toBitVec))
-
-@[extern "lean_isize_dec_le"]
-def ISize.decLe (a b : ISize) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec.sle b.toBitVec))
-
-instance (a b : ISize) : Decidable (a < b) := ISize.decLt a b
-instance (a b : ISize) : Decidable (a ≤ b) := ISize.decLe a b
-instance : Max ISize := maxOfLe
-instance : Min ISize := minOfLe

src/Init/Data/Stream.lean

@@ -94,7 +94,7 @@ instance : Stream (Subarray α) α where
   next? s :=
     if h : s.start < s.stop then
       have : s.start + 1 ≤ s.stop := Nat.succ_le_of_lt h
-      some (s.array[s.start]'(Nat.lt_of_lt_of_le h s.stop_le_array_size),
+      some (s.array.get ⟨s.start, Nat.lt_of_lt_of_le h s.stop_le_array_size⟩,
         { s with start := s.start + 1, start_le_stop := this })
     else
       none

src/Init/Data/String/Basic.lean

@@ -6,6 +6,7 @@ Author: Leonardo de Moura, Mario Carneiro
 prelude
 import Init.Data.List.Basic
 import Init.Data.Char.Basic
+import Init.Data.Option.Basic
 
 universe u
 
@@ -1147,23 +1148,23 @@ namespace String
 /--
 If `pre` is a prefix of `s`, i.e. `s = pre ++ t`, returns the remainder `t`.
 -/
-def dropPrefix? (s : String) (pre : String) : Option Substring :=
-  s.toSubstring.dropPrefix? pre.toSubstring
+def dropPrefix? (s : String) (pre : Substring) : Option Substring :=
+  s.toSubstring.dropPrefix? pre
 
 /--
 If `suff` is a suffix of `s`, i.e. `s = t ++ suff`, returns the remainder `t`.
 -/
-def dropSuffix? (s : String) (suff : String) : Option Substring :=
-  s.toSubstring.dropSuffix? suff.toSubstring
+def dropSuffix? (s : String) (suff : Substring) : Option Substring :=
+  s.toSubstring.dropSuffix? suff
 
 /-- `s.stripPrefix pre` will remove `pre` from the beginning of `s` if it occurs there,
 or otherwise return `s`. -/
-def stripPrefix (s : String) (pre : String) : String :=
+def stripPrefix (s : String) (pre : Substring) : String :=
   s.dropPrefix? pre |>.map Substring.toString |>.getD s
 
 /-- `s.stripSuffix suff` will remove `suff` from the end of `s` if it occurs there,
 or otherwise return `s`. -/
-def stripSuffix (s : String) (suff : String) : String :=
+def stripSuffix (s : String) (suff : Substring) : String :=
   s.dropSuffix? suff |>.map Substring.toString |>.getD s
 
 end String

src/Init/Data/String/Extra.lean

@@ -134,7 +134,7 @@ def toUTF8 (a : @& String) : ByteArray :=
 /-- Accesses a byte in the UTF-8 encoding of the `String`. O(1) -/
 @[extern "lean_string_get_byte_fast"]
 def getUtf8Byte (s : @& String) (n : Nat) (h : n < s.utf8ByteSize) : UInt8 :=
-  (toUTF8 s)[n]'(size_toUTF8 _ ▸ h)
+  (toUTF8 s).get ⟨n, size_toUTF8 _ ▸ h⟩
 
 theorem Iterator.sizeOf_next_lt_of_hasNext (i : String.Iterator) (h : i.hasNext) : sizeOf i.next < sizeOf i := by
   cases i; rename_i s pos; simp [Iterator.next, Iterator.sizeOf_eq]; simp [Iterator.hasNext] at h

src/Init/Data/Sum.lean

@@ -4,5 +4,21 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Mario Carneiro, Yury G. Kudryashov
 -/
 prelude
-import Init.Data.Sum.Basic
-import Init.Data.Sum.Lemmas
+import Init.Core
+
+namespace Sum
+
+deriving instance DecidableEq for Sum
+deriving instance BEq for Sum
+
+/-- Check if a sum is `inl` and if so, retrieve its contents. -/
+def getLeft? : α ⊕ β → Option α
+  | inl a => some a
+  | inr _ => none
+
+/-- Check if a sum is `inr` and if so, retrieve its contents. -/
+def getRight? : α ⊕ β → Option β
+  | inr b => some b
+  | inl _ => none
+
+end Sum

