chore: rename List.bind and Array.concatMap to flatMap

fix

.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/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}",

.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:

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/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-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

@@ -10,7 +10,7 @@ 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'")
@@ -155,10 +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)
@@ -301,23 +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)
@@ -501,7 +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

@@ -35,4 +35,3 @@ import Init.Ext
 import Init.Omega
 import Init.MacroTrace
 import Init.Grind
-import Init.While

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/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
@@ -1384,7 +1385,6 @@ gen_injective_theorems% Except
 gen_injective_theorems% EStateM.Result
 gen_injective_theorems% Lean.Name
 gen_injective_theorems% Lean.Syntax
-gen_injective_theorems% BitVec
 
 theorem Nat.succ.inj {m n : Nat} : m.succ = n.succ → m = n :=
   fun x => Nat.noConfusion x id
@@ -1864,8 +1864,7 @@ section
 variable {α : Type u}
 variable (r : α → α → Prop)
 
-instance Quotient.decidableEq {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)]
-    : DecidableEq (Quotient s) :=
+instance {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)] : DecidableEq (Quotient s) :=
   fun (q₁ q₂ : Quotient s) =>
     Quotient.recOnSubsingleton₂ q₁ q₂
       fun a₁ a₂ =>
@@ -1936,6 +1935,15 @@ 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 -/
 
@@ -2111,14 +2119,4 @@ 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

@@ -16,4 +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

src/Init/Data/Array/Basic.lean

@@ -7,7 +7,7 @@ prelude
 import Init.WFTactics
 import Init.Data.Nat.Basic
 import Init.Data.Fin.Basic
-import Init.Data.UInt.BasicAux
+import Init.Data.UInt.Basic
 import Init.Data.Repr
 import Init.Data.ToString.Basic
 import Init.GetElem
@@ -25,8 +25,6 @@ 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 : Fin a.size) (v : α) : (set a i v).size = a.size :=
@@ -80,42 +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
@@ -235,11 +197,9 @@ 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
 
@@ -259,15 +219,12 @@ 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
@@ -304,21 +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
@@ -326,17 +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
@@ -371,7 +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
@@ -410,7 +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
@@ -441,25 +396,20 @@ 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)
 
-/-- 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] (as : Array α) (f : Nat → α → m β) : 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] (as : Array α) (f : α → m (Option β)) : m (Option β) := do
   for a in as do
@@ -565,13 +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} (as : Array α) (f : Nat → α → β) : 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)]`. -/
@@ -665,7 +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 :=
@@ -872,15 +817,9 @@ def split (as : Array α) (p : α → Bool) : Array α × Array α :=
 
 /-! ## 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/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

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 (as : Array α) (f : Nat → 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.mapIdx as f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((Array.mapIdx as f)[i]) :=
-  mapFinIdx_induction as (fun i a => f i a) motive h0 p hs
-
-theorem mapIdx_spec (as : Array α) (f : Nat → α → β)
-    (p : Fin as.size → β → Prop) (hs : ∀ i, p i (f i as[i])) :
-    ∃ eq : (Array.mapIdx as f).size = as.size,
-      ∀ i h, p ⟨i, h⟩ ((Array.mapIdx as f)[i]) :=
-  (mapIdx_induction _ _ (fun _ => True) trivial p fun _ _ => ⟨hs .., trivial⟩).2
-
-@[simp] theorem size_mapIdx (a : Array α) (f : Nat → α → β) : (a.mapIdx f).size = a.size :=
-  (mapIdx_spec (p := fun _ _ => True) (hs := fun _ => trivial)).1
-
-@[simp] theorem getElem_mapIdx (a : Array α) (f : Nat → α → β) (i : Nat)
-    (h : i < (mapIdx a f).size) :
-    (a.mapIdx f)[i] = f i (a[i]'(by simp_all)) :=
-  (mapIdx_spec _ _ (fun i b => b = f i a[i]) fun _ => rfl).2 i (by simp_all)
-
-@[simp] theorem getElem?_mapIdx (a : Array α) (f : Nat → α → β) (i : Nat) :
-    (a.mapIdx f)[i]? =
-      a[i]?.map (f i) := by
-  simp [getElem?_def, size_mapIdx, getElem_mapIdx]
-
-@[simp] theorem toList_mapIdx (a : Array α) (f : Nat → α → β) :
-    (a.mapIdx f).toList = a.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 (l : List α) (f : Nat → α → β) :
-    l.toArray.mapIdx f = (l.mapIdx f).toArray := by
-  ext <;> simp
-
-end List

src/Init/Data/Array/Mem.lean

@@ -10,6 +10,15 @@ 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)

src/Init/Data/BitVec/Basic.lean

@@ -8,13 +8,12 @@ import Init.Data.Fin.Basic
 import Init.Data.Nat.Bitwise.Lemmas
 import Init.Data.Nat.Power2
 import Init.Data.Int.Bitwise
-import Init.Data.BitVec.BasicAux
 
 /-!
-We define the basic algebraic structure of bitvectors. We choose the `Fin` representation over
-others for its relative efficiency (Lean has special support for `Nat`),  and the fact that bitwise
-operations on `Fin` are already defined. Some other possible representations are `List Bool`,
-`{ l : List Bool // l.length = w }`, `Fin w → Bool`.
+We define bitvectors. We choose the `Fin` representation over others for its relative efficiency
+(Lean has special support for `Nat`), alignment with `UIntXY` types which are also represented
+with `Fin`, and the fact that bitwise operations on `Fin` are already defined. Some other possible
+representations are `List Bool`, `{ l : List Bool // l.length = w }`, `Fin w → Bool`.
 
 We define many of the bitvector operations from the
 [`QF_BV` logic](https://smtlib.cs.uiowa.edu/logics-all.shtml#QF_BV).
@@ -23,12 +22,60 @@ of SMT-LIBv2.
 
 set_option linter.missingDocs true
 
+/--
+A bitvector of the specified width.
+
+This is represented as the underlying `Nat` number in both the runtime
+and the kernel, inheriting all the special support for `Nat`.
+-/
+structure BitVec (w : Nat) where
+  /-- Construct a `BitVec w` from a number less than `2^w`.
+  O(1), because we use `Fin` as the internal representation of a bitvector. -/
+  ofFin ::
+  /-- Interpret a bitvector as a number less than `2^w`.
+  O(1), because we use `Fin` as the internal representation of a bitvector. -/
+  toFin : Fin (2^w)
+
+/--
+Bitvectors have decidable equality. This should be used via the instance `DecidableEq (BitVec n)`.
+-/
+-- We manually derive the `DecidableEq` instances for `BitVec` because
+-- we want to have builtin support for bit-vector literals, and we
+-- need a name for this function to implement `canUnfoldAtMatcher` at `WHNF.lean`.
+def BitVec.decEq (x y : BitVec n) : Decidable (x = y) :=
+  match x, y with
+  | ⟨n⟩, ⟨m⟩ =>
+    if h : n = m then
+      isTrue (h ▸ rfl)
+    else
+      isFalse (fun h' => BitVec.noConfusion h' (fun h' => absurd h' h))
+
+instance : DecidableEq (BitVec n) := BitVec.decEq
+
 namespace BitVec
 
 section Nat
 
+/-- The `BitVec` with value `i`, given a proof that `i < 2^n`. -/
+@[match_pattern]
+protected def ofNatLt {n : Nat} (i : Nat) (p : i < 2^n) : BitVec n where
+  toFin := ⟨i, p⟩
+
+/-- The `BitVec` with value `i mod 2^n`. -/
+@[match_pattern]
+protected def ofNat (n : Nat) (i : Nat) : BitVec n where
+  toFin := Fin.ofNat' (2^n) i
+
+instance instOfNat : OfNat (BitVec n) i where ofNat := .ofNat n i
 instance natCastInst : NatCast (BitVec w) := ⟨BitVec.ofNat w⟩
 
+/-- Given a bitvector `x`, return the underlying `Nat`. This is O(1) because `BitVec` is a
+(zero-cost) wrapper around a `Nat`. -/
+protected def toNat (x : BitVec n) : Nat := x.toFin.val
+
+/-- Return the bound in terms of toNat. -/
+theorem isLt (x : BitVec w) : x.toNat < 2^w := x.toFin.isLt
+
 @[deprecated isLt (since := "2024-03-12")]
 theorem toNat_lt (x : BitVec n) : x.toNat < 2^n := x.isLt
 
@@ -191,6 +238,22 @@ end repr_toString
 
 section arithmetic
 
+/--
+Addition for bit vectors. This can be interpreted as either signed or unsigned addition
+modulo `2^n`.
+
+SMT-Lib name: `bvadd`.
+-/
+protected def add (x y : BitVec n) : BitVec n := .ofNat n (x.toNat + y.toNat)
+instance : Add (BitVec n) := ⟨BitVec.add⟩
+
+/--
+Subtraction for bit vectors. This can be interpreted as either signed or unsigned subtraction
+modulo `2^n`.
+-/
+protected def sub (x y : BitVec n) : BitVec n := .ofNat n ((2^n - y.toNat) + x.toNat)
+instance : Sub (BitVec n) := ⟨BitVec.sub⟩
+
 /--
 Negation for bit vectors. This can be interpreted as either signed or unsigned negation
 modulo `2^n`.
@@ -324,6 +387,10 @@ SMT-Lib name: `bvult`.
 -/
 protected def ult (x y : BitVec n) : Bool := x.toNat < y.toNat
 
+instance : LT (BitVec n) where lt := (·.toNat < ·.toNat)
+instance (x y : BitVec n) : Decidable (x < y) :=
+  inferInstanceAs (Decidable (x.toNat < y.toNat))
+
 /--
 Unsigned less-than-or-equal-to for bit vectors.
 
@@ -331,6 +398,10 @@ SMT-Lib name: `bvule`.
 -/
 protected def ule (x y : BitVec n) : Bool := x.toNat ≤ y.toNat
 
+instance : LE (BitVec n) where le := (·.toNat ≤ ·.toNat)
+instance (x y : BitVec n) : Decidable (x ≤ y) :=
+  inferInstanceAs (Decidable (x.toNat ≤ y.toNat))
+
 /--
 Signed less-than for bit vectors.
 
@@ -634,16 +705,6 @@ 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/BasicAux.lean

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

src/Init/Data/BitVec/Bitblast.lean

@@ -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
@@ -291,21 +267,6 @@ theorem add_eq_adc (w : Nat) (x y : BitVec w) : x + y = (adc x y false).snd := b
 
 /-! ### add -/
 
-theorem getMsbD_add {i : Nat} {i_lt : i < w} {x y : BitVec w} :
-    getMsbD (x + y) i =
-      Bool.xor (getMsbD x i) (Bool.xor (getMsbD y i) (carry (w - 1 - i) x y false)) := by
-  simp [getMsbD, getLsbD_add, i_lt, show w - 1 - i < w by omega]
-
-theorem msb_add {w : Nat} {x y: BitVec w} :
-    (x + y).msb =
-      Bool.xor x.msb (Bool.xor y.msb (carry (w - 1) x y false)) := by
-  simp only [BitVec.msb, BitVec.getMsbD]
-  by_cases h : w ≤ 0
-  · simp [h, show w = 0 by omega]
-  · rw [getLsbD_add (x := x)]
-    simp [show w > 0 by omega]
-    omega
-
 /-- Adding a bitvector to its own complement yields the all ones bitpattern -/
 @[simp] theorem add_not_self (x : BitVec w) : x + ~~~x = allOnes w := by
   rw [add_eq_adc, adc, iunfoldr_replace (fun _ => false) (allOnes w)]
@@ -331,26 +292,6 @@ theorem add_eq_or_of_and_eq_zero {w : Nat} (x y : BitVec w)
       simp_all [hx]
     · by_cases hx : x.getLsbD i <;> simp_all [hx]
 
-/-! ### Sub-/
-
-theorem getLsbD_sub {i : Nat} {i_lt : i < w} {x y : BitVec w} :
-    (x - y).getLsbD i
-      = (x.getLsbD i ^^ ((~~~y + 1#w).getLsbD i ^^ carry i x (~~~y + 1#w) false)) := by
-  rw [sub_toAdd, BitVec.neg_eq_not_add, getLsbD_add]
-  omega
-
-theorem getMsbD_sub {i : Nat} {i_lt : i < w} {x y : BitVec w} :
-    (x - y).getMsbD i =
-      (x.getMsbD i ^^ ((~~~y + 1).getMsbD i ^^ carry (w - 1 - i) x (~~~y + 1) false)) := by
-  rw [sub_toAdd, neg_eq_not_add, getMsbD_add]
-  · rfl
-  · omega
-
-theorem msb_sub {x y: BitVec w} :
-    (x - y).msb
-      = (x.msb ^^ ((~~~y + 1#w).msb ^^ carry (w - 1 - 0) x (~~~y + 1#w) false)) := by
-  simp [sub_toAdd, BitVec.neg_eq_not_add, msb_add]
-
 /-! ### Negation -/
 
 theorem bit_not_testBit (x : BitVec w) (i : Fin w) :
@@ -376,117 +317,6 @@ 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

src/Init/Data/BitVec/Lemmas.lean

@@ -286,19 +286,6 @@ theorem getLsbD_ofNat (n : Nat) (x : Nat) (i : Nat) :
 
 @[simp] theorem getMsbD_zero : (0#w).getMsbD i = false := by simp [getMsbD]
 
-@[simp] theorem getLsbD_one : (1#w).getLsbD i = (decide (0 < w) && decide (i = 0)) := by
-  simp only [getLsbD, toNat_ofNat, Nat.testBit_mod_two_pow]
-  by_cases h : i = 0
-    <;> simp [h, Nat.testBit_to_div_mod, Nat.div_eq_of_lt]
-
-@[simp] theorem getElem_one (h : i < w) : (1#w)[i] = decide (i = 0) := by
-  simp [← getLsbD_eq_getElem, getLsbD_one, h, show 0 < w by omega]
-
-/-- The msb at index `w-1` is the least significant bit, and is true when the width is nonzero. -/
-@[simp] theorem getMsbD_one : (1#w).getMsbD i = (decide (i = w - 1) && decide (0 < w)) := by
-  simp only [getMsbD]
-  by_cases h : 0 < w <;> by_cases h' : i = w - 1 <;> simp [h, h'] <;> omega
-
 @[simp] theorem toNat_mod_cancel (x : BitVec n) : x.toNat % (2^n) = x.toNat :=
   Nat.mod_eq_of_lt x.isLt
 
@@ -316,12 +303,6 @@ 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)
 
@@ -366,10 +347,6 @@ theorem getElem_ofBool {b : Bool} {i : Nat} : (ofBool b)[0] = b := by
 
 @[simp] theorem msb_zero : (0#w).msb = false := by simp [BitVec.msb, getMsbD]
 
-@[simp] theorem msb_one : (1#w).msb = decide (w = 1) := by
-  simp [BitVec.msb, getMsbD_one, ← Bool.decide_and]
-  omega
-
 theorem msb_eq_getLsbD_last (x : BitVec w) :
     x.msb = x.getLsbD (w - 1) := by
   simp only [BitVec.msb, getMsbD]
@@ -1062,7 +1039,7 @@ 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
 
@@ -1232,11 +1209,7 @@ 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]
 
 /--
@@ -1391,10 +1364,6 @@ 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
@@ -1792,7 +1761,7 @@ 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
 
@@ -1917,31 +1886,6 @@ 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
@@ -2013,10 +1957,6 @@ 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.
@@ -2039,8 +1979,6 @@ 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]
@@ -2053,8 +1991,18 @@ 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) :=
@@ -2125,11 +2073,6 @@ theorem sub_eq_xor {a b : BitVec 1} : a - b = a ^^^ b := by
   have hb : b = 0 ∨ b = 1 := eq_zero_or_eq_one _
   rcases ha with h | h <;> (rcases hb with h' | h' <;> (simp [h, h']))
 
-@[simp]
-theorem sub_eq_self {x : BitVec 1} : -x = x := by
-  have ha : x = 0 ∨ x = 1 := eq_zero_or_eq_one _
-  rcases ha with h | h <;> simp [h]
-
 theorem not_neg (x : BitVec w) : ~~~(-x) = x + -1#w := by
   rcases w with _ | w
   · apply Subsingleton.elim
@@ -2146,6 +2089,17 @@ 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
@@ -2173,23 +2127,18 @@ 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
@@ -2370,11 +2319,6 @@ 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]
-
 /-! ### sdiv -/
 
 /-- Equation theorem for `sdiv` in terms of `udiv`. -/
@@ -2397,24 +2341,6 @@ theorem toNat_sdiv {x y : BitVec w} : (x.sdiv y).toNat =
   simp only [sdiv_eq, toNat_udiv]
   by_cases h : x.msb <;> by_cases h' : y.msb <;> simp [h, h']
 