src/Init/Data/Sum/Basic.lean

@@ -1,178 +0,0 @@
-/-
-Copyright (c) 2017 Mario Carneiro. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Mario Carneiro, Yury G. Kudryashov
--/
-prelude
-import Init.PropLemmas
-
-/-!
-# Disjoint union of types
-
-This file defines basic operations on the the sum type `α ⊕ β`.
-
-`α ⊕ β` is the type made of a copy of `α` and a copy of `β`. It is also called *disjoint union*.
-
-## Main declarations
-
-* `Sum.isLeft`: Returns whether `x : α ⊕ β` comes from the left component or not.
-* `Sum.isRight`: Returns whether `x : α ⊕ β` comes from the right component or not.
-* `Sum.getLeft`: Retrieves the left content of a `x : α ⊕ β` that is known to come from the left.
-* `Sum.getRight`: Retrieves the right content of `x : α ⊕ β` that is known to come from the right.
-* `Sum.getLeft?`: Retrieves the left content of `x : α ⊕ β` as an option type or returns `none`
-  if it's coming from the right.
-* `Sum.getRight?`: Retrieves the right content of `x : α ⊕ β` as an option type or returns `none`
-  if it's coming from the left.
-* `Sum.map`: Maps `α ⊕ β` to `γ ⊕ δ` component-wise.
-* `Sum.elim`: Nondependent eliminator/induction principle for `α ⊕ β`.
-* `Sum.swap`: Maps `α ⊕ β` to `β ⊕ α` by swapping components.
-* `Sum.LiftRel`: The disjoint union of two relations.
-* `Sum.Lex`: Lexicographic order on `α ⊕ β` induced by a relation on `α` and a relation on `β`.
-
-## Further material
-
-See `Batteries.Data.Sum.Lemmas` for theorems about these definitions.
-
-## Notes
-
-The definition of `Sum` takes values in `Type _`. This effectively forbids `Prop`- valued sum types.
-To this effect, we have `PSum`, which takes value in `Sort _` and carries a more complicated
-universe signature in consequence. The `Prop` version is `Or`.
--/
-
-namespace Sum
-
-deriving instance DecidableEq for Sum
-deriving instance BEq for Sum
-
-section get
-
-/-- Check if a sum is `inl`. -/
-def isLeft : α ⊕ β → Bool
-  | inl _ => true
-  | inr _ => false
-
-/-- Check if a sum is `inr`. -/
-def isRight : α ⊕ β → Bool
-  | inl _ => false
-  | inr _ => true
-
-/-- Retrieve the contents from a sum known to be `inl`.-/
-def getLeft : (ab : α ⊕ β) → ab.isLeft → α
-  | inl a, _ => a
-
-/-- Retrieve the contents from a sum known to be `inr`.-/
-def getRight : (ab : α ⊕ β) → ab.isRight → β
-  | inr b, _ => b
-