-@[simp]
-theorem zero_sdiv {x : BitVec w} : (0#w).sdiv x = 0#w := by
-  simp only [sdiv_eq]
-  rcases x.msb with msb | msb <;> simp
-
-@[simp]
-theorem sdiv_zero {x : BitVec n} : x.sdiv 0#n = 0#n := by
-  simp only [sdiv_eq, msb_zero]
-  rcases x.msb with msb | msb <;> apply eq_of_toNat_eq <;> simp
-
-@[simp]
-theorem sdiv_one {x : BitVec w} : x.sdiv 1#w = x := by
-  simp only [sdiv_eq]
-  · by_cases h : w = 1
-    · subst h
-      rcases x.msb with msb | msb <;> simp
-    · rcases x.msb with msb | msb <;> simp [h]
-
 theorem sdiv_eq_and (x y : BitVec 1) : x.sdiv y = x &&& y := by
   have hx : x = 0#1 ∨ x = 1#1 := by bv_omega
   have hy : y = 0#1 ∨ y = 1#1 := by bv_omega
@@ -2423,35 +2349,9 @@ theorem sdiv_eq_and (x y : BitVec 1) : x.sdiv y = x &&& y := by
       rfl
 
 @[simp]
-theorem sdiv_self {x : BitVec w} :
-    x.sdiv x = if x == 0#w then 0#w else 1#w := by
-  simp [sdiv_eq]
-  · by_cases h : w = 1
-    · subst h
-      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
-
-/-! ### 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
+theorem sdiv_zero {x : BitVec n} : x.sdiv 0#n = 0#n := by
+  simp only [sdiv_eq, msb_zero]
+  rcases x.msb with msb | msb <;> apply eq_of_toNat_eq <;> simp
 
 /-! ### smod -/
 
@@ -2726,21 +2626,6 @@ 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
@@ -2768,6 +2653,14 @@ theorem twoPow_zero {w : Nat} : twoPow w 0 = 1#w := by
   apply eq_of_toNat_eq
   simp
 
+@[simp]
+theorem getLsbD_one {w i : Nat} : (1#w).getLsbD i = (decide (0 < w) && decide (0 = i)) := by
+  rw [← twoPow_zero, getLsbD_twoPow]
+
+@[simp]
+theorem getElem_one {w i : Nat} (h : i < w) : (1#w)[i] = decide (i = 0) := by
+  rw [← twoPow_zero, getElem_twoPow]
+
 theorem shiftLeft_eq_mul_twoPow (x : BitVec w) (n : Nat) :
     x <<< n = x * (BitVec.twoPow w n) := by
   ext i
@@ -2787,6 +2680,7 @@ theorem shiftLeft_eq_mul_twoPow (x : BitVec w) (n : Nat) :
 @[simp] theorem zero_concat_true : concat 0#w true = 1#(w + 1) := by
   ext
   simp [getLsbD_concat]
+  omega
 
 /- ### setWidth, setWidth, and bitwise operations -/
 
@@ -2827,7 +2721,7 @@ theorem and_one_eq_setWidth_ofBool_getLsbD {x : BitVec w} :
   ext i
   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
+  by_cases h : (0 = (i : Nat)) <;> simp [h] <;> omega
 
 @[simp]
 theorem replicate_zero_eq {x : BitVec w} : x.replicate 0 = 0#0 := by
@@ -2886,14 +2780,6 @@ 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`.
 -/
@@ -2916,21 +2802,6 @@ 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
@@ -2938,10 +2809,6 @@ 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
@@ -2958,10 +2825,6 @@ 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. -/
@@ -3054,38 +2917,6 @@ 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 -/
 
@@ -3294,10 +3125,4 @@ 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/Char/Basic.lean

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 -/
 prelude
-import Init.Data.UInt.BasicAux
+import Init.Data.UInt.Basic
 
 /-- Determines if the given integer is a valid [Unicode scalar value](https://www.unicode.org/glossary/#unicode_scalar_value).
 
@@ -42,10 +42,8 @@ theorem isValidUInt32 (n : Nat) (h : isValidCharNat n) : n < UInt32.size := by
 
 theorem isValidChar_of_isValidCharNat (n : Nat) (h : isValidCharNat n) : isValidChar (UInt32.ofNat' n (isValidUInt32 n h)) :=
   match h with
-  | Or.inl h =>
-    Or.inl (UInt32.ofNat'_lt_of_lt _ (by decide) h)
-  | Or.inr ⟨h₁, h₂⟩ =>
-    Or.inr ⟨UInt32.lt_ofNat'_of_lt _ (by decide) h₁, UInt32.ofNat'_lt_of_lt _ (by decide) h₂⟩
+  | Or.inl h        => Or.inl h
+  | Or.inr ⟨h₁, h₂⟩ => Or.inr ⟨h₁, h₂⟩
 
 theorem isValidChar_zero : isValidChar 0 :=
   Or.inl (by decide)
@@ -59,7 +57,7 @@ theorem isValidChar_zero : isValidChar 0 :=
   c.val.toUInt8
 
 /-- The numbers from 0 to 256 are all valid UTF-8 characters, so we can embed one in the other. -/
-def ofUInt8 (n : UInt8) : Char := ⟨n.toUInt32, .inl (Nat.lt_trans n.toBitVec.isLt (by decide))⟩
+def ofUInt8 (n : UInt8) : Char := ⟨n.toUInt32, .inl (Nat.lt_trans n.1.2 (by decide))⟩
 
 instance : Inhabited Char where
   default := 'A'

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/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`, `insert`, `modify`, `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
@@ -563,13 +558,10 @@ def flatten : List (List α) → List α
 
 @[deprecated flatten (since := "2024-10-14"), inherit_doc flatten] abbrev join := @flatten
 
-/-! ### singleton -/
+/-! ### pure -/
 
-/-- `singleton x = [x]`. -/
-@[inline] protected def singleton {α : Type u} (a : α) : List α := [a]
-
-set_option linter.missingDocs false in
-@[deprecated singleton (since := "2024-10-16")] protected abbrev pure := @singleton
+/-- `pure x = [x]` is the `pure` operation of the list monad. -/
+@[inline] protected def pure {α : Type u} (a : α) : List α := [a]
 
 /-! ### flatMap -/
 
@@ -1119,35 +1111,6 @@ theorem replace_cons [BEq α] {a : α} :
 @[inline] protected def insert [BEq α] (a : α) (l : List α) : List α :=
   if l.elem a then l else a :: l
 
-/-! ### 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)
-
 /-! ### erase -/
 
 /--
@@ -1442,25 +1405,12 @@ def unzip : List (α × β) → List α × List β
 
 /-! ## Ranges and enumeration -/
 
-/-- Sum of a list.
-
-`List.sum [a, b, c] = a + (b + (c + 0))` -/
-def sum {α} [Add α] [Zero α] : List α → α :=
-  foldr (· + ·) 0
-
-@[simp] theorem sum_nil [Add α] [Zero α] : ([] : List α).sum = 0 := rfl
-@[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")]
+-- This is not in the `List` namespace as later `List.sum` will be defined polymorphically.
 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 -/
@@ -1639,23 +1589,23 @@ 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**.
@@ -1666,8 +1616,6 @@ 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

@@ -215,6 +215,27 @@ 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
 
+@[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
+
+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
     | [], b, _    => pure b
@@ -233,15 +254,14 @@ def findSomeM? {m : Type u → Type v} [Monad m] {α : Type w} {β : Type u} (f
 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

@@ -153,10 +153,10 @@ 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
+    countP p l.flatten = Nat.sum (l.map (countP p)) := by
   simp only [countP_eq_length_filter, filter_flatten]
   simp [countP_eq_length_filter']
 
@@ -232,7 +232,7 @@ theorem count_singleton (a b : α) : count a [b] = if b == a then 1 else 0 := by
 @[simp] theorem count_append (a : α) : ∀ l₁ l₂, count a (l₁ ++ l₂) = count a l₁ + count a l₂ :=
   countP_append _
 
-theorem count_flatten (a : α) (l : List (List α)) : count a l.flatten = (l.map (count a)).sum := by
+theorem count_flatten (a : α) (l : List (List α)) : count a l.flatten = Nat.sum (l.map (count a)) := by
   simp only [count_eq_countP, countP_flatten, count_eq_countP']
 
 @[deprecated count_flatten (since := "2024-10-14")] abbrev count_join := @count_flatten
@@ -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

@@ -179,7 +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 :=
@@ -436,7 +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 :=
@@ -562,7 +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
 
@@ -595,14 +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) :
@@ -792,7 +793,7 @@ theorem findIdx?_of_eq_none {xs : List α} {p : α → Bool} (w : xs.findIdx? p
 theorem findIdx?_flatten {l : List (List α)} {p : α → Bool} :
     l.flatten.findIdx? p =
       (l.findIdx? (·.any p)).map
-        fun i => ((l.take i).map List.length).sum +
+        fun i => Nat.sum ((l.take i).map List.length) +
           (l[i]?.map fun xs => xs.findIdx p).getD 0 := by
   induction l with
   | nil => simp

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`, `erase`, `eraseIdx`, `zipWith`,
+`take`, `takeWhile`, `dropLast`, `replace`, `erase`, `eraseIdx`, `zipWith`,
 `enumFrom`, and `intercalate`.
 
 -/
@@ -197,24 +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]
-
 /-! ### 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 ..)
@@ -1043,6 +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
@@ -1076,21 +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! -/
-
-@[simp] theorem getLast!_nil [Inhabited α] : ([] : List α).getLast! = default := rfl
-
-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 -/
@@ -2078,7 +2070,8 @@ theorem eq_nil_or_concat : ∀ l : List α, l = [] ∨ ∃ L b, l = concat L b
 
 /-! ### flatten -/
 
-@[simp] theorem length_flatten (L : List (List α)) : (flatten L).length = (L.map length).sum := by
+
+@[simp] theorem length_flatten (L : List (List α)) : (flatten L).length = Nat.sum (L.map length) := by
   induction L with
   | nil => rfl
   | cons =>
@@ -3328,7 +3321,7 @@ 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 [*]
 
@@ -76,16 +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 [*]
-
 /-! ### forM -/
 
 -- We use `List.forM` as the simp normal form, rather that `ForM.forM`.
@@ -101,129 +87,6 @@ theorem foldrM_map [Monad m] [LawfulMonad m] (f : β₁ → β₂) (g : β₂
     (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 <$>
-      l.attach.foldlM (fun b a => match b with
-        | .yield b => f a.1 a.2 b
-        | .done b => pure (.done b)) (ForInStep.yield init) := by
-  induction l generalizing init with
-  | nil => simp
-  | cons a as ih =>
-    simp only [forIn'_cons, attach_cons, foldlM_cons, _root_.map_bind]
-    congr 1
-    funext x
-    match x with
-    | .done b =>
-      clear ih
-      dsimp
-      induction as with
-      | nil => simp
-      | cons a as ih =>
-        simp only [attach_cons, map_cons, map_map, Function.comp_def, foldlM_cons, pure_bind]
-        specialize ih (fun a m b => f a (by
-          simp only [mem_cons] at m
-          rcases m with rfl|m
-          · apply mem_cons_self
-          · exact mem_cons_of_mem _ (mem_cons_of_mem _ m)) b)
-        simp [ih, List.foldlM_map]
-    | .yield b =>
-      simp [ih, List.foldlM_map]
-
-/--
-We can express a for loop over a list as a fold,
-in which whenever we reach `.done b` we keep that value through the rest of the fold.
--/
-theorem forIn_eq_foldlM [Monad m] [LawfulMonad m]
-    (f : α → β → m (ForInStep β)) (init : β) (l : List α) :
-    forIn l init f = ForInStep.value <$>
-      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]
-
 /-! ### allM -/
 
 theorem allM_eq_not_anyM_not [Monad m] [LawfulMonad m] (p : α → m Bool) (as : List α) :

src/Init/Data/List/Nat.lean

@@ -12,5 +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

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/Modify.lean

@@ -1,295 +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) ..⟩
-
-/-! ### 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

@@ -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
@@ -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

@@ -1,55 +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
-
-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/Range.lean

@@ -20,6 +20,7 @@ open Nat
 
 /-! ## Ranges and enumeration -/
 
+
 /-! ### range' -/
 
 theorem range'_succ (s n step) : range' s (n + 1) step = s :: range' (s + step) n step := by

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} :
@@ -976,7 +976,7 @@ theorem mem_of_mem_drop {n} {l : List α} (h : a ∈ l.drop n) : a ∈ l :=
   drop_subset _ _ h
 
 theorem drop_suffix_drop_left (l : List α) {m n : Nat} (h : m ≤ n) : drop n l <:+ drop m l := by
-  rw [← Nat.sub_add_cancel h, Nat.add_comm, ← drop_drop]
+  rw [← Nat.sub_add_cancel h, ← drop_drop]
   apply drop_suffix
 
 -- See `Init.Data.List.Nat.TakeDrop` for `take_prefix_take_left`.

src/Init/Data/List/TakeDrop.lean

@@ -97,14 +97,14 @@ theorem get?_take {l : List α} {n m : Nat} (h : m < n) : (l.take n).get? m = l.
 
 theorem getElem?_take_of_succ {l : List α} {n : Nat} : (l.take (n + 1))[n]? = l[n]? := by simp
 
-@[simp] theorem drop_drop (n : Nat) : ∀ (m) (l : List α), drop n (drop m l) = drop (m + n) l
+@[simp] theorem drop_drop (n : Nat) : ∀ (m) (l : List α), drop n (drop m l) = drop (n + m) l
   | m, [] => by simp
   | 0, l => by simp
   | m + 1, a :: l =>
     calc
       drop n (drop (m + 1) (a :: l)) = drop n (drop m l) := rfl
-      _ = drop (m + n) l := drop_drop n m l
-      _ = drop ((m + 1) + n) (a :: l) := by rw [Nat.add_right_comm]; rfl
+      _ = drop (n + m) l := drop_drop n m l
+      _ = drop (n + (m + 1)) (a :: l) := rfl
 
 theorem take_drop : ∀ (m n : Nat) (l : List α), take n (drop m l) = drop m (take (m + n) l)
   | 0, _, _ => by simp
@@ -112,7 +112,7 @@ theorem take_drop : ∀ (m n : Nat) (l : List α), take n (drop m l) = drop m (t
   | _+1, _, _ :: _ => by simpa [Nat.succ_add, take_succ_cons, drop_succ_cons] using take_drop ..
 
 @[deprecated drop_drop (since := "2024-06-15")]
-theorem drop_add (m n) (l : List α) : drop (m + n) l = drop n (drop m l) := by
+theorem drop_add (m n) (l : List α) : drop (m + n) l = drop m (drop n l) := by
   simp [drop_drop]
 
 @[simp]
@@ -126,7 +126,7 @@ theorem tail_drop (l : List α) (n : Nat) : (l.drop n).tail = l.drop (n + 1) :=
 
 @[simp]
 theorem drop_tail (l : List α) (n : Nat) : l.tail.drop n = l.drop (n + 1) := by
-  rw [Nat.add_comm, ← drop_drop, drop_one]
+  rw [← drop_drop, drop_one]
 
 @[simp]
 theorem drop_eq_nil_iff {l : List α} {k : Nat} : l.drop k = [] ↔ l.length ≤ k := by
@@ -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

@@ -131,7 +131,7 @@ theorem or_exists_add_one : p 0 ∨ (Exists fun n => p (n + 1)) ↔ Exists p :=
 @[simp] theorem blt_eq : (Nat.blt x y = true) = (x < y) := propext <| Iff.intro Nat.le_of_ble_eq_true Nat.ble_eq_true_of_le
 
 instance : LawfulBEq Nat where
-  eq_of_beq h := by simpa using h
+  eq_of_beq h := Nat.eq_of_beq_eq_true h
   rfl := by simp [BEq.beq]
 
 theorem beq_eq_true_eq (a b : Nat) : ((a == b) = true) = (a = b) := by simp
@@ -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 :=
@@ -796,8 +796,6 @@ theorem pos_pow_of_pos {n : Nat} (m : Nat) (h : 0 < n) : 0 < n^m :=
   | zero => cases h
   | succ n => simp [Nat.pow_succ]
 
-protected theorem two_pow_pos (w : Nat) : 0 < 2^w := Nat.pos_pow_of_pos _ (by decide)
-
 instance {n m : Nat} [NeZero n] : NeZero (n^m) :=
   ⟨Nat.ne_zero_iff_zero_lt.mpr (Nat.pos_pow_of_pos m (pos_of_neZero _))⟩
 

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/Nat/Power2.lean

@@ -8,6 +8,8 @@ import Init.Data.Nat.Linear
 
 namespace Nat
 
+protected theorem two_pow_pos (w : Nat) : 0 < 2^w := Nat.pos_pow_of_pos _ (by decide)
+
 theorem nextPowerOfTwo_dec {n power : Nat} (h₁ : power > 0) (h₂ : power < n) : n - power * 2 < n - power := by
   have : power * 2 = power + power := by simp_arith
   rw [this, Nat.sub_add_eq]

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
 

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

@@ -374,15 +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/Prod.lean

@@ -7,8 +7,6 @@ prelude
 import Init.SimpLemmas
 import Init.NotationExtra
 
-namespace Prod
-
 instance [BEq α] [BEq β] [LawfulBEq α] [LawfulBEq β] : LawfulBEq (α × β) where
   eq_of_beq {a b} (h : a.1 == b.1 && a.2 == b.2) := by
     cases a; cases b
@@ -16,65 +14,9 @@ instance [BEq α] [BEq β] [LawfulBEq α] [LawfulBEq β] : LawfulBEq (α × β)
   rfl {a} := by cases a; simp [BEq.beq, LawfulBEq.rfl]
 