-/-- Check if a sum is `inl` and if so, retrieve its contents. -/
-def getLeft? : α ⊕ β → Option α
-  | inl a => some a
-  | inr _ => none
-
-/-- Check if a sum is `inr` and if so, retrieve its contents. -/
-def getRight? : α ⊕ β → Option β
-  | inr b => some b
-  | inl _ => none
-
-@[simp] theorem isLeft_inl : (inl x : α ⊕ β).isLeft = true := rfl
-@[simp] theorem isLeft_inr : (inr x : α ⊕ β).isLeft = false := rfl
-@[simp] theorem isRight_inl : (inl x : α ⊕ β).isRight = false := rfl
-@[simp] theorem isRight_inr : (inr x : α ⊕ β).isRight = true := rfl
-
-@[simp] theorem getLeft_inl (h : (inl x : α ⊕ β).isLeft) : (inl x).getLeft h = x := rfl
-@[simp] theorem getRight_inr (h : (inr x : α ⊕ β).isRight) : (inr x).getRight h = x := rfl
-
-@[simp] theorem getLeft?_inl : (inl x : α ⊕ β).getLeft? = some x := rfl
-@[simp] theorem getLeft?_inr : (inr x : α ⊕ β).getLeft? = none := rfl
-@[simp] theorem getRight?_inl : (inl x : α ⊕ β).getRight? = none := rfl
-@[simp] theorem getRight?_inr : (inr x : α ⊕ β).getRight? = some x := rfl
-
-end get
-
-/-- Define a function on `α ⊕ β` by giving separate definitions on `α` and `β`. -/
-protected def elim {α β γ} (f : α → γ) (g : β → γ) : α ⊕ β → γ :=
-  fun x => Sum.casesOn x f g
-
-@[simp] theorem elim_inl (f : α → γ) (g : β → γ) (x : α) :
-    Sum.elim f g (inl x) = f x := rfl
-
-@[simp] theorem elim_inr (f : α → γ) (g : β → γ) (x : β) :
-    Sum.elim f g (inr x) = g x := rfl
-
-/-- Map `α ⊕ β` to `α' ⊕ β'` sending `α` to `α'` and `β` to `β'`. -/
-protected def map (f : α → α') (g : β → β') : α ⊕ β → α' ⊕ β' :=
-  Sum.elim (inl ∘ f) (inr ∘ g)
-
-@[simp] theorem map_inl (f : α → α') (g : β → β') (x : α) : (inl x).map f g = inl (f x) := rfl
-
-@[simp] theorem map_inr (f : α → α') (g : β → β') (x : β) : (inr x).map f g = inr (g x) := rfl
-
-/-- Swap the factors of a sum type -/
-def swap : α ⊕ β → β ⊕ α := Sum.elim inr inl
-
-@[simp] theorem swap_inl : swap (inl x : α ⊕ β) = inr x := rfl
-
-@[simp] theorem swap_inr : swap (inr x : α ⊕ β) = inl x := rfl
-
-section LiftRel
-
-/-- Lifts pointwise two relations between `α` and `γ` and between `β` and `δ` to a relation between
-`α ⊕ β` and `γ ⊕ δ`. -/
-inductive LiftRel (r : α → γ → Prop) (s : β → δ → Prop) : α ⊕ β → γ ⊕ δ → Prop
-  /-- `inl a` and `inl c` are related via `LiftRel r s` if `a` and `c` are related via `r`. -/
-  | protected inl {a c} : r a c → LiftRel r s (inl a) (inl c)
-  /-- `inr b` and `inr d` are related via `LiftRel r s` if `b` and `d` are related via `s`. -/
-  | protected inr {b d} : s b d → LiftRel r s (inr b) (inr d)
-
-@[simp] theorem liftRel_inl_inl : LiftRel r s (inl a) (inl c) ↔ r a c :=
-  ⟨fun h => by cases h; assumption, LiftRel.inl⟩
-
-@[simp] theorem not_liftRel_inl_inr : ¬LiftRel r s (inl a) (inr d) := nofun
-
-@[simp] theorem not_liftRel_inr_inl : ¬LiftRel r s (inr b) (inl c) := nofun
-
-@[simp] theorem liftRel_inr_inr : LiftRel r s (inr b) (inr d) ↔ s b d :=
-  ⟨fun h => by cases h; assumption, LiftRel.inr⟩
-
-instance {r : α → γ → Prop} {s : β → δ → Prop}
-    [∀ a c, Decidable (r a c)] [∀ b d, Decidable (s b d)] :
-    ∀ (ab : α ⊕ β) (cd : γ ⊕ δ), Decidable (LiftRel r s ab cd)
-  | inl _, inl _ => decidable_of_iff' _ liftRel_inl_inl
-  | inl _, inr _ => Decidable.isFalse not_liftRel_inl_inr
-  | inr _, inl _ => Decidable.isFalse not_liftRel_inr_inl
-  | inr _, inr _ => decidable_of_iff' _ liftRel_inr_inr
-
-end LiftRel
-
-section Lex
-
-/-- Lexicographic order for sum. Sort all the `inl a` before the `inr b`, otherwise use the
-respective order on `α` or `β`. -/
-inductive Lex (r : α → α → Prop) (s : β → β → Prop) : α ⊕ β → α ⊕ β → Prop
-  /-- `inl a₁` and `inl a₂` are related via `Lex r s` if `a₁` and `a₂` are related via `r`. -/
-  | protected inl {a₁ a₂} (h : r a₁ a₂) : Lex r s (inl a₁) (inl a₂)
-  /-- `inr b₁` and `inr b₂` are related via `Lex r s` if `b₁` and `b₂` are related via `s`. -/
-  | protected inr {b₁ b₂} (h : s b₁ b₂) : Lex r s (inr b₁) (inr b₂)
-  /-- `inl a` and `inr b` are always related via `Lex r s`. -/
-  | sep (a b) : Lex r s (inl a) (inr b)
-
-attribute [simp] Lex.sep
-
-@[simp] theorem lex_inl_inl : Lex r s (inl a₁) (inl a₂) ↔ r a₁ a₂ :=
-  ⟨fun h => by cases h; assumption, Lex.inl⟩
-
-@[simp] theorem lex_inr_inr : Lex r s (inr b₁) (inr b₂) ↔ s b₁ b₂ :=
-  ⟨fun h => by cases h; assumption, Lex.inr⟩
-
-@[simp] theorem lex_inr_inl : ¬Lex r s (inr b) (inl a) := nofun
-
-instance instDecidableRelSumLex [DecidableRel r] [DecidableRel s] : DecidableRel (Lex r s)
-  | inl _, inl _ => decidable_of_iff' _ lex_inl_inl
-  | inl _, inr _ => Decidable.isTrue (Lex.sep _ _)
-  | inr _, inl _ => Decidable.isFalse lex_inr_inl
-  | inr _, inr _ => decidable_of_iff' _ lex_inr_inr
-
-end Lex
-
-end Sum