 @[simp]
-protected theorem «forall» {p : α × β → Prop} : (∀ x, p x) ↔ ∀ a b, p (a, b) :=
+protected theorem Prod.forall {p : α × β → Prop} : (∀ x, p x) ↔ ∀ a b, p (a, b) :=
   ⟨fun h a b ↦ h (a, b), fun h ⟨a, b⟩ ↦ h a b⟩
 
 @[simp]
-protected theorem «exists» {p : α × β → Prop} : (∃ x, p x) ↔ ∃ a b, p (a, b) :=
+protected theorem Prod.exists {p : α × β → Prop} : (∃ x, p x) ↔ ∃ a b, p (a, b) :=
   ⟨fun ⟨⟨a, b⟩, h⟩ ↦ ⟨a, b, h⟩, fun ⟨a, b, h⟩ ↦ ⟨⟨a, b⟩, h⟩⟩
-
-@[simp] theorem map_id : Prod.map (@id α) (@id β) = id := rfl
-
-@[simp] theorem map_id' : Prod.map (fun a : α => a) (fun b : β => b) = fun x ↦ x := rfl
-
-/--
-Composing a `Prod.map` with another `Prod.map` is equal to
-a single `Prod.map` of composed functions.
--/
-theorem map_comp_map (f : α → β) (f' : γ → δ) (g : β → ε) (g' : δ → ζ) :
-    Prod.map g g' ∘ Prod.map f f' = Prod.map (g ∘ f) (g' ∘ f') :=
-  rfl
-
-/--
-Composing a `Prod.map` with another `Prod.map` is equal to
-a single `Prod.map` of composed functions, fully applied.
--/
-theorem map_map (f : α → β) (f' : γ → δ) (g : β → ε) (g' : δ → ζ) (x : α × γ) :
-    Prod.map g g' (Prod.map f f' x) = Prod.map (g ∘ f) (g' ∘ f') x :=
-  rfl
-
-/-- Swap the factors of a product. `swap (a, b) = (b, a)` -/
-def swap : α × β → β × α := fun p => (p.2, p.1)
-
-@[simp]
-theorem swap_swap : ∀ x : α × β, swap (swap x) = x
-  | ⟨_, _⟩ => rfl
-
-@[simp]
-theorem fst_swap {p : α × β} : (swap p).1 = p.2 :=
-  rfl
-
-@[simp]
-theorem snd_swap {p : α × β} : (swap p).2 = p.1 :=
-  rfl
-
-@[simp]
-theorem swap_prod_mk {a : α} {b : β} : swap (a, b) = (b, a) :=
-  rfl
-
-@[simp]
-theorem swap_swap_eq : swap ∘ swap = @id (α × β) :=
-  funext swap_swap
-
-@[simp]
-theorem swap_inj {p q : α × β} : swap p = swap q ↔ p = q := by
-  cases p; cases q; simp [and_comm]
-
-/--
-For two functions `f` and `g`, the composition of `Prod.map f g` with `Prod.swap`
-is equal to the composition of `Prod.swap` with `Prod.map g f`.
--/
-theorem map_comp_swap (f : α → β) (g : γ → δ) :
-    Prod.map f g ∘ Prod.swap = Prod.swap ∘ Prod.map g f := rfl
-
-end Prod

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.Basic
+import Init.Control.Id
 open Sum Subtype Nat
 
 open Std

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

@@ -1,465 +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
-
-/-- 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

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
 
@@ -316,9 +317,6 @@ theorem _root_.Char.utf8Size_le_four (c : Char) : c.utf8Size ≤ 4 := by
 
 @[simp] theorem pos_add_char (p : Pos) (c : Char) : (p + c).byteIdx = p.byteIdx + c.utf8Size := rfl
 
-protected theorem Pos.ne_zero_of_lt : {a b : Pos} → a < b → b ≠ 0
-  | _, _, hlt, rfl => Nat.not_lt_zero _ hlt
-
 theorem lt_next (s : String) (i : Pos) : i.1 < (s.next i).1 :=
   Nat.add_lt_add_left (Char.utf8Size_pos _) _
 
@@ -1023,66 +1021,6 @@ instance hasBeq : BEq Substring := ⟨beq⟩
 def sameAs (ss1 ss2 : Substring) : Bool :=
   ss1.startPos == ss2.startPos && ss1 == ss2
 
-/--
-Returns the longest common prefix of two substrings.
-The returned substring will use the same underlying string as `s`.
--/
-def commonPrefix (s t : Substring) : Substring :=
-  { s with stopPos := loop s.startPos t.startPos }
-where
-  /-- Returns the ending position of the common prefix, working up from `spos, tpos`. -/
-  loop spos tpos :=
-    if h : spos < s.stopPos ∧ tpos < t.stopPos then
-      if s.str.get spos == t.str.get tpos then
-        have := Nat.sub_lt_sub_left h.1 (s.str.lt_next spos)
-        loop (s.str.next spos) (t.str.next tpos)
-      else
-        spos
-    else
-      spos
-  termination_by s.stopPos.byteIdx - spos.byteIdx
-
-/--
-Returns the longest common suffix of two substrings.
-The returned substring will use the same underlying string as `s`.
--/
-def commonSuffix (s t : Substring) : Substring :=
-  { s with startPos := loop s.stopPos t.stopPos }
-where
-  /-- Returns the starting position of the common prefix, working down from `spos, tpos`. -/
-  loop spos tpos :=
-    if h : s.startPos < spos ∧ t.startPos < tpos then
-      let spos' := s.str.prev spos
-      let tpos' := t.str.prev tpos
-      if s.str.get spos' == t.str.get tpos' then
-        have : spos' < spos := s.str.prev_lt_of_pos spos (String.Pos.ne_zero_of_lt h.1)
-        loop spos' tpos'
-      else
-        spos
-    else
-      spos
-  termination_by spos.byteIdx
-
-/--
-If `pre` is a prefix of `s`, i.e. `s = pre ++ t`, returns the remainder `t`.
--/
-def dropPrefix? (s : Substring) (pre : Substring) : Option Substring :=
-  let t := s.commonPrefix pre
-  if t.bsize = pre.bsize then
-    some { s with startPos := t.stopPos }
-  else
-    none
-
-/--
-If `suff` is a suffix of `s`, i.e. `s = t ++ suff`, returns the remainder `t`.
--/
-def dropSuffix? (s : Substring) (suff : Substring) : Option Substring :=
-  let t := s.commonSuffix suff
-  if t.bsize = suff.bsize then
-    some { s with stopPos := t.startPos }
-  else
-    none
-
 end Substring
 
 namespace String
@@ -1144,28 +1082,6 @@ namespace String
 @[inline] def decapitalize (s : String) :=
   s.set 0 <| s.get 0 |>.toLower
 
-/--
-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
-
-/--
-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
-
-/-- `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 :=
-  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 :=
-  s.dropSuffix? suff |>.map Substring.toString |>.getD s
-
 end String
 
 namespace Char

src/Init/Data/String/Extra.lean

@@ -5,7 +5,6 @@ Author: Leonardo de Moura
 -/
 prelude
 import Init.Data.ByteArray
-import Init.Data.UInt.Lemmas
 
 namespace String
 
@@ -21,14 +20,14 @@ def toNat! (s : String) : Nat :=
 def utf8DecodeChar? (a : ByteArray) (i : Nat) : Option Char := do
   let c ← a[i]?
   if c &&& 0x80 == 0 then
-    some ⟨c.toUInt32, .inl (Nat.lt_trans c.toBitVec.isLt (by decide))⟩
+    some ⟨c.toUInt32, .inl (Nat.lt_trans c.1.2 (by decide))⟩
   else if c &&& 0xe0 == 0xc0 then
     let c1 ← a[i+1]?
     guard (c1 &&& 0xc0 == 0x80)
     let r := ((c &&& 0x1f).toUInt32 <<< 6) ||| (c1 &&& 0x3f).toUInt32
     guard (0x80 ≤ r)
     -- TODO: Prove h from the definition of r once we have the necessary lemmas
-    if h : r < 0xd800 then some ⟨r, .inl (UInt32.toNat_lt_of_lt (by decide) h)⟩ else none
+    if h : r < 0xd800 then some ⟨r, .inl h⟩ else none
   else if c &&& 0xf0 == 0xe0 then
     let c1 ← a[i+1]?
     let c2 ← a[i+2]?
@@ -39,14 +38,7 @@ def utf8DecodeChar? (a : ByteArray) (i : Nat) : Option Char := do
       (c2 &&& 0x3f).toUInt32
     guard (0x800 ≤ r)
     -- TODO: Prove `r < 0x110000` from the definition of r once we have the necessary lemmas
-    if h : r < 0xd800 ∨ 0xdfff < r ∧ r < 0x110000 then
-      have :=
-        match h with
-        | .inl h => Or.inl (UInt32.toNat_lt_of_lt (by decide) h)
-        | .inr h => Or.inr ⟨UInt32.lt_toNat_of_lt (by decide) h.left, UInt32.toNat_lt_of_lt (by decide) h.right⟩
-      some ⟨r, this⟩
-    else
-      none
+    if h : r < 0xd800 ∨ 0xdfff < r ∧ r < 0x110000 then some ⟨r, h⟩ else none
   else if c &&& 0xf8 == 0xf0 then
     let c1 ← a[i+1]?
     let c2 ← a[i+2]?
@@ -58,7 +50,7 @@ def utf8DecodeChar? (a : ByteArray) (i : Nat) : Option Char := do
       ((c2 &&& 0x3f).toUInt32 <<< 6) |||
       (c3 &&& 0x3f).toUInt32
     if h : 0x10000 ≤ r ∧ r < 0x110000 then
-      some ⟨r, .inr ⟨Nat.lt_of_lt_of_le (by decide) (UInt32.le_toNat_of_le (by decide) h.left), UInt32.toNat_lt_of_lt (by decide) h.right⟩⟩
+      some ⟨r, .inr ⟨Nat.lt_of_lt_of_le (by decide) h.1, h.2⟩⟩
     else none
   else
     none

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.Basic
+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.lean

@@ -4,7 +4,6 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Henrik Böving
 -/
 prelude
-import Init.Data.UInt.BasicAux
 import Init.Data.UInt.Basic
 import Init.Data.UInt.Log2
 import Init.Data.UInt.Lemmas

src/Init/Data/UInt/Basic.lean

@@ -4,50 +4,52 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Leonardo de Moura
 -/
 prelude
-import Init.Data.UInt.BasicAux
-import Init.Data.BitVec.Basic
+import Init.Data.Fin.Basic
 
 open Nat
 
+@[extern "lean_uint8_of_nat"]
+def UInt8.ofNat (n : @& Nat) : UInt8 := ⟨Fin.ofNat n⟩
+abbrev Nat.toUInt8 := UInt8.ofNat
+@[extern "lean_uint8_to_nat"]
+def UInt8.toNat (n : UInt8) : Nat := n.val.val
 @[extern "lean_uint8_add"]
-def UInt8.add (a b : UInt8) : UInt8 := ⟨a.toBitVec + b.toBitVec⟩
+def UInt8.add (a b : UInt8) : UInt8 := ⟨a.val + b.val⟩
 @[extern "lean_uint8_sub"]
-def UInt8.sub (a b : UInt8) : UInt8 := ⟨a.toBitVec - b.toBitVec⟩
+def UInt8.sub (a b : UInt8) : UInt8 := ⟨a.val - b.val⟩
 @[extern "lean_uint8_mul"]
-def UInt8.mul (a b : UInt8) : UInt8 := ⟨a.toBitVec * b.toBitVec⟩
+def UInt8.mul (a b : UInt8) : UInt8 := ⟨a.val * b.val⟩
 @[extern "lean_uint8_div"]
-def UInt8.div (a b : UInt8) : UInt8 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
+def UInt8.div (a b : UInt8) : UInt8 := ⟨a.val / b.val⟩
 @[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⟩
+def UInt8.mod (a b : UInt8) : UInt8 := ⟨a.val % b.val⟩
+@[extern "lean_uint8_modn"]
+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⟩
+def UInt8.land (a b : UInt8) : UInt8 := ⟨Fin.land a.val b.val⟩
 @[extern "lean_uint8_lor"]
-def UInt8.lor (a b : UInt8) : UInt8 := ⟨a.toBitVec ||| b.toBitVec⟩
+def UInt8.lor (a b : UInt8) : UInt8 := ⟨Fin.lor a.val b.val⟩
 @[extern "lean_uint8_xor"]
-def UInt8.xor (a b : UInt8) : UInt8 := ⟨a.toBitVec ^^^ b.toBitVec⟩
+def UInt8.xor (a b : UInt8) : UInt8 := ⟨Fin.xor a.val b.val⟩
 @[extern "lean_uint8_shift_left"]
-def UInt8.shiftLeft (a b : UInt8) : UInt8 := ⟨a.toBitVec <<< (mod b 8).toBitVec⟩
+def UInt8.shiftLeft (a b : UInt8) : UInt8 := ⟨a.val <<< (modn b 8).val⟩
 @[extern "lean_uint8_shift_right"]
-def UInt8.shiftRight (a b : UInt8) : UInt8 := ⟨a.toBitVec >>> (mod b 8).toBitVec⟩
-def UInt8.lt (a b : UInt8) : Prop := a.toBitVec < b.toBitVec
-def UInt8.le (a b : UInt8) : Prop := a.toBitVec ≤ b.toBitVec
+def UInt8.shiftRight (a b : UInt8) : UInt8 := ⟨a.val >>> (modn b 8).val⟩
+def UInt8.lt (a b : UInt8) : Prop := a.val < b.val
+def UInt8.le (a b : UInt8) : Prop := a.val ≤ b.val
 
+instance UInt8.instOfNat : OfNat UInt8 n := ⟨UInt8.ofNat n⟩
 instance : Add UInt8       := ⟨UInt8.add⟩
 instance : Sub UInt8       := ⟨UInt8.sub⟩
 instance : Mul UInt8       := ⟨UInt8.mul⟩
 instance : Mod UInt8       := ⟨UInt8.mod⟩
-
-set_option linter.deprecated false in
 instance : HMod UInt8 Nat UInt8 := ⟨UInt8.modn⟩
-
 instance : Div UInt8       := ⟨UInt8.div⟩
 instance : LT UInt8        := ⟨UInt8.lt⟩
 instance : LE UInt8        := ⟨UInt8.le⟩
 
 @[extern "lean_uint8_complement"]
-def UInt8.complement (a : UInt8) : UInt8 := ⟨~~~a.toBitVec⟩
+def UInt8.complement (a:UInt8) : UInt8 := 0-(a+1)
 
 instance : Complement UInt8 := ⟨UInt8.complement⟩
 instance : AndOp UInt8     := ⟨UInt8.land⟩
@@ -56,58 +58,69 @@ instance : Xor UInt8       := ⟨UInt8.xor⟩
 instance : ShiftLeft UInt8  := ⟨UInt8.shiftLeft⟩
 instance : ShiftRight UInt8 := ⟨UInt8.shiftRight⟩
 
+set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint8_dec_lt"]
 def UInt8.decLt (a b : UInt8) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec < b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n < m))
 
+set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint8_dec_le"]
 def UInt8.decLe (a b : UInt8) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec ≤ b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n <= m))
 
 instance (a b : UInt8) : Decidable (a < b) := UInt8.decLt a b
 instance (a b : UInt8) : Decidable (a ≤ b) := UInt8.decLe a b
 instance : Max UInt8 := maxOfLe
 instance : Min UInt8 := minOfLe
 
+@[extern "lean_uint16_of_nat"]
+def UInt16.ofNat (n : @& Nat) : UInt16 := ⟨Fin.ofNat n⟩
+abbrev Nat.toUInt16 := UInt16.ofNat
+@[extern "lean_uint16_to_nat"]
+def UInt16.toNat (n : UInt16) : Nat := n.val.val
 @[extern "lean_uint16_add"]
-def UInt16.add (a b : UInt16) : UInt16 := ⟨a.toBitVec + b.toBitVec⟩
+def UInt16.add (a b : UInt16) : UInt16 := ⟨a.val + b.val⟩
 @[extern "lean_uint16_sub"]
-def UInt16.sub (a b : UInt16) : UInt16 := ⟨a.toBitVec - b.toBitVec⟩
+def UInt16.sub (a b : UInt16) : UInt16 := ⟨a.val - b.val⟩
 @[extern "lean_uint16_mul"]
-def UInt16.mul (a b : UInt16) : UInt16 := ⟨a.toBitVec * b.toBitVec⟩
+def UInt16.mul (a b : UInt16) : UInt16 := ⟨a.val * b.val⟩
 @[extern "lean_uint16_div"]
-def UInt16.div (a b : UInt16) : UInt16 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
+def UInt16.div (a b : UInt16) : UInt16 := ⟨a.val / b.val⟩
 @[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⟩
+def UInt16.mod (a b : UInt16) : UInt16 := ⟨a.val % b.val⟩
+@[extern "lean_uint16_modn"]
+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⟩
+def UInt16.land (a b : UInt16) : UInt16 := ⟨Fin.land a.val b.val⟩
 @[extern "lean_uint16_lor"]
-def UInt16.lor (a b : UInt16) : UInt16 := ⟨a.toBitVec ||| b.toBitVec⟩
+def UInt16.lor (a b : UInt16) : UInt16 := ⟨Fin.lor a.val b.val⟩
 @[extern "lean_uint16_xor"]
-def UInt16.xor (a b : UInt16) : UInt16 := ⟨a.toBitVec ^^^ b.toBitVec⟩
+def UInt16.xor (a b : UInt16) : UInt16 := ⟨Fin.xor a.val b.val⟩
 @[extern "lean_uint16_shift_left"]
-def UInt16.shiftLeft (a b : UInt16) : UInt16 := ⟨a.toBitVec <<< (mod b 16).toBitVec⟩
+def UInt16.shiftLeft (a b : UInt16) : UInt16 := ⟨a.val <<< (modn b 16).val⟩
+@[extern "lean_uint16_to_uint8"]
+def UInt16.toUInt8 (a : UInt16) : UInt8 := a.toNat.toUInt8
+@[extern "lean_uint8_to_uint16"]
+def UInt8.toUInt16 (a : UInt8) : UInt16 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
 @[extern "lean_uint16_shift_right"]
-def UInt16.shiftRight (a b : UInt16) : UInt16 := ⟨a.toBitVec >>> (mod b 16).toBitVec⟩
-def UInt16.lt (a b : UInt16) : Prop := a.toBitVec < b.toBitVec
-def UInt16.le (a b : UInt16) : Prop := a.toBitVec ≤ b.toBitVec
+def UInt16.shiftRight (a b : UInt16) : UInt16 := ⟨a.val >>> (modn b 16).val⟩
+def UInt16.lt (a b : UInt16) : Prop := a.val < b.val
+def UInt16.le (a b : UInt16) : Prop := a.val ≤ b.val
 
+instance UInt16.instOfNat : OfNat UInt16 n := ⟨UInt16.ofNat n⟩
 instance : Add UInt16       := ⟨UInt16.add⟩
 instance : Sub UInt16       := ⟨UInt16.sub⟩
 instance : Mul UInt16       := ⟨UInt16.mul⟩
 instance : Mod UInt16       := ⟨UInt16.mod⟩
-
-set_option linter.deprecated false in
 instance : HMod UInt16 Nat UInt16 := ⟨UInt16.modn⟩
-
 instance : Div UInt16       := ⟨UInt16.div⟩
 instance : LT UInt16        := ⟨UInt16.lt⟩
 instance : LE UInt16        := ⟨UInt16.le⟩
 
 @[extern "lean_uint16_complement"]
-def UInt16.complement (a : UInt16) : UInt16 := ⟨~~~a.toBitVec⟩
+def UInt16.complement (a:UInt16) : UInt16 := 0-(a+1)
 
 instance : Complement UInt16 := ⟨UInt16.complement⟩
 instance : AndOp UInt16     := ⟨UInt16.land⟩
@@ -119,53 +132,74 @@ instance : ShiftRight UInt16 := ⟨UInt16.shiftRight⟩
 set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint16_dec_lt"]
 def UInt16.decLt (a b : UInt16) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec < b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n < m))
 
 set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint16_dec_le"]
 def UInt16.decLe (a b : UInt16) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec ≤ b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n <= m))
 
 instance (a b : UInt16) : Decidable (a < b) := UInt16.decLt a b
 instance (a b : UInt16) : Decidable (a ≤ b) := UInt16.decLe a b
 instance : Max UInt16 := maxOfLe
 instance : Min UInt16 := minOfLe
 
+@[extern "lean_uint32_of_nat"]
+def UInt32.ofNat (n : @& Nat) : UInt32 := ⟨Fin.ofNat n⟩
+@[extern "lean_uint32_of_nat"]
+def UInt32.ofNat' (n : Nat) (h : n < UInt32.size) : UInt32 := ⟨⟨n, h⟩⟩
+/--
+Converts the given natural number to `UInt32`, but returns `2^32 - 1` for natural numbers `>= 2^32`.
+-/
+def UInt32.ofNatTruncate (n : Nat) : UInt32 :=
+  if h : n < UInt32.size then
+    UInt32.ofNat' n h
+  else
+    UInt32.ofNat' (UInt32.size - 1) (by decide)
+abbrev Nat.toUInt32 := UInt32.ofNat
 @[extern "lean_uint32_add"]
-def UInt32.add (a b : UInt32) : UInt32 := ⟨a.toBitVec + b.toBitVec⟩
+def UInt32.add (a b : UInt32) : UInt32 := ⟨a.val + b.val⟩
 @[extern "lean_uint32_sub"]
-def UInt32.sub (a b : UInt32) : UInt32 := ⟨a.toBitVec - b.toBitVec⟩
+def UInt32.sub (a b : UInt32) : UInt32 := ⟨a.val - b.val⟩
 @[extern "lean_uint32_mul"]
-def UInt32.mul (a b : UInt32) : UInt32 := ⟨a.toBitVec * b.toBitVec⟩
+def UInt32.mul (a b : UInt32) : UInt32 := ⟨a.val * b.val⟩
 @[extern "lean_uint32_div"]
-def UInt32.div (a b : UInt32) : UInt32 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
+def UInt32.div (a b : UInt32) : UInt32 := ⟨a.val / b.val⟩
 @[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⟩
+def UInt32.mod (a b : UInt32) : UInt32 := ⟨a.val % b.val⟩
+@[extern "lean_uint32_modn"]
+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⟩
+def UInt32.land (a b : UInt32) : UInt32 := ⟨Fin.land a.val b.val⟩
 @[extern "lean_uint32_lor"]
-def UInt32.lor (a b : UInt32) : UInt32 := ⟨a.toBitVec ||| b.toBitVec⟩
+def UInt32.lor (a b : UInt32) : UInt32 := ⟨Fin.lor a.val b.val⟩
 @[extern "lean_uint32_xor"]
-def UInt32.xor (a b : UInt32) : UInt32 := ⟨a.toBitVec ^^^ b.toBitVec⟩
+def UInt32.xor (a b : UInt32) : UInt32 := ⟨Fin.xor a.val b.val⟩
 @[extern "lean_uint32_shift_left"]
-def UInt32.shiftLeft (a b : UInt32) : UInt32 := ⟨a.toBitVec <<< (mod b 32).toBitVec⟩
+def UInt32.shiftLeft (a b : UInt32) : UInt32 := ⟨a.val <<< (modn b 32).val⟩
 @[extern "lean_uint32_shift_right"]
-def UInt32.shiftRight (a b : UInt32) : UInt32 := ⟨a.toBitVec >>> (mod b 32).toBitVec⟩
+def UInt32.shiftRight (a b : UInt32) : UInt32 := ⟨a.val >>> (modn b 32).val⟩
+@[extern "lean_uint32_to_uint8"]
+def UInt32.toUInt8 (a : UInt32) : UInt8 := a.toNat.toUInt8
+@[extern "lean_uint32_to_uint16"]
+def UInt32.toUInt16 (a : UInt32) : UInt16 := a.toNat.toUInt16
+@[extern "lean_uint8_to_uint32"]
+def UInt8.toUInt32 (a : UInt8) : UInt32 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
+@[extern "lean_uint16_to_uint32"]
+def UInt16.toUInt32 (a : UInt16) : UInt32 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
 
+instance UInt32.instOfNat : OfNat UInt32 n := ⟨UInt32.ofNat n⟩
 instance : Add UInt32       := ⟨UInt32.add⟩
 instance : Sub UInt32       := ⟨UInt32.sub⟩
 instance : Mul UInt32       := ⟨UInt32.mul⟩
 instance : Mod UInt32       := ⟨UInt32.mod⟩
-
-set_option linter.deprecated false in
 instance : HMod UInt32 Nat UInt32 := ⟨UInt32.modn⟩
-
 instance : Div UInt32       := ⟨UInt32.div⟩
 
 @[extern "lean_uint32_complement"]
-def UInt32.complement (a : UInt32) : UInt32 := ⟨~~~a.toBitVec⟩
+def UInt32.complement (a:UInt32) : UInt32 := 0-(a+1)
 
 instance : Complement UInt32 := ⟨UInt32.complement⟩
 instance : AndOp UInt32     := ⟨UInt32.land⟩
@@ -174,45 +208,60 @@ instance : Xor UInt32       := ⟨UInt32.xor⟩
 instance : ShiftLeft UInt32  := ⟨UInt32.shiftLeft⟩
 instance : ShiftRight UInt32 := ⟨UInt32.shiftRight⟩
 
+@[extern "lean_uint64_of_nat"]
+def UInt64.ofNat (n : @& Nat) : UInt64 := ⟨Fin.ofNat n⟩
+abbrev Nat.toUInt64 := UInt64.ofNat
+@[extern "lean_uint64_to_nat"]
+def UInt64.toNat (n : UInt64) : Nat := n.val.val
 @[extern "lean_uint64_add"]
-def UInt64.add (a b : UInt64) : UInt64 := ⟨a.toBitVec + b.toBitVec⟩
+def UInt64.add (a b : UInt64) : UInt64 := ⟨a.val + b.val⟩
 @[extern "lean_uint64_sub"]
-def UInt64.sub (a b : UInt64) : UInt64 := ⟨a.toBitVec - b.toBitVec⟩
+def UInt64.sub (a b : UInt64) : UInt64 := ⟨a.val - b.val⟩
 @[extern "lean_uint64_mul"]
-def UInt64.mul (a b : UInt64) : UInt64 := ⟨a.toBitVec * b.toBitVec⟩
+def UInt64.mul (a b : UInt64) : UInt64 := ⟨a.val * b.val⟩
 @[extern "lean_uint64_div"]
-def UInt64.div (a b : UInt64) : UInt64 := ⟨BitVec.udiv a.toBitVec b.toBitVec⟩
+def UInt64.div (a b : UInt64) : UInt64 := ⟨a.val / b.val⟩
 @[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⟩
+def UInt64.mod (a b : UInt64) : UInt64 := ⟨a.val % b.val⟩
+@[extern "lean_uint64_modn"]
+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⟩
+def UInt64.land (a b : UInt64) : UInt64 := ⟨Fin.land a.val b.val⟩
 @[extern "lean_uint64_lor"]
-def UInt64.lor (a b : UInt64) : UInt64 := ⟨a.toBitVec ||| b.toBitVec⟩
+def UInt64.lor (a b : UInt64) : UInt64 := ⟨Fin.lor a.val b.val⟩
 @[extern "lean_uint64_xor"]
-def UInt64.xor (a b : UInt64) : UInt64 := ⟨a.toBitVec ^^^ b.toBitVec⟩
+def UInt64.xor (a b : UInt64) : UInt64 := ⟨Fin.xor a.val b.val⟩
 @[extern "lean_uint64_shift_left"]
-def UInt64.shiftLeft (a b : UInt64) : UInt64 := ⟨a.toBitVec <<< (mod b 64).toBitVec⟩
+def UInt64.shiftLeft (a b : UInt64) : UInt64 := ⟨a.val <<< (modn b 64).val⟩
 @[extern "lean_uint64_shift_right"]
-def UInt64.shiftRight (a b : UInt64) : UInt64 := ⟨a.toBitVec >>> (mod b 64).toBitVec⟩
-def UInt64.lt (a b : UInt64) : Prop := a.toBitVec < b.toBitVec
-def UInt64.le (a b : UInt64) : Prop := a.toBitVec ≤ b.toBitVec
+def UInt64.shiftRight (a b : UInt64) : UInt64 := ⟨a.val >>> (modn b 64).val⟩
+def UInt64.lt (a b : UInt64) : Prop := a.val < b.val
+def UInt64.le (a b : UInt64) : Prop := a.val ≤ b.val
+@[extern "lean_uint64_to_uint8"]
+def UInt64.toUInt8 (a : UInt64) : UInt8 := a.toNat.toUInt8
+@[extern "lean_uint64_to_uint16"]
+def UInt64.toUInt16 (a : UInt64) : UInt16 := a.toNat.toUInt16
+@[extern "lean_uint64_to_uint32"]
+def UInt64.toUInt32 (a : UInt64) : UInt32 := a.toNat.toUInt32
+@[extern "lean_uint8_to_uint64"]
+def UInt8.toUInt64 (a : UInt8) : UInt64 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
+@[extern "lean_uint16_to_uint64"]
+def UInt16.toUInt64 (a : UInt16) : UInt64 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
+@[extern "lean_uint32_to_uint64"]
+def UInt32.toUInt64 (a : UInt32) : UInt64 := ⟨a.val, Nat.lt_trans a.1.2 (by decide)⟩
 
+instance UInt64.instOfNat : OfNat UInt64 n := ⟨UInt64.ofNat n⟩
 instance : Add UInt64       := ⟨UInt64.add⟩
 instance : Sub UInt64       := ⟨UInt64.sub⟩
 instance : Mul UInt64       := ⟨UInt64.mul⟩
 instance : Mod UInt64       := ⟨UInt64.mod⟩
-
-set_option linter.deprecated false in
 instance : HMod UInt64 Nat UInt64 := ⟨UInt64.modn⟩
-
 instance : Div UInt64       := ⟨UInt64.div⟩
 instance : LT UInt64        := ⟨UInt64.lt⟩
 instance : LE UInt64        := ⟨UInt64.le⟩
 
 @[extern "lean_uint64_complement"]
-def UInt64.complement (a : UInt64) : UInt64 := ⟨~~~a.toBitVec⟩
+def UInt64.complement (a:UInt64) : UInt64 := 0-(a+1)
 
 instance : Complement UInt64 := ⟨UInt64.complement⟩
 instance : AndOp UInt64     := ⟨UInt64.land⟩
@@ -224,52 +273,79 @@ instance : ShiftRight UInt64 := ⟨UInt64.shiftRight⟩
 @[extern "lean_bool_to_uint64"]
 def Bool.toUInt64 (b : Bool) : UInt64 := if b then 1 else 0
 
+set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint64_dec_lt"]
 def UInt64.decLt (a b : UInt64) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec < b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n < m))
 
+set_option bootstrap.genMatcherCode false in
 @[extern "lean_uint64_dec_le"]
 def UInt64.decLe (a b : UInt64) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec ≤ b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n <= m))
 
 instance (a b : UInt64) : Decidable (a < b) := UInt64.decLt a b
 instance (a b : UInt64) : Decidable (a ≤ b) := UInt64.decLe a b
 instance : Max UInt64 := maxOfLe
 instance : Min UInt64 := minOfLe
 
+-- This instance would interfere with the global instance `NeZero (n + 1)`,
+-- so we only enable it locally.
+@[local instance]
+private def instNeZeroUSizeSize : NeZero USize.size := ⟨add_one_ne_zero _⟩
+
+@[deprecated (since := "2024-09-16")]
+theorem usize_size_gt_zero : USize.size > 0 :=
+  Nat.zero_lt_succ ..
+
+@[extern "lean_usize_of_nat"]
+def USize.ofNat (n : @& Nat) : USize := ⟨Fin.ofNat'  _ n⟩
+abbrev Nat.toUSize := USize.ofNat
+@[extern "lean_usize_to_nat"]
+def USize.toNat (n : USize) : Nat := n.val.val
+@[extern "lean_usize_add"]
+def USize.add (a b : USize) : USize := ⟨a.val + b.val⟩
+@[extern "lean_usize_sub"]
+def USize.sub (a b : USize) : USize := ⟨a.val - b.val⟩
 @[extern "lean_usize_mul"]
-def USize.mul (a b : USize) : USize := ⟨a.toBitVec * b.toBitVec⟩
+def USize.mul (a b : USize) : USize := ⟨a.val * b.val⟩
 @[extern "lean_usize_div"]
-def USize.div (a b : USize) : USize := ⟨a.toBitVec / b.toBitVec⟩
+def USize.div (a b : USize) : USize := ⟨a.val / b.val⟩
 @[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⟩
+def USize.mod (a b : USize) : USize := ⟨a.val % b.val⟩
+@[extern "lean_usize_modn"]
+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⟩
+def USize.land (a b : USize) : USize := ⟨Fin.land a.val b.val⟩
 @[extern "lean_usize_lor"]
-def USize.lor (a b : USize) : USize := ⟨a.toBitVec ||| b.toBitVec⟩
+def USize.lor (a b : USize) : USize := ⟨Fin.lor a.val b.val⟩
 @[extern "lean_usize_xor"]
-def USize.xor (a b : USize) : USize := ⟨a.toBitVec ^^^ b.toBitVec⟩
+def USize.xor (a b : USize) : USize := ⟨Fin.xor a.val b.val⟩
 @[extern "lean_usize_shift_left"]
-def USize.shiftLeft (a b : USize) : USize := ⟨a.toBitVec <<< (mod b (USize.ofNat System.Platform.numBits)).toBitVec⟩
+def USize.shiftLeft (a b : USize) : USize := ⟨a.val <<< (modn b System.Platform.numBits).val⟩
 @[extern "lean_usize_shift_right"]
-def USize.shiftRight (a b : USize) : USize := ⟨a.toBitVec >>> (mod b (USize.ofNat System.Platform.numBits)).toBitVec⟩
+def USize.shiftRight (a b : USize) : USize := ⟨a.val >>> (modn b System.Platform.numBits).val⟩
 @[extern "lean_uint32_to_usize"]
-def UInt32.toUSize (a : UInt32) : USize := USize.ofNat32 a.toBitVec.toNat a.toBitVec.isLt
+def UInt32.toUSize (a : UInt32) : USize := USize.ofNat32 a.val a.1.2
 @[extern "lean_usize_to_uint32"]
 def USize.toUInt32 (a : USize) : UInt32 := a.toNat.toUInt32
 