src/Init/Data/Sum/Lemmas.lean

@@ -1,251 +0,0 @@
-/-
-Copyright (c) 2017 Mario Carneiro. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Mario Carneiro, Yury G. Kudryashov
--/
-prelude
-import Init.Data.Sum.Basic
-import Init.Ext
-
-/-!
-# Disjoint union of types
-
-Theorems about the definitions introduced in `Init.Data.Sum.Basic`.
--/
-
-open Function
-
-namespace Sum
-
-protected theorem «forall» {p : α ⊕ β → Prop} :
-    (∀ x, p x) ↔ (∀ a, p (inl a)) ∧ ∀ b, p (inr b) :=
-  ⟨fun h => ⟨fun _ => h _, fun _ => h _⟩, fun ⟨h₁, h₂⟩ => Sum.rec h₁ h₂⟩
-
-protected theorem «exists» {p : α ⊕ β → Prop} :
-    (∃ x, p x) ↔ (∃ a, p (inl a)) ∨ ∃ b, p (inr b) :=
-  ⟨ fun
-    | ⟨inl a, h⟩ => Or.inl ⟨a, h⟩
-    | ⟨inr b, h⟩ => Or.inr ⟨b, h⟩,
-    fun
-    | Or.inl ⟨a, h⟩ => ⟨inl a, h⟩
-    | Or.inr ⟨b, h⟩ => ⟨inr b, h⟩⟩
-
-theorem forall_sum {γ : α ⊕ β → Sort _} (p : (∀ ab, γ ab) → Prop) :
-    (∀ fab, p fab) ↔ (∀ fa fb, p (Sum.rec fa fb)) := by
-  refine ⟨fun h fa fb => h _, fun h fab => ?_⟩
-  have h1 : fab = Sum.rec (fun a => fab (Sum.inl a)) (fun b => fab (Sum.inr b)) := by
-    apply funext
-    rintro (_ | _) <;> rfl
-  rw [h1]; exact h _ _
-
-section get
-
-@[simp] theorem inl_getLeft : ∀ (x : α ⊕ β) (h : x.isLeft), inl (x.getLeft h) = x
-  | inl _, _ => rfl
-@[simp] theorem inr_getRight : ∀ (x : α ⊕ β) (h : x.isRight), inr (x.getRight h) = x
-  | inr _, _ => rfl
-
-@[simp] theorem getLeft?_eq_none_iff {x : α ⊕ β} : x.getLeft? = none ↔ x.isRight := by
-  cases x <;> simp only [getLeft?, isRight, eq_self_iff_true, reduceCtorEq]
-
-@[simp] theorem getRight?_eq_none_iff {x : α ⊕ β} : x.getRight? = none ↔ x.isLeft := by
-  cases x <;> simp only [getRight?, isLeft, eq_self_iff_true, reduceCtorEq]
-
-theorem eq_left_getLeft_of_isLeft : ∀ {x : α ⊕ β} (h : x.isLeft), x = inl (x.getLeft h)
-  | inl _, _ => rfl
-
-@[simp] theorem getLeft_eq_iff (h : x.isLeft) : x.getLeft h = a ↔ x = inl a := by
-  cases x <;> simp at h ⊢
-
-theorem eq_right_getRight_of_isRight : ∀ {x : α ⊕ β} (h : x.isRight), x = inr (x.getRight h)
-  | inr _, _ => rfl
-
-@[simp] theorem getRight_eq_iff (h : x.isRight) : x.getRight h = b ↔ x = inr b := by
-  cases x <;> simp at h ⊢
-
-@[simp] theorem getLeft?_eq_some_iff : x.getLeft? = some a ↔ x = inl a := by
-  cases x <;> simp only [getLeft?, Option.some.injEq, inl.injEq, reduceCtorEq]
-
-@[simp] theorem getRight?_eq_some_iff : x.getRight? = some b ↔ x = inr b := by
-  cases x <;> simp only [getRight?, Option.some.injEq, inr.injEq, reduceCtorEq]
-
-@[simp] theorem bnot_isLeft (x : α ⊕ β) : !x.isLeft = x.isRight := by cases x <;> rfl
-
-@[simp] theorem isLeft_eq_false {x : α ⊕ β} : x.isLeft = false ↔ x.isRight := by cases x <;> simp
-
-theorem not_isLeft {x : α ⊕ β} : ¬x.isLeft ↔ x.isRight := by simp
-
-@[simp] theorem bnot_isRight (x : α ⊕ β) : !x.isRight = x.isLeft := by cases x <;> rfl
-
-@[simp] theorem isRight_eq_false {x : α ⊕ β} : x.isRight = false ↔ x.isLeft := by cases x <;> simp