+def USize.lt (a b : USize) : Prop := a.val < b.val
+def USize.le (a b : USize) : Prop := a.val ≤ b.val
+
+instance USize.instOfNat : OfNat USize n := ⟨USize.ofNat n⟩
+instance : Add USize       := ⟨USize.add⟩
+instance : Sub USize       := ⟨USize.sub⟩
 instance : Mul USize       := ⟨USize.mul⟩
 instance : Mod USize       := ⟨USize.mod⟩
-
-set_option linter.deprecated false in
 instance : HMod USize Nat USize := ⟨USize.modn⟩
-
 instance : Div USize       := ⟨USize.div⟩
+instance : LT USize        := ⟨USize.lt⟩
+instance : LE USize        := ⟨USize.le⟩
 
 @[extern "lean_usize_complement"]
-def USize.complement (a : USize) : USize := ⟨~~~a.toBitVec⟩
+def USize.complement (a:USize) : USize := 0-(a+1)
 
 instance : Complement USize := ⟨USize.complement⟩
 instance : AndOp USize      := ⟨USize.land⟩
@@ -278,5 +354,19 @@ instance : Xor USize        := ⟨USize.xor⟩
 instance : ShiftLeft USize  := ⟨USize.shiftLeft⟩
 instance : ShiftRight USize := ⟨USize.shiftRight⟩
 
+set_option bootstrap.genMatcherCode false in
+@[extern "lean_usize_dec_lt"]
+def USize.decLt (a b : USize) : Decidable (a < b) :=
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n < m))
+
+set_option bootstrap.genMatcherCode false in
+@[extern "lean_usize_dec_le"]
+def USize.decLe (a b : USize) : Decidable (a ≤ b) :=
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (n <= m))
+
+instance (a b : USize) : Decidable (a < b) := USize.decLt a b
+instance (a b : USize) : Decidable (a ≤ b) := USize.decLe a b
 instance : Max USize := maxOfLe
 instance : Min USize := minOfLe

src/Init/Data/UInt/BasicAux.lean

@@ -1,132 +0,0 @@
-/-
-Copyright (c) 2018 Microsoft Corporation. All rights reserved.
-Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Leonardo de Moura
--/
-prelude
-import Init.Data.Fin.Basic
-import Init.Data.BitVec.BasicAux
-
-/-!
-This module exists to provide the very basic `UInt8` etc. definitions required for
-`Init.Data.Char.Basic` and `Init.Data.Array.Basic`. These are very important as they are used in
-meta code that is then (transitively) used in `Init.Data.UInt.Basic` and `Init.Data.BitVec.Basic`.
-This file thus breaks the import cycle that would be created by this dependency.
--/
-
-open Nat
-
-def UInt8.val (x : UInt8) : Fin UInt8.size := x.toBitVec.toFin
-@[extern "lean_uint8_of_nat"]
-def UInt8.ofNat (n : @& Nat) : UInt8 := ⟨BitVec.ofNat 8 n⟩
-abbrev Nat.toUInt8 := UInt8.ofNat
-@[extern "lean_uint8_to_nat"]
-def UInt8.toNat (n : UInt8) : Nat := n.toBitVec.toNat
-
-instance UInt8.instOfNat : OfNat UInt8 n := ⟨UInt8.ofNat n⟩
-
-def UInt16.val (x : UInt16) : Fin UInt16.size := x.toBitVec.toFin
-@[extern "lean_uint16_of_nat"]
-def UInt16.ofNat (n : @& Nat) : UInt16 := ⟨BitVec.ofNat 16 n⟩
-abbrev Nat.toUInt16 := UInt16.ofNat
-@[extern "lean_uint16_to_nat"]
-def UInt16.toNat (n : UInt16) : Nat := n.toBitVec.toNat
-@[extern "lean_uint16_to_uint8"]
-def UInt16.toUInt8 (a : UInt16) : UInt8 := a.toNat.toUInt8
-@[extern "lean_uint8_to_uint16"]
-def UInt8.toUInt16 (a : UInt8) : UInt16 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-
-instance UInt16.instOfNat : OfNat UInt16 n := ⟨UInt16.ofNat n⟩
-
-def UInt32.val (x : UInt32) : Fin UInt32.size := x.toBitVec.toFin
-@[extern "lean_uint32_of_nat"]
-def UInt32.ofNat (n : @& Nat) : UInt32 := ⟨BitVec.ofNat 32 n⟩
-@[extern "lean_uint32_of_nat"]
-def UInt32.ofNat' (n : Nat) (h : n < UInt32.size) : UInt32 := ⟨BitVec.ofNatLt n h⟩
-/--
-Converts the given natural number to `UInt32`, but returns `2^32 - 1` for natural numbers `>= 2^32`.
--/
-def UInt32.ofNatTruncate (n : Nat) : UInt32 :=
-  if h : n < UInt32.size then
-    UInt32.ofNat' n h
-  else
-    UInt32.ofNat' (UInt32.size - 1) (by decide)
-abbrev Nat.toUInt32 := UInt32.ofNat
-@[extern "lean_uint32_to_uint8"]
-def UInt32.toUInt8 (a : UInt32) : UInt8 := a.toNat.toUInt8
-@[extern "lean_uint32_to_uint16"]
-def UInt32.toUInt16 (a : UInt32) : UInt16 := a.toNat.toUInt16
-@[extern "lean_uint8_to_uint32"]
-def UInt8.toUInt32 (a : UInt8) : UInt32 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-@[extern "lean_uint16_to_uint32"]
-def UInt16.toUInt32 (a : UInt16) : UInt32 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-
-instance UInt32.instOfNat : OfNat UInt32 n := ⟨UInt32.ofNat n⟩
-
-theorem UInt32.ofNat'_lt_of_lt {n m : Nat} (h1 : n < UInt32.size) (h2 : m < UInt32.size) :
-     n < m → UInt32.ofNat' n h1 < UInt32.ofNat m := by
-  simp only [(· < ·), BitVec.toNat, ofNat', BitVec.ofNatLt, ofNat, BitVec.ofNat, Fin.ofNat',
-    Nat.mod_eq_of_lt h2, imp_self]
-
-theorem UInt32.lt_ofNat'_of_lt {n m : Nat} (h1 : n < UInt32.size) (h2 : m < UInt32.size) :
-     m < n → UInt32.ofNat m < UInt32.ofNat' n h1  := by
-  simp only [(· < ·), BitVec.toNat, ofNat', BitVec.ofNatLt, ofNat, BitVec.ofNat, Fin.ofNat',
-    Nat.mod_eq_of_lt h2, imp_self]
-
-def UInt64.val (x : UInt64) : Fin UInt64.size := x.toBitVec.toFin
-@[extern "lean_uint64_of_nat"]
-def UInt64.ofNat (n : @& Nat) : UInt64 := ⟨BitVec.ofNat 64 n⟩
-abbrev Nat.toUInt64 := UInt64.ofNat
-@[extern "lean_uint64_to_nat"]
-def UInt64.toNat (n : UInt64) : Nat := n.toBitVec.toNat
-@[extern "lean_uint64_to_uint8"]
-def UInt64.toUInt8 (a : UInt64) : UInt8 := a.toNat.toUInt8
-@[extern "lean_uint64_to_uint16"]
-def UInt64.toUInt16 (a : UInt64) : UInt16 := a.toNat.toUInt16
-@[extern "lean_uint64_to_uint32"]
-def UInt64.toUInt32 (a : UInt64) : UInt32 := a.toNat.toUInt32
-@[extern "lean_uint8_to_uint64"]
-def UInt8.toUInt64 (a : UInt8) : UInt64 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-@[extern "lean_uint16_to_uint64"]
-def UInt16.toUInt64 (a : UInt16) : UInt64 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-@[extern "lean_uint32_to_uint64"]
-def UInt32.toUInt64 (a : UInt32) : UInt64 := ⟨⟨a.toNat, Nat.lt_trans a.toBitVec.isLt (by decide)⟩⟩
-
-instance UInt64.instOfNat : OfNat UInt64 n := ⟨UInt64.ofNat n⟩
-
-theorem usize_size_gt_zero : USize.size > 0 := by
-  cases usize_size_eq with
-  | inl h => rw [h]; decide
-  | inr h => rw [h]; decide
-
-def USize.val (x : USize) : Fin USize.size := x.toBitVec.toFin
-@[extern "lean_usize_of_nat"]
-def USize.ofNat (n : @& Nat) : USize := ⟨BitVec.ofNat _ n⟩
-abbrev Nat.toUSize := USize.ofNat
-@[extern "lean_usize_to_nat"]
-def USize.toNat (n : USize) : Nat := n.toBitVec.toNat
-@[extern "lean_usize_add"]
-def USize.add (a b : USize) : USize := ⟨a.toBitVec + b.toBitVec⟩
-@[extern "lean_usize_sub"]
-def USize.sub (a b : USize) : USize := ⟨a.toBitVec - b.toBitVec⟩
-
-def USize.lt (a b : USize) : Prop := a.toBitVec < b.toBitVec
-def USize.le (a b : USize) : Prop := a.toBitVec ≤ b.toBitVec
-
-instance USize.instOfNat : OfNat USize n := ⟨USize.ofNat n⟩
-
-instance : Add USize       := ⟨USize.add⟩
-instance : Sub USize       := ⟨USize.sub⟩
-instance : LT USize        := ⟨USize.lt⟩
-instance : LE USize        := ⟨USize.le⟩
-
-@[extern "lean_usize_dec_lt"]
-def USize.decLt (a b : USize) : Decidable (a < b) :=
-  inferInstanceAs (Decidable (a.toBitVec < b.toBitVec))
-
-@[extern "lean_usize_dec_le"]
-def USize.decLe (a b : USize) : Decidable (a ≤ b) :=
-  inferInstanceAs (Decidable (a.toBitVec ≤ b.toBitVec))
-
-instance (a b : USize) : Decidable (a < b) := USize.decLt a b
-instance (a b : USize) : Decidable (a ≤ b) := USize.decLe a b

src/Init/Data/UInt/Bitwise.lean

@@ -6,14 +6,13 @@ Authors: Markus Himmel
 prelude
 import Init.Data.UInt.Basic
 import Init.Data.Fin.Bitwise
-import Init.Data.BitVec.Lemmas
 
 set_option hygiene false in
 macro "declare_bitwise_uint_theorems" typeName:ident : command =>
 `(
 namespace $typeName
 
-@[simp] protected theorem and_toNat (a b : $typeName) : (a &&& b).toNat = a.toNat &&& b.toNat := BitVec.toNat_and ..
+@[simp] protected theorem and_toNat (a b : $typeName) : (a &&& b).toNat = a.toNat &&& b.toNat := Fin.and_val ..
 
 end $typeName
 )

src/Init/Data/UInt/Lemmas.lean

@@ -6,8 +6,6 @@ Authors: Leonardo de Moura
 prelude
 import Init.Data.UInt.Basic
 import Init.Data.Fin.Lemmas
-import Init.Data.BitVec.Lemmas
-import Init.Data.BitVec.Bitblast
 
 set_option hygiene false in
 macro "declare_uint_theorems" typeName:ident : command =>
@@ -19,111 +17,50 @@ instance : Inhabited $typeName where
 
 theorem zero_def : (0 : $typeName) = ⟨0⟩ := rfl
 theorem one_def : (1 : $typeName) = ⟨1⟩ := rfl
-theorem sub_def (a b : $typeName) : a - b = ⟨a.toBitVec - b.toBitVec⟩ := rfl
-theorem mul_def (a b : $typeName) : a * b = ⟨a.toBitVec * b.toBitVec⟩ := rfl
-theorem mod_def (a b : $typeName) : a % b = ⟨a.toBitVec % b.toBitVec⟩ := rfl
-theorem add_def (a b : $typeName) : a + b = ⟨a.toBitVec + b.toBitVec⟩ := rfl
+theorem sub_def (a b : $typeName) : a - b = ⟨a.val - b.val⟩ := rfl
+theorem mul_def (a b : $typeName) : a * b = ⟨a.val * b.val⟩ := rfl
+theorem mod_def (a b : $typeName) : a % b = ⟨a.val % b.val⟩ := rfl
+theorem add_def (a b : $typeName) : a + b = ⟨a.val + b.val⟩ := rfl
 
-@[simp] theorem mk_toBitVec_eq : ∀ (a : $typeName), mk a.toBitVec = a
+@[simp] theorem mk_val_eq : ∀ (a : $typeName), mk a.val = a
   | ⟨_, _⟩ => rfl
-
-theorem toBitVec_eq_of_lt {a : Nat} : a < size → (ofNat a).toBitVec.toNat = a :=
+theorem val_eq_of_lt {a : Nat} : a < size → ((ofNat a).val : Nat) = a :=
   Nat.mod_eq_of_lt
-
 theorem toNat_ofNat_of_lt {n : Nat} (h : n < size) : (ofNat n).toNat = n := by
-  rw [toNat, toBitVec_eq_of_lt h]
-
-theorem le_def {a b : $typeName} : a ≤ b ↔ a.toBitVec ≤ b.toBitVec := .rfl
-
-theorem lt_def {a b : $typeName} : a < b ↔ a.toBitVec < b.toBitVec := .rfl
-
-@[simp] protected theorem not_le {a b : $typeName} : ¬ a ≤ b ↔ b < a := by simp [le_def, lt_def]
-
-@[simp] protected theorem not_lt {a b : $typeName} : ¬ a < b ↔ b ≤ a := by simp [le_def, lt_def]
+  rw [toNat, val_eq_of_lt h]
 
+theorem le_def {a b : $typeName} : a ≤ b ↔ a.1 ≤ b.1 := .rfl
+theorem lt_def {a b : $typeName} : a < b ↔ a.1 < b.1 := .rfl
+theorem lt_iff_val_lt_val {a b : $typeName} : a < b ↔ a.val < b.val := .rfl
+@[simp] protected theorem not_le {a b : $typeName} : ¬ a ≤ b ↔ b < a := Fin.not_le
+@[simp] protected theorem not_lt {a b : $typeName} : ¬ a < b ↔ b ≤ a := Fin.not_lt
 @[simp] protected theorem le_refl (a : $typeName) : a ≤ a := by simp [le_def]
-
 @[simp] protected theorem lt_irrefl (a : $typeName) : ¬ a < a := by simp
-
-protected theorem le_trans {a b c : $typeName} : a ≤ b → b ≤ c → a ≤ c := BitVec.le_trans
-
-protected theorem lt_trans {a b c : $typeName} : a < b → b < c → a < c := BitVec.lt_trans
-
-protected theorem le_total (a b : $typeName) : a ≤ b ∨ b ≤ a := BitVec.le_total ..
-
-protected theorem lt_asymm {a b : $typeName} : a < b → ¬ b < a := BitVec.lt_asymm
-
-protected theorem toBitVec_eq_of_eq {a b : $typeName} (h : a = b) : a.toBitVec = b.toBitVec := h ▸ rfl
-
-protected theorem eq_of_toBitVec_eq {a b : $typeName} (h : a.toBitVec = b.toBitVec) : a = b := by
-  cases a; cases b; simp_all
-
-open $typeName (eq_of_toBitVec_eq) in
-protected theorem eq_of_val_eq {a b : $typeName} (h : a.val = b.val) : a = b := by
-  rcases a with ⟨⟨_⟩⟩; rcases b with ⟨⟨_⟩⟩; simp_all [val]
-
-open $typeName (toBitVec_eq_of_eq) in
-protected theorem ne_of_toBitVec_ne {a b : $typeName} (h : a.toBitVec ≠ b.toBitVec) : a ≠ b :=
-  fun h' => absurd (toBitVec_eq_of_eq h') h
-
-open $typeName (ne_of_toBitVec_ne) in
-protected theorem ne_of_lt {a b : $typeName} (h : a < b) : a ≠ b := by
-  apply ne_of_toBitVec_ne
-  apply BitVec.ne_of_lt
-  simpa [lt_def] using h
+protected theorem le_trans {a b c : $typeName} : a ≤ b → b ≤ c → a ≤ c := Fin.le_trans
+protected theorem lt_trans {a b c : $typeName} : a < b → b < c → a < c := Fin.lt_trans
+protected theorem le_total (a b : $typeName) : a ≤ b ∨ b ≤ a := Fin.le_total a.1 b.1
+protected theorem lt_asymm {a b : $typeName} (h : a < b) : ¬ b < a := Fin.lt_asymm h
+protected theorem val_eq_of_eq {a b : $typeName} (h : a = b) : a.val = b.val := h ▸ rfl
+protected theorem eq_of_val_eq {a b : $typeName} (h : a.val = b.val) : a = b := by cases a; cases b; simp at h; simp [h]
+open $typeName (val_eq_of_eq) in
+protected theorem ne_of_val_ne {a b : $typeName} (h : a.val ≠ b.val) : a ≠ b := fun h' => absurd (val_eq_of_eq h') h
+open $typeName (ne_of_val_ne) in
+protected theorem ne_of_lt {a b : $typeName} (h : a < b) : a ≠ b := ne_of_val_ne (Fin.ne_of_lt h)
 