-
-theorem not_isRight {x : α ⊕ β} : ¬x.isRight ↔ x.isLeft := by simp
-
-theorem isLeft_iff : x.isLeft ↔ ∃ y, x = Sum.inl y := by cases x <;> simp
-
-theorem isRight_iff : x.isRight ↔ ∃ y, x = Sum.inr y := by cases x <;> simp
-
-end get
-
-theorem inl.inj_iff : (inl a : α ⊕ β) = inl b ↔ a = b := ⟨inl.inj, congrArg _⟩
-
-theorem inr.inj_iff : (inr a : α ⊕ β) = inr b ↔ a = b := ⟨inr.inj, congrArg _⟩
-
-theorem inl_ne_inr : inl a ≠ inr b := nofun
-
-theorem inr_ne_inl : inr b ≠ inl a := nofun
-
-/-! ### `Sum.elim` -/
-
-@[simp] theorem elim_comp_inl (f : α → γ) (g : β → γ) : Sum.elim f g ∘ inl = f :=
-  rfl
-
-@[simp] theorem elim_comp_inr (f : α → γ) (g : β → γ) : Sum.elim f g ∘ inr = g :=
-  rfl
-
-@[simp] theorem elim_inl_inr : @Sum.elim α β _ inl inr = id :=
-  funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
-
-theorem comp_elim (f : γ → δ) (g : α → γ) (h : β → γ) :
-    f ∘ Sum.elim g h = Sum.elim (f ∘ g) (f ∘ h) :=
-  funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
-
-@[simp] theorem elim_comp_inl_inr (f : α ⊕ β → γ) :
-    Sum.elim (f ∘ inl) (f ∘ inr) = f :=
-  funext fun x => Sum.casesOn x (fun _ => rfl) fun _ => rfl
-
-theorem elim_eq_iff {u u' : α → γ} {v v' : β → γ} :
-    Sum.elim u v = Sum.elim u' v' ↔ u = u' ∧ v = v' := by
-  simp [funext_iff, Sum.forall]
-
-/-! ### `Sum.map` -/
-
-@[simp] theorem map_map (f' : α' → α'') (g' : β' → β'') (f : α → α') (g : β → β') :
-    ∀ x : Sum α β, (x.map f g).map f' g' = x.map (f' ∘ f) (g' ∘ g)
-  | inl _ => rfl
-  | inr _ => rfl
-
-@[simp] theorem map_comp_map (f' : α' → α'') (g' : β' → β'') (f : α → α') (g : β → β') :
-    Sum.map f' g' ∘ Sum.map f g = Sum.map (f' ∘ f) (g' ∘ g) :=
-  funext <| map_map f' g' f g
-
-@[simp] theorem map_id_id : Sum.map (@id α) (@id β) = id :=
-  funext fun x => Sum.recOn x (fun _ => rfl) fun _ => rfl
-
-theorem elim_map {f₁ : α → β} {f₂ : β → ε} {g₁ : γ → δ} {g₂ : δ → ε} {x} :
-    Sum.elim f₂ g₂ (Sum.map f₁ g₁ x) = Sum.elim (f₂ ∘ f₁) (g₂ ∘ g₁) x := by
-  cases x <;> rfl
-
-theorem elim_comp_map {f₁ : α → β} {f₂ : β → ε} {g₁ : γ → δ} {g₂ : δ → ε} :
-    Sum.elim f₂ g₂ ∘ Sum.map f₁ g₁ = Sum.elim (f₂ ∘ f₁) (g₂ ∘ g₁) :=
-  funext fun _ => elim_map
-
-@[simp] theorem isLeft_map (f : α → β) (g : γ → δ) (x : α ⊕ γ) :
-    isLeft (x.map f g) = isLeft x := by
-  cases x <;> rfl
-
-@[simp] theorem isRight_map (f : α → β) (g : γ → δ) (x : α ⊕ γ) :
-    isRight (x.map f g) = isRight x := by
-  cases x <;> rfl
-
-@[simp] theorem getLeft?_map (f : α → β) (g : γ → δ) (x : α ⊕ γ) :
-    (x.map f g).getLeft? = x.getLeft?.map f := by
-  cases x <;> rfl
-
-@[simp] theorem getRight?_map (f : α → β) (g : γ → δ) (x : α ⊕ γ) :
-    (x.map f g).getRight? = x.getRight?.map g := by cases x <;> rfl
-
-/-! ### `Sum.swap` -/
-
-@[simp] theorem swap_swap (x : α ⊕ β) : swap (swap x) = x := by cases x <;> rfl
-
-@[simp] theorem swap_swap_eq : swap ∘ swap = @id (α ⊕ β) := funext <| swap_swap
-