 @[simp] protected theorem toNat_zero : (0 : $typeName).toNat = 0 := Nat.zero_mod _
-
-@[simp] protected theorem toNat_mod (a b : $typeName) : (a % b).toNat = a.toNat % b.toNat := BitVec.toNat_umod ..
-
-@[simp] protected theorem toNat_div (a b : $typeName) : (a / b).toNat = a.toNat / b.toNat := BitVec.toNat_udiv  ..
-
-@[simp] protected theorem toNat_sub_of_le (a b : $typeName) : b ≤ a → (a - b).toNat = a.toNat - b.toNat := BitVec.toNat_sub_of_le
-
-protected theorem toNat_lt_size (a : $typeName) : a.toNat < size := a.toBitVec.isLt
-
-open $typeName (toNat_mod toNat_lt_size) in
-protected theorem toNat_mod_lt {m : Nat} : ∀ (u : $typeName), m > 0 → toNat (u % ofNat m) < m := by
-  intro u h1
-  by_cases h2 : m < size
-  · rw [toNat_mod, toNat_ofNat_of_lt h2]
-    apply Nat.mod_lt _ h1
-  · apply Nat.lt_of_lt_of_le
-    · apply toNat_lt_size
-    · simpa using h2
-
-open $typeName (toNat_mod_lt) in
-set_option linter.deprecated false in
-@[deprecated toNat_mod_lt (since := "2024-09-24")]
-protected theorem modn_lt {m : Nat} : ∀ (u : $typeName), m > 0 → toNat (u % m) < m := by
-  intro u
-  simp only [(· % ·)]
-  simp only [gt_iff_lt, toNat, modn, Fin.modn_val, BitVec.natCast_eq_ofNat, BitVec.toNat_ofNat,
-    Nat.reducePow]
-  rw [Nat.mod_eq_of_lt]
-  · apply Nat.mod_lt
-  · apply Nat.lt_of_le_of_lt
-    · apply Nat.mod_le
-    · apply Fin.is_lt
-
-protected theorem mod_lt (a : $typeName) {b : $typeName} : 0 < b → a % b < b := by
-  simp only [lt_def, mod_def]
-  apply BitVec.umod_lt
-
+@[simp] protected theorem toNat_mod (a b : $typeName) : (a % b).toNat = a.toNat % b.toNat := Fin.mod_val ..
+@[simp] protected theorem toNat_div (a b : $typeName) : (a / b).toNat = a.toNat / b.toNat := Fin.div_val ..
+@[simp] protected theorem toNat_sub_of_le (a b : $typeName) : b ≤ a → (a - b).toNat = a.toNat - b.toNat := Fin.sub_val_of_le
+@[simp] protected theorem toNat_modn (a : $typeName) (b : Nat) : (a.modn b).toNat = a.toNat % b := Fin.modn_val ..
+protected theorem modn_lt {m : Nat} : ∀ (u : $typeName), m > 0 → toNat (u % m) < m
+  | ⟨u⟩, h => Fin.modn_lt u h
+open $typeName (modn_lt) in
+protected theorem mod_lt (a b : $typeName) (h : 0 < b) : a % b < b := modn_lt _ (by simp [lt_def] at h; exact h)
 protected theorem toNat.inj : ∀ {a b : $typeName}, a.toNat = b.toNat → a = b
   | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
-
+protected theorem toNat_lt_size (a : $typeName) : a.toNat < size := a.1.2
 @[simp] protected theorem ofNat_one : ofNat 1 = 1 := rfl
 
-@[simp]
-theorem val_ofNat (n : Nat) : val (no_index (OfNat.ofNat n)) = OfNat.ofNat n := rfl
-
-@[simp]
-theorem toBitVec_ofNat (n : Nat) : toBitVec (no_index (OfNat.ofNat n)) = BitVec.ofNat _ n := rfl
-
-@[simp]
-theorem mk_ofNat (n : Nat) : mk (BitVec.ofNat _ n) = OfNat.ofNat n := rfl
-
 end $typeName
 )
 
@@ -133,34 +70,27 @@ declare_uint_theorems UInt32
 declare_uint_theorems UInt64
 declare_uint_theorems USize
 
-theorem UInt32.toNat_lt_of_lt {n : UInt32} {m : Nat} (h : m < size) : n < ofNat m → n.toNat < m := by
-  simp [lt_def, BitVec.lt_def, UInt32.toNat, toBitVec_eq_of_lt h]
-
-theorem UInt32.lt_toNat_of_lt {n : UInt32} {m : Nat} (h : m < size) : ofNat m < n → m < n.toNat := by
-  simp [lt_def, BitVec.lt_def, UInt32.toNat, toBitVec_eq_of_lt h]
-
-theorem UInt32.toNat_le_of_le {n : UInt32} {m : Nat} (h : m < size) : n ≤ ofNat m → n.toNat ≤ m := by
-  simp [le_def, BitVec.le_def, UInt32.toNat, toBitVec_eq_of_lt h]
-
-theorem UInt32.le_toNat_of_le {n : UInt32} {m : Nat} (h : m < size) : ofNat m ≤ n → m ≤ n.toNat := by
-  simp [le_def, BitVec.le_def, UInt32.toNat, toBitVec_eq_of_lt h]
-
 @[deprecated (since := "2024-06-23")] protected abbrev UInt8.zero_toNat := @UInt8.toNat_zero
 @[deprecated (since := "2024-06-23")] protected abbrev UInt8.div_toNat := @UInt8.toNat_div
 @[deprecated (since := "2024-06-23")] protected abbrev UInt8.mod_toNat := @UInt8.toNat_mod
+@[deprecated (since := "2024-06-23")] protected abbrev UInt8.modn_toNat := @UInt8.toNat_modn
 
 @[deprecated (since := "2024-06-23")] protected abbrev UInt16.zero_toNat := @UInt16.toNat_zero
 @[deprecated (since := "2024-06-23")] protected abbrev UInt16.div_toNat := @UInt16.toNat_div
 @[deprecated (since := "2024-06-23")] protected abbrev UInt16.mod_toNat := @UInt16.toNat_mod
+@[deprecated (since := "2024-06-23")] protected abbrev UInt16.modn_toNat := @UInt16.toNat_modn
 
 @[deprecated (since := "2024-06-23")] protected abbrev UInt32.zero_toNat := @UInt32.toNat_zero
 @[deprecated (since := "2024-06-23")] protected abbrev UInt32.div_toNat := @UInt32.toNat_div
 @[deprecated (since := "2024-06-23")] protected abbrev UInt32.mod_toNat := @UInt32.toNat_mod
+@[deprecated (since := "2024-06-23")] protected abbrev UInt32.modn_toNat := @UInt32.toNat_modn
 
 @[deprecated (since := "2024-06-23")] protected abbrev UInt64.zero_toNat := @UInt64.toNat_zero
 @[deprecated (since := "2024-06-23")] protected abbrev UInt64.div_toNat := @UInt64.toNat_div
 @[deprecated (since := "2024-06-23")] protected abbrev UInt64.mod_toNat := @UInt64.toNat_mod
+@[deprecated (since := "2024-06-23")] protected abbrev UInt64.modn_toNat := @UInt64.toNat_modn
 
 @[deprecated (since := "2024-06-23")] protected abbrev USize.zero_toNat := @USize.toNat_zero
 @[deprecated (since := "2024-06-23")] protected abbrev USize.div_toNat := @USize.toNat_div
 @[deprecated (since := "2024-06-23")] protected abbrev USize.mod_toNat := @USize.toNat_mod
+@[deprecated (since := "2024-06-23")] protected abbrev USize.modn_toNat := @USize.toNat_modn

src/Init/Data/UInt/Log2.lean

@@ -7,16 +7,16 @@ prelude
 import Init.Data.Fin.Log2
 
 @[extern "lean_uint8_log2"]
-def UInt8.log2 (a : UInt8) : UInt8 := ⟨⟨Fin.log2 a.val⟩⟩
+def UInt8.log2 (a : UInt8) : UInt8 := ⟨Fin.log2 a.val⟩
 
 @[extern "lean_uint16_log2"]
-def UInt16.log2 (a : UInt16) : UInt16 := ⟨⟨Fin.log2 a.val⟩⟩
+def UInt16.log2 (a : UInt16) : UInt16 := ⟨Fin.log2 a.val⟩
 
 @[extern "lean_uint32_log2"]
-def UInt32.log2 (a : UInt32) : UInt32 := ⟨⟨Fin.log2 a.val⟩⟩
+def UInt32.log2 (a : UInt32) : UInt32 := ⟨Fin.log2 a.val⟩
 
 @[extern "lean_uint64_log2"]
-def UInt64.log2 (a : UInt64) : UInt64 := ⟨⟨Fin.log2 a.val⟩⟩
+def UInt64.log2 (a : UInt64) : UInt64 := ⟨Fin.log2 a.val⟩
 
 @[extern "lean_usize_log2"]
-def USize.log2 (a : USize) : USize := ⟨⟨Fin.log2 a.val⟩⟩
+def USize.log2 (a : USize) : USize := ⟨Fin.log2 a.val⟩

src/Init/GetElem.lean

@@ -144,26 +144,22 @@ instance (priority := low) [GetElem coll idx elem valid] [∀ xs i, Decidable (v
     LawfulGetElem coll idx elem valid where
 
 theorem getElem?_pos [GetElem? cont idx elem dom] [LawfulGetElem cont idx elem dom]
-    (c : cont) (i : idx) (h : dom c i) : c[i]? = some (c[i]'h) := by
-  have : Decidable (dom c i) := .isTrue h
+    (c : cont) (i : idx) (h : dom c i) [Decidable (dom c i)] : c[i]? = some (c[i]'h) := by
   rw [getElem?_def]
   exact dif_pos h
 
 theorem getElem?_neg [GetElem? cont idx elem dom] [LawfulGetElem cont idx elem dom]
-    (c : cont) (i : idx) (h : ¬dom c i) : c[i]? = none := by
-  have : Decidable (dom c i) := .isFalse h
+    (c : cont) (i : idx) (h : ¬dom c i) [Decidable (dom c i)] : c[i]? = none := by
   rw [getElem?_def]
   exact dif_neg h
 
 theorem getElem!_pos [GetElem? cont idx elem dom] [LawfulGetElem cont idx elem dom]
-    [Inhabited elem] (c : cont) (i : idx) (h : dom c i) :
+    [Inhabited elem] (c : cont) (i : idx) (h : dom c i) [Decidable (dom c i)] :
     c[i]! = c[i]'h := by
-  have : Decidable (dom c i) := .isTrue h
   simp [getElem!_def, getElem?_def, h]
 
 theorem getElem!_neg [GetElem? cont idx elem dom] [LawfulGetElem cont idx elem dom]
-    [Inhabited elem] (c : cont) (i : idx) (h : ¬dom c i) : c[i]! = default := by
-  have : Decidable (dom c i) := .isFalse h
+    [Inhabited elem] (c : cont) (i : idx) (h : ¬dom c i) [Decidable (dom c i)] : c[i]! = default := by
   simp [getElem!_def, getElem?_def, h]
 
 namespace Fin
@@ -207,17 +203,10 @@ instance : GetElem (List α) Nat α fun as i => i < as.length where
 
 @[deprecated (since := "2024-06-12")] abbrev cons_getElem_succ := @getElem_cons_succ
 
-@[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 getElem_cons_drop_succ_eq_drop {as : List α} {i : Nat} (h : i < as.length) :
-    as[i] :: as.drop (i+1) = as.drop i :=
+theorem get_drop_eq_drop (as : List α) (i : Nat) (h : i < as.length) : as[i] :: as.drop (i+1) = as.drop i :=
   match as, i with
   | _::_, 0   => rfl
-  | _::_, i+1 => getElem_cons_drop_succ_eq_drop (i := i) _
-
-@[deprecated (since := "2024-11-05")] abbrev get_drop_eq_drop := @getElem_cons_drop_succ_eq_drop
+  | _::_, i+1 => get_drop_eq_drop _ i _
 
 end List
 

src/Init/Meta.lean

@@ -629,9 +629,6 @@ def mkStrLit (val : String) (info := SourceInfo.none) : StrLit :=
 def mkNumLit (val : String) (info := SourceInfo.none) : NumLit :=
   mkLit numLitKind val info
 
-def mkNatLit (val : Nat) (info := SourceInfo.none) : NumLit :=
-  mkLit numLitKind (toString val) info
-
 def mkScientificLit (val : String) (info := SourceInfo.none) : TSyntax scientificLitKind :=
   mkLit scientificLitKind val info
 
@@ -1412,87 +1409,64 @@ namespace Parser
 
 namespace Tactic
 
-/--
-Extracts the items from a tactic configuration,
-either a `Lean.Parser.Tactic.optConfig`, `Lean.Parser.Tactic.config`, or these wrapped in null nodes.
--/
-partial def getConfigItems (c : Syntax) : TSyntaxArray ``configItem :=
-  if c.isOfKind nullKind then
-    c.getArgs.flatMap getConfigItems
-  else
-    match c with
-    | `(optConfig| $items:configItem*) => items
-    | `(config| (config := $_)) => #[⟨c⟩] -- handled by mkConfigItemViews
-    | _ => #[]
-
-def mkOptConfig (items : TSyntaxArray ``configItem) : TSyntax ``optConfig :=
-  ⟨Syntax.node1 .none ``optConfig (mkNullNode items)⟩
-
-/--
-Appends two tactic configurations.
-The configurations can be `Lean.Parser.Tactic.optConfig`, `Lean.Parser.Tactic.config`,
-or these wrapped in null nodes (for example because the syntax is `(config)?`).
--/
-def appendConfig (cfg cfg' : Syntax) : TSyntax ``optConfig :=
-  mkOptConfig <| getConfigItems cfg ++ getConfigItems cfg'
-
-/-- `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 loc:(location)? : tactic => do
-  `(tactic| rw $[$(getConfigItems c)]* (transparency := .default) $s:rwRuleSeq $(loc)?)
+macro "erw" s:rwRuleSeq loc:(location)? : tactic =>
+  `(tactic| rw (config := { transparency := .default }) $s $(loc)?)
 
 syntax simpAllKind := atomic(" (" &"all") " := " &"true" ")"
 syntax dsimpKind   := atomic(" (" &"dsimp") " := " &"true" ")"
 
 macro (name := declareSimpLikeTactic) doc?:(docComment)?
     "declare_simp_like_tactic" opt:((simpAllKind <|> dsimpKind)?)
-    ppSpace tacName:ident ppSpace tacToken:str ppSpace cfg:optConfig : command => do
+    ppSpace tacName:ident ppSpace tacToken:str ppSpace updateCfg:term : command => do
   let (kind, tkn, stx) ←
     if opt.raw.isNone then
-      pure (← `(``simp), ← `("simp"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str optConfig (discharger)? (&" only")? (" [" (simpStar <|> simpErase <|> simpLemma),* "]")? (location)? : tactic))
+      pure (← `(``simp), ← `("simp"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str (config)? (discharger)? (&" only")? (" [" (simpStar <|> simpErase <|> simpLemma),* "]")? (location)? : tactic))
     else if opt.raw[0].getKind == ``simpAllKind then
-      pure (← `(``simpAll), ← `("simp_all"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str optConfig (discharger)? (&" only")? (" [" (simpErase <|> simpLemma),* "]")? : tactic))
+      pure (← `(``simpAll), ← `("simp_all"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str (config)? (discharger)? (&" only")? (" [" (simpErase <|> simpLemma),* "]")? : tactic))
     else
-      pure (← `(``dsimp), ← `("dsimp"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str optConfig (discharger)? (&" only")? (" [" (simpErase <|> simpLemma),* "]")? (location)? : tactic))
+      pure (← `(``dsimp), ← `("dsimp"), ← `($[$doc?:docComment]? syntax (name := $tacName) $tacToken:str (config)? (discharger)? (&" only")? (" [" (simpErase <|> simpLemma),* "]")? (location)? : tactic))
   `($stx:command
     @[macro $tacName] def expandSimp : Macro := fun s => do
-      let cfg ← `(optConfig| $cfg)
+      let c ← match s[1][0] with
+        | `(config| (config := $$c)) => `(config| (config := $updateCfg $$c))
+        | _ => `(config| (config := $updateCfg {}))
       let s := s.setKind $kind
       let s := s.setArg 0 (mkAtomFrom s[0] $tkn (canonical := true))
-      let s := s.setArg 1 (appendConfig s[1] cfg)
-      let s := s.mkSynthetic
-      return s)
+      let r := s.setArg 1 (mkNullNode #[c])
+      return r)
 
 /-- `simp!` is shorthand for `simp` with `autoUnfold := true`.
 This will rewrite with all equation lemmas, which can be used to
 partially evaluate many definitions. -/
-declare_simp_like_tactic simpAutoUnfold "simp! " (autoUnfold := true)
+declare_simp_like_tactic simpAutoUnfold "simp! " fun (c : Lean.Meta.Simp.Config) => { c with autoUnfold := true }
 
 /-- `simp_arith` is shorthand for `simp` with `arith := true` and `decide := true`.
 This enables the use of normalization by linear arithmetic. -/
-declare_simp_like_tactic simpArith "simp_arith " (arith := true) (decide := true)
+declare_simp_like_tactic simpArith "simp_arith " fun (c : Lean.Meta.Simp.Config) => { c with arith := true, decide := true }
 
 /-- `simp_arith!` is shorthand for `simp_arith` with `autoUnfold := true`.
 This will rewrite with all equation lemmas, which can be used to
 partially evaluate many definitions. -/
-declare_simp_like_tactic simpArithAutoUnfold "simp_arith! " (arith := true) (autoUnfold := true) (decide := true)
+declare_simp_like_tactic simpArithAutoUnfold "simp_arith! " fun (c : Lean.Meta.Simp.Config) => { c with arith := true, autoUnfold := true, decide := true }
 
 /-- `simp_all!` is shorthand for `simp_all` with `autoUnfold := true`.
 This will rewrite with all equation lemmas, which can be used to
 partially evaluate many definitions. -/
-declare_simp_like_tactic (all := true) simpAllAutoUnfold "simp_all! " (autoUnfold := true)
+declare_simp_like_tactic (all := true) simpAllAutoUnfold "simp_all! " fun (c : Lean.Meta.Simp.ConfigCtx) => { c with autoUnfold := true }
 
 /-- `simp_all_arith` combines the effects of `simp_all` and `simp_arith`. -/
-declare_simp_like_tactic (all := true) simpAllArith "simp_all_arith " (arith := true) (decide := true)
+declare_simp_like_tactic (all := true) simpAllArith "simp_all_arith " fun (c : Lean.Meta.Simp.ConfigCtx) => { c with arith := true, decide := true }
 
 /-- `simp_all_arith!` combines the effects of `simp_all`, `simp_arith` and `simp!`. -/
-declare_simp_like_tactic (all := true) simpAllArithAutoUnfold "simp_all_arith! " (arith := true) (autoUnfold := true) (decide := true)
+declare_simp_like_tactic (all := true) simpAllArithAutoUnfold "simp_all_arith! " fun (c : Lean.Meta.Simp.ConfigCtx) => { c with arith := true, autoUnfold := true, decide := true }
 
 /-- `dsimp!` is shorthand for `dsimp` with `autoUnfold := true`.
 This will rewrite with all equation lemmas, which can be used to
 partially evaluate many definitions. -/
-declare_simp_like_tactic (dsimp := true) dsimpAutoUnfold "dsimp! " (autoUnfold := true)
+declare_simp_like_tactic (dsimp := true) dsimpAutoUnfold "dsimp! " fun (c : Lean.Meta.DSimp.Config) => { c with autoUnfold := true }
 
 end Tactic
 

src/Init/MetaTypes.lean

@@ -224,7 +224,11 @@ structure Config where
   -/
   index             : Bool := true
   /--
-  This option does not have any effect (yet).
+  When `true` (default: `true`), `simp` will **not** create a proof for a rewriting rule associated
+  with an `rfl`-theorem.
+  Rewriting rules are provided by users by annotating theorems with the attribute `@[simp]`.
+  If the proof of the theorem is just `rfl` (reflexivity), and `implicitDefEqProofs := true`, `simp`
+  will **not** create a proof term which is an application of the annotated theorem.
   -/
   implicitDefEqProofs : Bool := true
   deriving Inhabited, BEq

src/Init/Notation.lean

@@ -341,19 +341,16 @@ macro_rules | `($x == $y) => `(binrel_no_prop% BEq.beq $x $y)
 notation:50 a:50 " ∉ " b:50 => ¬ (a ∈ b)
 
 @[inherit_doc] infixr:67 " :: " => List.cons
-@[inherit_doc] infixr:100 " <$> " => Functor.map
-@[inherit_doc] infixl:55  " >>= " => Bind.bind
-@[inherit_doc HOrElse.hOrElse]   syntax:20 term:21 " <|> " term:20 : term
+@[inherit_doc HOrElse.hOrElse] syntax:20 term:21 " <|> " term:20 : term
 @[inherit_doc HAndThen.hAndThen] syntax:60 term:61 " >> " term:60 : term
-@[inherit_doc Seq.seq]           syntax:60 term:60 " <*> " term:61 : term
-@[inherit_doc SeqLeft.seqLeft]   syntax:60 term:60 " <* " term:61 : term
-@[inherit_doc SeqRight.seqRight] syntax:60 term:60 " *> " term:61 : term
+@[inherit_doc] infixl:55  " >>= " => Bind.bind
+@[inherit_doc] notation:60 a:60 " <*> " b:61 => Seq.seq a fun _ : Unit => b
+@[inherit_doc] notation:60 a:60 " <* " b:61 => SeqLeft.seqLeft a fun _ : Unit => b
+@[inherit_doc] notation:60 a:60 " *> " b:61 => SeqRight.seqRight a fun _ : Unit => b
+@[inherit_doc] infixr:100 " <$> " => Functor.map
 
 macro_rules | `($x <|> $y) => `(binop_lazy% HOrElse.hOrElse $x $y)
 macro_rules | `($x >> $y)  => `(binop_lazy% HAndThen.hAndThen $x $y)
-macro_rules | `($x <*> $y) => `(Seq.seq $x fun _ : Unit => $y)
-macro_rules | `($x <* $y)  => `(SeqLeft.seqLeft $x fun _ : Unit => $y)
-macro_rules | `($x *> $y)  => `(SeqRight.seqRight $x fun _ : Unit => $y)
 
 namespace Lean
 

src/Init/NotationExtra.lean

@@ -10,7 +10,6 @@ import Init.Data.ToString.Basic
 import Init.Data.Array.Subarray
 import Init.Conv
 import Init.Meta
-import Init.While
 
 namespace Lean
 
@@ -169,9 +168,9 @@ end Lean
   | _                => throw ()
 
 @[app_unexpander sorryAx] def unexpandSorryAx : Lean.PrettyPrinter.Unexpander
-  | `($(_) $_)    => `(sorry)
-  | `($(_) $_ $_) => `(sorry)
-  | _             => throw ()
+  | `($(_) _)   => `(sorry)
+  | `($(_) _ _) => `(sorry)
+  | _           => throw ()
 
 @[app_unexpander Eq.ndrec] def unexpandEqNDRec : Lean.PrettyPrinter.Unexpander
   | `($(_) $m $h) => `($h ▸ $m)
@@ -345,6 +344,42 @@ syntax (name := solveTactic) "solve" withPosition((ppDedent(ppLine) colGe "| " t
 macro_rules
   | `(tactic| solve $[| $ts]* ) => `(tactic| focus first $[| ($ts); done]*)
 
+/-! # `repeat` and `while` notation -/
+
+inductive Loop where
+  | mk
+
+@[inline]
+partial def Loop.forIn {β : Type u} {m : Type u → Type v} [Monad m] (_ : Loop) (init : β) (f : Unit → β → m (ForInStep β)) : m β :=
+  let rec @[specialize] loop (b : β) : m β := do
+    match ← f () b with
+      | ForInStep.done b  => pure b
+      | ForInStep.yield b => loop b
+  loop init
+
+instance : ForIn m Loop Unit where
+  forIn := Loop.forIn
+
+syntax "repeat " doSeq : doElem
+
+macro_rules
+  | `(doElem| repeat $seq) => `(doElem| for _ in Loop.mk do $seq)
+
+syntax "while " ident " : " termBeforeDo " do " doSeq : doElem
+
+macro_rules
+  | `(doElem| while $h : $cond do $seq) => `(doElem| repeat if $h : $cond then $seq else break)
+
+syntax "while " termBeforeDo " do " doSeq : doElem
+
+macro_rules
+  | `(doElem| while $cond do $seq) => `(doElem| repeat if $cond then $seq else break)
+
+syntax "repeat " doSeq ppDedent(ppLine) "until " term : doElem
+
+macro_rules
+  | `(doElem| repeat $seq until $cond) => `(doElem| repeat do $seq:doSeq; if $cond then break)
+
 macro:50 e:term:51 " matches " p:sepBy1(term:51, " | ") : term =>
   `(((match $e:term with | $[$p:term]|* => true | _ => false) : Bool))
 

src/Init/Prelude.lean

@@ -1592,6 +1592,9 @@ def Nat.beq : (@& Nat) → (@& Nat) → Bool
   | succ _, zero   => false
   | succ n, succ m => beq n m
 
+instance : BEq Nat where
+  beq := Nat.beq
+
 theorem Nat.eq_of_beq_eq_true : {n m : Nat} → Eq (beq n m) true → Eq n m
   | zero,   zero,   _ => rfl
   | zero,   succ _, h => Bool.noConfusion h
@@ -1866,52 +1869,6 @@ instance {n} : LE (Fin n) where
 instance Fin.decLt {n} (a b : Fin n) : Decidable (LT.lt a b) := Nat.decLt ..
 instance Fin.decLe {n} (a b : Fin n) : Decidable (LE.le a b) := Nat.decLe ..
 
-/--
-A bitvector of the specified width.
-
-This is represented as the underlying `Nat` number in both the runtime
-and the kernel, inheriting all the special support for `Nat`.
--/
-structure BitVec (w : Nat) where
-  /-- Construct a `BitVec w` from a number less than `2^w`.
-  O(1), because we use `Fin` as the internal representation of a bitvector. -/
-  ofFin ::
-  /-- Interpret a bitvector as a number less than `2^w`.
-  O(1), because we use `Fin` as the internal representation of a bitvector. -/
-  toFin : Fin (hPow 2 w)
-
-/--
-Bitvectors have decidable equality. This should be used via the instance `DecidableEq (BitVec n)`.
--/
--- We manually derive the `DecidableEq` instances for `BitVec` because
--- we want to have builtin support for bit-vector literals, and we
--- need a name for this function to implement `canUnfoldAtMatcher` at `WHNF.lean`.
-def BitVec.decEq (x y : BitVec n) : Decidable (Eq x y) :=
-  match x, y with
-  | ⟨n⟩, ⟨m⟩ =>
-    dite (Eq n m)
-      (fun h => isTrue (h ▸ rfl))
-      (fun h => isFalse (fun h' => BitVec.noConfusion h' (fun h' => absurd h' h)))
-
-instance : DecidableEq (BitVec n) := BitVec.decEq
-
-/-- The `BitVec` with value `i`, given a proof that `i < 2^n`. -/
-@[match_pattern]
-protected def BitVec.ofNatLt {n : Nat} (i : Nat) (p : LT.lt i (hPow 2 n)) : BitVec n where
-  toFin := ⟨i, p⟩
-
-/-- Given a bitvector `x`, return the underlying `Nat`. This is O(1) because `BitVec` is a
-(zero-cost) wrapper around a `Nat`. -/
-protected def BitVec.toNat (x : BitVec n) : Nat := x.toFin.val
-
-instance : LT (BitVec n) where lt := (LT.lt ·.toNat ·.toNat)
-instance (x y : BitVec n) : Decidable (LT.lt x y) :=
-  inferInstanceAs (Decidable (LT.lt x.toNat y.toNat))
-
-instance : LE (BitVec n) where le := (LE.le ·.toNat ·.toNat)
-instance (x y : BitVec n) : Decidable (LE.le x y) :=
-  inferInstanceAs (Decidable (LE.le x.toNat y.toNat))
-
 /-- The size of type `UInt8`, that is, `2^8 = 256`. -/
 abbrev UInt8.size : Nat := 256
 
@@ -1920,12 +1877,12 @@ The type of unsigned 8-bit integers. This type has special support in the
 compiler to make it actually 8 bits rather than wrapping a `Nat`.
 -/
 structure UInt8 where
-  /-- Unpack a `UInt8` as a `BitVec 8`.
+  /-- Unpack a `UInt8` as a `Nat` less than `2^8`.
   This function is overridden with a native implementation. -/
-  toBitVec : BitVec 8
+  val : Fin UInt8.size
 
 attribute [extern "lean_uint8_of_nat_mk"] UInt8.mk
-attribute [extern "lean_uint8_to_nat"] UInt8.toBitVec
+attribute [extern "lean_uint8_to_nat"] UInt8.val
 
 /--
 Pack a `Nat` less than `2^8` into a `UInt8`.
@@ -1933,7 +1890,7 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_uint8_of_nat"]
 def UInt8.ofNatCore (n : @& Nat) (h : LT.lt n UInt8.size) : UInt8 where
-  toBitVec := BitVec.ofNatLt n h
+  val := { val := n, isLt := h }
 
 set_option bootstrap.genMatcherCode false in
 /--
@@ -1944,9 +1901,7 @@ This function is overridden with a native implementation.
 def UInt8.decEq (a b : UInt8) : Decidable (Eq a b) :=
   match a, b with
   | ⟨n⟩, ⟨m⟩ =>
-    dite (Eq n m)
-      (fun h => isTrue (h ▸ rfl))
-      (fun h => isFalse (fun h' => UInt8.noConfusion h' (fun h' => absurd h' h)))
+    dite (Eq n m) (fun h => isTrue (h ▸ rfl)) (fun h => isFalse (fun h' => UInt8.noConfusion h' (fun h' => absurd h' h)))
 
 instance : DecidableEq UInt8 := UInt8.decEq
 
@@ -1961,12 +1916,12 @@ The type of unsigned 16-bit integers. This type has special support in the
 compiler to make it actually 16 bits rather than wrapping a `Nat`.
 -/
 structure UInt16 where
-  /-- Unpack a `UInt16` as a `BitVec 16`.
+  /-- Unpack a `UInt16` as a `Nat` less than `2^16`.
   This function is overridden with a native implementation. -/
-  toBitVec : BitVec 16
+  val : Fin UInt16.size
 
 attribute [extern "lean_uint16_of_nat_mk"] UInt16.mk
-attribute [extern "lean_uint16_to_nat"] UInt16.toBitVec
+attribute [extern "lean_uint16_to_nat"] UInt16.val
 
 /--
 Pack a `Nat` less than `2^16` into a `UInt16`.
@@ -1974,7 +1929,7 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_uint16_of_nat"]
 def UInt16.ofNatCore (n : @& Nat) (h : LT.lt n UInt16.size) : UInt16 where
-  toBitVec := BitVec.ofNatLt n h
+  val := { val := n, isLt := h }
 
 set_option bootstrap.genMatcherCode false in
 /--
@@ -1985,9 +1940,7 @@ This function is overridden with a native implementation.
 def UInt16.decEq (a b : UInt16) : Decidable (Eq a b) :=
   match a, b with
   | ⟨n⟩, ⟨m⟩ =>
-    dite (Eq n m)
-      (fun h => isTrue (h ▸ rfl))
-      (fun h => isFalse (fun h' => UInt16.noConfusion h' (fun h' => absurd h' h)))
+    dite (Eq n m) (fun h => isTrue (h ▸ rfl)) (fun h => isFalse (fun h' => UInt16.noConfusion h' (fun h' => absurd h' h)))
 
 instance : DecidableEq UInt16 := UInt16.decEq
 
@@ -2002,12 +1955,12 @@ The type of unsigned 32-bit integers. This type has special support in the
 compiler to make it actually 32 bits rather than wrapping a `Nat`.
 -/
 structure UInt32 where
-  /-- Unpack a `UInt32` as a `BitVec 32.
+  /-- Unpack a `UInt32` as a `Nat` less than `2^32`.
   This function is overridden with a native implementation. -/
-  toBitVec : BitVec 32
+  val : Fin UInt32.size
 
 attribute [extern "lean_uint32_of_nat_mk"] UInt32.mk
-attribute [extern "lean_uint32_to_nat"] UInt32.toBitVec
+attribute [extern "lean_uint32_to_nat"] UInt32.val
 
 /--
 Pack a `Nat` less than `2^32` into a `UInt32`.
@@ -2015,14 +1968,14 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_uint32_of_nat"]
 def UInt32.ofNatCore (n : @& Nat) (h : LT.lt n UInt32.size) : UInt32 where
-  toBitVec := BitVec.ofNatLt n h
+  val := { val := n, isLt := h }
 