-@[simp] theorem isLeft_swap (x : α ⊕ β) : x.swap.isLeft = x.isRight := by cases x <;> rfl
-
-@[simp] theorem isRight_swap (x : α ⊕ β) : x.swap.isRight = x.isLeft := by cases x <;> rfl
-
-@[simp] theorem getLeft?_swap (x : α ⊕ β) : x.swap.getLeft? = x.getRight? := by cases x <;> rfl
-
-@[simp] theorem getRight?_swap (x : α ⊕ β) : x.swap.getRight? = x.getLeft? := by cases x <;> rfl
-
-section LiftRel
-
-theorem LiftRel.mono (hr : ∀ a b, r₁ a b → r₂ a b) (hs : ∀ a b, s₁ a b → s₂ a b)
-  (h : LiftRel r₁ s₁ x y) : LiftRel r₂ s₂ x y := by
-  cases h
-  · exact LiftRel.inl (hr _ _ ‹_›)
-  · exact LiftRel.inr (hs _ _ ‹_›)
-
-theorem LiftRel.mono_left (hr : ∀ a b, r₁ a b → r₂ a b) (h : LiftRel r₁ s x y) :
-    LiftRel r₂ s x y :=
-  (h.mono hr) fun _ _ => id
-
-theorem LiftRel.mono_right (hs : ∀ a b, s₁ a b → s₂ a b) (h : LiftRel r s₁ x y) :
-    LiftRel r s₂ x y :=
-  h.mono (fun _ _ => id) hs
-
-protected theorem LiftRel.swap (h : LiftRel r s x y) : LiftRel s r x.swap y.swap := by
-  cases h
-  · exact LiftRel.inr ‹_›
-  · exact LiftRel.inl ‹_›
-
-@[simp] theorem liftRel_swap_iff : LiftRel s r x.swap y.swap ↔ LiftRel r s x y :=
-  ⟨fun h => by rw [← swap_swap x, ← swap_swap y]; exact h.swap, LiftRel.swap⟩
-
-end LiftRel
-
-section Lex
-
-protected theorem LiftRel.lex {a b : α ⊕ β} (h : LiftRel r s a b) : Lex r s a b := by
-  cases h
-  · exact Lex.inl ‹_›
-  · exact Lex.inr ‹_›
-
-theorem liftRel_subrelation_lex : Subrelation (LiftRel r s) (Lex r s) := LiftRel.lex
-
-theorem Lex.mono (hr : ∀ a b, r₁ a b → r₂ a b) (hs : ∀ a b, s₁ a b → s₂ a b) (h : Lex r₁ s₁ x y) :
-    Lex r₂ s₂ x y := by
-  cases h
-  · exact Lex.inl (hr _ _ ‹_›)
-  · exact Lex.inr (hs _ _ ‹_›)
-  · exact Lex.sep _ _
-
-theorem Lex.mono_left (hr : ∀ a b, r₁ a b → r₂ a b) (h : Lex r₁ s x y) : Lex r₂ s x y :=
-  (h.mono hr) fun _ _ => id
-
-theorem Lex.mono_right (hs : ∀ a b, s₁ a b → s₂ a b) (h : Lex r s₁ x y) : Lex r s₂ x y :=
-  h.mono (fun _ _ => id) hs
-
-theorem lex_acc_inl (aca : Acc r a) : Acc (Lex r s) (inl a) := by
-  induction aca with
-  | intro _ _ IH =>
-    constructor
-    intro y h
-    cases h with
-    | inl h' => exact IH _ h'
-
-theorem lex_acc_inr (aca : ∀ a, Acc (Lex r s) (inl a)) {b} (acb : Acc s b) :
-    Acc (Lex r s) (inr b) := by
-  induction acb with
-  | intro _ _ IH =>
-    constructor
-    intro y h
-    cases h with
-    | inr h' => exact IH _ h'
-    | sep => exact aca _
-
-theorem lex_wf (ha : WellFounded r) (hb : WellFounded s) : WellFounded (Lex r s) :=
-  have aca : ∀ a, Acc (Lex r s) (inl a) := fun a => lex_acc_inl (ha.apply a)
-  ⟨fun x => Sum.recOn x aca fun b => lex_acc_inr aca (hb.apply b)⟩
-
-end Lex
-
-theorem elim_const_const (c : γ) :
-    Sum.elim (const _ c : α → γ) (const _ c : β → γ) = const _ c := by
-  apply funext
-  rintro (_ | _) <;> rfl
-
-@[simp] theorem elim_lam_const_lam_const (c : γ) :
-    Sum.elim (fun _ : α => c) (fun _ : β => c) = fun _ => c :=
-  Sum.elim_const_const c

src/Init/Data/ToString/Basic.lean

@@ -4,9 +4,14 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 -/
 prelude
+import Init.Data.String.Basic
+import Init.Data.UInt.BasicAux
+import Init.Data.Nat.Div
 import Init.Data.Repr
-import Init.Data.Option.Basic
-
+import Init.Data.Int.Basic
+import Init.Data.Format.Basic
+import Init.Control.Id
+import Init.Control.Option
 open Sum Subtype Nat
 
 open Std

src/Init/Data/UInt/Basic.lean

@@ -19,8 +19,8 @@ def UInt8.mul (a b : UInt8) : UInt8 := ⟨a.toBitVec * b.toBitVec⟩
 def UInt8.div (a b : UInt8) : UInt8 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
 @[extern "lean_uint8_mod"]
 def UInt8.mod (a b : UInt8) : UInt8 := ⟨BitVec.umod a.toBitVec b.toBitVec⟩
-@[deprecated UInt8.mod (since := "2024-09-23")]
-def UInt8.modn (a : UInt8) (n : Nat) : UInt8 := ⟨Fin.modn a.val n⟩
+@[extern "lean_uint8_modn", deprecated UInt8.mod (since := "2024-09-23")]
+def UInt8.modn (a : UInt8) (n : @& Nat) : UInt8 := ⟨Fin.modn a.val n⟩
 @[extern "lean_uint8_land"]
 def UInt8.land (a b : UInt8) : UInt8 := ⟨a.toBitVec &&& b.toBitVec⟩
 @[extern "lean_uint8_lor"]
@@ -79,8 +79,8 @@ def UInt16.mul (a b : UInt16) : UInt16 := ⟨a.toBitVec * b.toBitVec⟩
 def UInt16.div (a b : UInt16) : UInt16 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
 @[extern "lean_uint16_mod"]
 def UInt16.mod (a b : UInt16) : UInt16 := ⟨BitVec.umod a.toBitVec b.toBitVec⟩
-@[deprecated UInt16.mod (since := "2024-09-23")]
-def UInt16.modn (a : UInt16) (n : Nat) : UInt16 := ⟨Fin.modn a.val n⟩
+@[extern "lean_uint16_modn", deprecated UInt16.mod (since := "2024-09-23")]
+def UInt16.modn (a : UInt16) (n : @& Nat) : UInt16 := ⟨Fin.modn a.val n⟩
 @[extern "lean_uint16_land"]
 def UInt16.land (a b : UInt16) : UInt16 := ⟨a.toBitVec &&& b.toBitVec⟩
 @[extern "lean_uint16_lor"]
@@ -141,8 +141,8 @@ def UInt32.mul (a b : UInt32) : UInt32 := ⟨a.toBitVec * b.toBitVec⟩
 def UInt32.div (a b : UInt32) : UInt32 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
 @[extern "lean_uint32_mod"]
 def UInt32.mod (a b : UInt32) : UInt32 := ⟨BitVec.umod a.toBitVec b.toBitVec⟩
-@[deprecated UInt32.mod (since := "2024-09-23")]
-def UInt32.modn (a : UInt32) (n : Nat) : UInt32 := ⟨Fin.modn a.val n⟩
+@[extern "lean_uint32_modn", deprecated UInt32.mod (since := "2024-09-23")]
+def UInt32.modn (a : UInt32) (n : @& Nat) : UInt32 := ⟨Fin.modn a.val n⟩
 @[extern "lean_uint32_land"]
 def UInt32.land (a b : UInt32) : UInt32 := ⟨a.toBitVec &&& b.toBitVec⟩
 @[extern "lean_uint32_lor"]
@@ -184,8 +184,8 @@ def UInt64.mul (a b : UInt64) : UInt64 := ⟨a.toBitVec * b.toBitVec⟩
 def UInt64.div (a b : UInt64) : UInt64 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
 @[extern "lean_uint64_mod"]
 def UInt64.mod (a b : UInt64) : UInt64 := ⟨BitVec.umod a.toBitVec b.toBitVec⟩
-@[deprecated UInt64.mod (since := "2024-09-23")]
-def UInt64.modn (a : UInt64) (n : Nat) : UInt64 := ⟨Fin.modn a.val n⟩
+@[extern "lean_uint64_modn", deprecated UInt64.mod (since := "2024-09-23")]
+def UInt64.modn (a : UInt64) (n : @& Nat) : UInt64 := ⟨Fin.modn a.val n⟩
 @[extern "lean_uint64_land"]
 def UInt64.land (a b : UInt64) : UInt64 := ⟨a.toBitVec &&& b.toBitVec⟩
 @[extern "lean_uint64_lor"]
@@ -243,8 +243,8 @@ def USize.mul (a b : USize) : USize := ⟨a.toBitVec * b.toBitVec⟩
 def USize.div (a b : USize) : USize := ⟨a.toBitVec / b.toBitVec⟩
 @[extern "lean_usize_mod"]
 def USize.mod (a b : USize) : USize := ⟨a.toBitVec % b.toBitVec⟩
-@[deprecated USize.mod (since := "2024-09-23")]
-def USize.modn (a : USize) (n : Nat) : USize := ⟨Fin.modn a.val n⟩
+@[extern "lean_usize_modn", deprecated USize.mod (since := "2024-09-23")]
+def USize.modn (a : USize) (n : @& Nat) : USize := ⟨Fin.modn a.val n⟩
 @[extern "lean_usize_land"]
 def USize.land (a b : USize) : USize := ⟨a.toBitVec &&& b.toBitVec⟩
 @[extern "lean_usize_lor"]