 /--
 Unpack a `UInt32` as a `Nat`.
 This function is overridden with a native implementation.
 -/
 @[extern "lean_uint32_to_nat"]
-def UInt32.toNat (n : UInt32) : Nat := n.toBitVec.toNat
+def UInt32.toNat (n : UInt32) : Nat := n.val.val
 
 set_option bootstrap.genMatcherCode false in
 /--
@@ -2041,26 +1994,30 @@ instance : Inhabited UInt32 where
   default := UInt32.ofNatCore 0 (by decide)
 
 instance : LT UInt32 where
-  lt a b := LT.lt a.toBitVec b.toBitVec
+  lt a b := LT.lt a.val b.val
 
 instance : LE UInt32 where
-  le a b := LE.le a.toBitVec b.toBitVec
+  le a b := LE.le a.val b.val
 
+set_option bootstrap.genMatcherCode false in
 /--
 Decides less-equal on `UInt32`.
 This function is overridden with a native implementation.
 -/
 @[extern "lean_uint32_dec_lt"]
 def UInt32.decLt (a b : UInt32) : Decidable (LT.lt a b) :=
-  inferInstanceAs (Decidable (LT.lt a.toBitVec b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (LT.lt n m))
 
+set_option bootstrap.genMatcherCode false in
 /--
 Decides less-than on `UInt32`.
 This function is overridden with a native implementation.
 -/
 @[extern "lean_uint32_dec_le"]
 def UInt32.decLe (a b : UInt32) : Decidable (LE.le a b) :=
-  inferInstanceAs (Decidable (LE.le a.toBitVec b.toBitVec))
+  match a, b with
+  | ⟨n⟩, ⟨m⟩ => inferInstanceAs (Decidable (LE.le n m))
 
 instance (a b : UInt32) : Decidable (LT.lt a b) := UInt32.decLt a b
 instance (a b : UInt32) : Decidable (LE.le a b) := UInt32.decLe a b
@@ -2074,12 +2031,12 @@ The type of unsigned 64-bit integers. This type has special support in the
 compiler to make it actually 64 bits rather than wrapping a `Nat`.
 -/
 structure UInt64 where
-  /-- Unpack a `UInt64` as a `BitVec 64`.
+  /-- Unpack a `UInt64` as a `Nat` less than `2^64`.
   This function is overridden with a native implementation. -/
-  toBitVec: BitVec 64
+  val : Fin UInt64.size
 
 attribute [extern "lean_uint64_of_nat_mk"] UInt64.mk
-attribute [extern "lean_uint64_to_nat"] UInt64.toBitVec
+attribute [extern "lean_uint64_to_nat"] UInt64.val
 
 /--
 Pack a `Nat` less than `2^64` into a `UInt64`.
@@ -2087,7 +2044,7 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_uint64_of_nat"]
 def UInt64.ofNatCore (n : @& Nat) (h : LT.lt n UInt64.size) : UInt64 where
-  toBitVec := BitVec.ofNatLt n h
+  val := { val := n, isLt := h }
 
 set_option bootstrap.genMatcherCode false in
 /--
@@ -2098,20 +2055,36 @@ This function is overridden with a native implementation.
 def UInt64.decEq (a b : UInt64) : Decidable (Eq a b) :=
   match a, b with
   | ⟨n⟩, ⟨m⟩ =>
-    dite (Eq n m)
-      (fun h => isTrue (h ▸ rfl))
-      (fun h => isFalse (fun h' => UInt64.noConfusion h' (fun h' => absurd h' h)))
+    dite (Eq n m) (fun h => isTrue (h ▸ rfl)) (fun h => isFalse (fun h' => UInt64.noConfusion h' (fun h' => absurd h' h)))
 
 instance : DecidableEq UInt64 := UInt64.decEq
 
 instance : Inhabited UInt64 where
   default := UInt64.ofNatCore 0 (by decide)
 
-/-- The size of type `USize`, that is, `2^System.Platform.numBits`. -/
-abbrev USize.size : Nat := (hPow 2 System.Platform.numBits)
+/--
+The size of type `USize`, that is, `2^System.Platform.numBits`, which may
+be either `2^32` or `2^64` depending on the platform's architecture.
+
+Remark: we define `USize.size` using `(2^numBits - 1) + 1` to ensure the
+Lean unifier can solve constraints such as `?m + 1 = USize.size`. Recall that
+`numBits` does not reduce to a numeral in the Lean kernel since it is platform
+specific. Without this trick, the following definition would be rejected by the
+Lean type checker.
+```
+def one: Fin USize.size := 1
+```
+Because Lean would fail to synthesize instance `OfNat (Fin USize.size) 1`.
+Recall that the `OfNat` instance for `Fin` is
+```
+instance : OfNat (Fin (n+1)) i where
+  ofNat := Fin.ofNat i
+```
+-/
+abbrev USize.size : Nat := hAdd (hSub (hPow 2 System.Platform.numBits) 1) 1
 
 theorem usize_size_eq : Or (Eq USize.size 4294967296) (Eq USize.size 18446744073709551616) :=
-  show Or (Eq (hPow 2 System.Platform.numBits) 4294967296) (Eq (hPow 2 System.Platform.numBits) 18446744073709551616) from
+  show Or (Eq (Nat.succ (Nat.sub (hPow 2 System.Platform.numBits) 1)) 4294967296) (Eq (Nat.succ (Nat.sub (hPow 2 System.Platform.numBits) 1)) 18446744073709551616) from
   match System.Platform.numBits, System.Platform.numBits_eq with
   | _, Or.inl rfl => Or.inl (by decide)
   | _, Or.inr rfl => Or.inr (by decide)
@@ -2124,20 +2097,21 @@ For example, if running on a 32-bit machine, USize is equivalent to UInt32.
 Or on a 64-bit machine, UInt64.
 -/
 structure USize where
-  /-- Unpack a `USize` as a `BitVec System.Platform.numBits`.
+  /-- Unpack a `USize` as a `Nat` less than `USize.size`.
   This function is overridden with a native implementation. -/
-  toBitVec : BitVec System.Platform.numBits
+  val : Fin USize.size
 
 attribute [extern "lean_usize_of_nat_mk"] USize.mk
-attribute [extern "lean_usize_to_nat"] USize.toBitVec
+attribute [extern "lean_usize_to_nat"] USize.val
 
 /--
 Pack a `Nat` less than `USize.size` into a `USize`.
 This function is overridden with a native implementation.
 -/
 @[extern "lean_usize_of_nat"]
-def USize.ofNatCore (n : @& Nat) (h : LT.lt n USize.size) : USize where
-  toBitVec := BitVec.ofNatLt n h
+def USize.ofNatCore (n : @& Nat) (h : LT.lt n USize.size) : USize := {
+  val := { val := n, isLt := h }
+}
 
 set_option bootstrap.genMatcherCode false in
 /--
@@ -2148,9 +2122,7 @@ This function is overridden with a native implementation.
 def USize.decEq (a b : USize) : Decidable (Eq a b) :=
   match a, b with
   | ⟨n⟩, ⟨m⟩ =>
-    dite (Eq n m)
-      (fun h => isTrue (h ▸ rfl))
-      (fun h => isFalse (fun h' => USize.noConfusion h' (fun h' => absurd h' h)))
+    dite (Eq n m) (fun h =>isTrue (h ▸ rfl)) (fun h => isFalse (fun h' => USize.noConfusion h' (fun h' => absurd h' h)))
 
 instance : DecidableEq USize := USize.decEq
 
@@ -2166,12 +2138,12 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_usize_of_nat"]
 def USize.ofNat32 (n : @& Nat) (h : LT.lt n 4294967296) : USize where
-  toBitVec :=
-    BitVec.ofNatLt n (
-      match System.Platform.numBits, System.Platform.numBits_eq with
+  val := {
+    val  := n
+    isLt := match USize.size, usize_size_eq with
       | _, Or.inl rfl => h
       | _, Or.inr rfl => Nat.lt_trans h (by decide)
-    )
+  }
 
 /--
 A `Nat` denotes a valid unicode codepoint if it is less than `0x110000`, and
@@ -2206,7 +2178,7 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_uint32_of_nat"]
 def Char.ofNatAux (n : @& Nat) (h : n.isValidChar) : Char :=
-  { val := ⟨BitVec.ofNatLt n (isValidChar_UInt32 h)⟩, valid := h }
+  { val := ⟨{ val := n, isLt := isValidChar_UInt32 h }⟩, valid := h }
 
 /--
 Convert a `Nat` into a `Char`. If the `Nat` does not encode a valid unicode scalar value,
@@ -2216,7 +2188,7 @@ Convert a `Nat` into a `Char`. If the `Nat` does not encode a valid unicode scal
 def Char.ofNat (n : Nat) : Char :=
   dite (n.isValidChar)
     (fun h => Char.ofNatAux n h)
-    (fun _ => { val := ⟨BitVec.ofNatLt 0 (by decide)⟩, valid := Or.inl (by decide) })
+    (fun _ => { val := ⟨{ val := 0, isLt := by decide }⟩, valid := Or.inl (by decide) })
 
 theorem Char.eq_of_val_eq : ∀ {c d : Char}, Eq c.val d.val → Eq c d
   | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
@@ -3476,13 +3448,15 @@ This function is overridden with a native implementation.
 -/
 @[extern "lean_usize_to_uint64"]
 def USize.toUInt64 (u : USize) : UInt64 where
-  toBitVec := BitVec.ofNatLt u.toBitVec.toNat (
-        let ⟨⟨n, h⟩⟩ := u
-        show LT.lt n _ from
-        match System.Platform.numBits, System.Platform.numBits_eq, h with
-        | _, Or.inl rfl, h => Nat.lt_trans h (by decide)
-        | _, Or.inr rfl, h => h
-      )
+  val := {
+    val  := u.val.val
+    isLt :=
+      let ⟨n, h⟩ := u
+      show LT.lt n _ from
+      match USize.size, usize_size_eq, h with
+      | _, Or.inl rfl, h => Nat.lt_trans h (by decide)
+      | _, Or.inr rfl, h => h
+  }
 
 /-- An opaque hash mixing operation, used to implement hashing for tuples. -/
 @[extern "lean_uint64_mix_hash"]

src/Init/PropLemmas.lean

@@ -135,10 +135,6 @@ Both reduce to `b = false ∧ c = false` via `not_or`.
 
 theorem not_and_of_not_or_not (h : ¬a ∨ ¬b) : ¬(a ∧ b) := h.elim (mt (·.1)) (mt (·.2))
 
-/-! ## not equal -/
-
-theorem ne_of_apply_ne {α β : Sort _} (f : α → β) {x y : α} : f x ≠ f y → x ≠ y :=
-  mt <| congrArg _
 
 /-! ## Ite -/
 
@@ -388,17 +384,6 @@ theorem forall_prop_of_false {p : Prop} {q : p → Prop} (hn : ¬p) : (∀ h' :
 
 end quantifiers
 
-/-! ## membership -/
-
-section Mem
-variable [Membership α β] {s t : β} {a b : α}
-
-theorem ne_of_mem_of_not_mem (h : a ∈ s) : b ∉ s → a ≠ b := mt fun e => e ▸ h
-
-theorem ne_of_mem_of_not_mem' (h : a ∈ s) : a ∉ t → s ≠ t := mt fun e => e ▸ h
-
-end Mem
-
 /-! ## Nonempty -/
 
 @[simp] theorem nonempty_prop {p : Prop} : Nonempty p ↔ p :=
@@ -643,11 +628,11 @@ theorem decide_ite (u : Prop) [du : Decidable u] (p q : Prop)
     (@ite _ p h q (decide p)) = (decide p && q) := by
   split <;> simp_all
 
-@[deprecated ite_then_decide_self (since := "2024-08-29")]
+@[deprecated ite_then_decide_self]
 theorem ite_true_decide_same (p : Prop) [Decidable p] (b : Bool) :
   (if p then decide p else b) = (decide p || b) := ite_then_decide_self p b
 
-@[deprecated ite_false_decide_same (since := "2024-08-29")]
+@[deprecated ite_false_decide_same]
 theorem ite_false_decide_same (p : Prop) [Decidable p] (b : Bool) :
   (if p then b else decide p) = (decide p && b) := ite_else_decide_self p b
 

src/Init/SimpLemmas.lean

@@ -54,13 +54,6 @@ theorem forall_prop_domain_congr {p₁ p₂ : Prop} {q₁ : p₁ → Prop} {q₂
     : (∀ a : p₁, q₁ a) = (∀ a : p₂, q₂ a) := by
   subst h₁; simp [← h₂]
 
-theorem forall_prop_congr_dom {p₁ p₂ : Prop} (h : p₁ = p₂) (q : p₁ → Prop) :
-    (∀ a : p₁, q a) = (∀ a : p₂, q (h.substr a)) :=
-  h ▸ rfl
-
-theorem pi_congr {α : Sort u} {β β' : α → Sort v} (h : ∀ a, β a = β' a) : (∀ a, β a) = ∀ a, β' a :=
-  (funext h : β = β') ▸ rfl
-
 theorem let_congr {α : Sort u} {β : Sort v} {a a' : α} {b b' : α → β}
     (h₁ : a = a') (h₂ : ∀ x, b x = b' x) : (let x := a; b x) = (let x := a'; b' x) :=
   h₁ ▸ (funext h₂ : b = b') ▸ rfl

src/Init/SizeOf.lean

@@ -67,7 +67,6 @@ deriving instance SizeOf for PLift
 deriving instance SizeOf for ULift
 deriving instance SizeOf for Decidable
 deriving instance SizeOf for Fin
-deriving instance SizeOf for BitVec
 deriving instance SizeOf for UInt8
 deriving instance SizeOf for UInt16
 deriving instance SizeOf for UInt32

src/Init/SizeOfLemmas.lean

@@ -11,25 +11,22 @@ import Init.Data.Nat.Linear
 @[simp] protected theorem Fin.sizeOf (a : Fin n) : sizeOf a = a.val + 1 := by
   cases a; simp_arith
 
-@[simp] protected theorem BitVec.sizeOf (a : BitVec w) : sizeOf a = sizeOf a.toFin + 1 := by
-  cases a; simp_arith
+@[simp] protected theorem UInt8.sizeOf (a : UInt8) : sizeOf a = a.toNat + 2 := by
+  cases a; simp_arith [UInt8.toNat]
 
-@[simp] protected theorem UInt8.sizeOf (a : UInt8) : sizeOf a = a.toNat + 3 := by
-  cases a; simp_arith [UInt8.toNat, BitVec.toNat]
+@[simp] protected theorem UInt16.sizeOf (a : UInt16) : sizeOf a = a.toNat + 2 := by
+  cases a; simp_arith [UInt16.toNat]
 
-@[simp] protected theorem UInt16.sizeOf (a : UInt16) : sizeOf a = a.toNat + 3 := by
-  cases a; simp_arith [UInt16.toNat, BitVec.toNat]
+@[simp] protected theorem UInt32.sizeOf (a : UInt32) : sizeOf a = a.toNat + 2 := by
+  cases a; simp_arith [UInt32.toNat]
 
-@[simp] protected theorem UInt32.sizeOf (a : UInt32) : sizeOf a = a.toNat + 3 := by
-  cases a; simp_arith [UInt32.toNat, BitVec.toNat]
+@[simp] protected theorem UInt64.sizeOf (a : UInt64) : sizeOf a = a.toNat + 2 := by
+  cases a; simp_arith [UInt64.toNat]
 
-@[simp] protected theorem UInt64.sizeOf (a : UInt64) : sizeOf a = a.toNat + 3 := by
-  cases a; simp_arith [UInt64.toNat, BitVec.toNat]
+@[simp] protected theorem USize.sizeOf (a : USize) : sizeOf a = a.toNat + 2 := by
+  cases a; simp_arith [USize.toNat]
 
-@[simp] protected theorem USize.sizeOf (a : USize) : sizeOf a = a.toNat + 3 := by
-  cases a; simp_arith [USize.toNat, BitVec.toNat]
-
-@[simp] protected theorem Char.sizeOf (a : Char) : sizeOf a = a.toNat + 4 := by
+@[simp] protected theorem Char.sizeOf (a : Char) : sizeOf a = a.toNat + 3 := by
   cases a; simp_arith [Char.toNat]
 
 @[simp] protected theorem Subtype.sizeOf {α : Sort u_1} {p : α → Prop} (s : Subtype p) : sizeOf s = sizeOf s.val + 1 := by

src/Init/System/FilePath.lean

@@ -5,6 +5,8 @@ Authors: Leonardo de Moura, Sebastian Ullrich
 -/
 prelude
 import Init.System.Platform
+import Init.Data.String.Basic
+import Init.Data.Repr
 import Init.Data.ToString.Basic
 
 namespace System

src/Init/System/IO.lean

@@ -4,9 +4,13 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Luke Nelson, Jared Roesch, Leonardo de Moura, Sebastian Ullrich, Mac Malone
 -/
 prelude
+import Init.Control.Reader
+import Init.Data.String
+import Init.Data.ByteArray
 import Init.System.IOError
 import Init.System.FilePath
 import Init.System.ST
+import Init.Data.ToString.Macro
 import Init.Data.Ord
 
 open System

src/Init/System/IOError.lean

@@ -5,7 +5,10 @@ Authors: Simon Hudon
 -/
 
 prelude
+import Init.Core
+import Init.Data.UInt.Basic
 import Init.Data.ToString.Basic
+import Init.Data.String.Basic
 
 /--
 Imitate the structure of IOErrorType in Haskell: