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27 Commits

Author SHA1 Message Date
Leonardo de Moura
34fe8d3805 perf: precise cache for expr_eq_fn 2024-07-31 18:12:56 -07:00
Leonardo de Moura
ea84c036a7 perf: hashcons theorem value and type before type checking 2024-07-31 18:12:56 -07:00
Leonardo de Moura
6b57dceb04 feat: add sharecommon_persistent_fn
We also add `m_check_set` flag for controlling whether `check_cache`
should also inspect set of hashconsed objects or not.
2024-07-31 18:12:56 -07:00
Siddharth
c517688f1d feat: ushiftRight bitblasting (#4872)
This adds theorems `ushiftRight_rec_zero`, `ushiftRight_rec_succ`,
`ushiftRight_rec_eq`, and `shiftRight_eq_shiftRight_rec`.

---------

Co-authored-by: Tobias Grosser <github@grosser.es>
2024-07-31 21:44:06 +00:00
Leonardo de Moura
db594425bf refactor: sharecommon (#4887)
This PR also fixes a missing borrow annotation.
2024-07-31 19:13:12 +00:00
Kim Morrison
dcea47db02 chore: shorten suggestion about diagnostics (#4882)
This message is often incorporated into source files via `#guard_msgs`.
This change ensures it won't go over the 100 character ruler, and I
think is equally grammatical. :-)
2024-07-31 17:56:43 +00:00
Siddharth
f869902a4b feat: Nat simprocs for simplifying bit expressions (#4874)
This came up in the context of simplifying proof states for
https://github.com/leanprover/LNSym.
2024-07-31 17:26:05 +00:00
Sebastian Ullrich
d5a8c9647f fix: make import resolution case-sensitive on all platforms (#4538)
Co-authored-by: Mac Malone <tydeu@hatpress.net>
2024-07-31 16:48:14 +00:00
Sebastian Ullrich
d19bab0c27 feat: include command (#4883)
To be implemented in #4814
2024-07-31 13:25:54 +00:00
Sebastian Ullrich
6a4159c4a7 refactor: split out Lean.Language.Lean.Types (#4881) 2024-07-31 09:50:12 +00:00
Kim Morrison
8acdafd5b3 chore: correct doc-string for Array.swap! (#4869) 2024-07-31 04:02:30 +00:00
Kim Morrison
688da9d8a7 chore: updates to release_checklist.md (#4876)
Co-authored-by: Kyle Miller <kmill31415@gmail.com>
2024-07-31 04:02:19 +00:00
Kyle Miller
d5e7dbad80 fix: make "use `set_option diagnostics true" message conditional on current setting (#4781)
It is confusing that the message suggesting to use the `diagnostics`
option is given even when the option is already set. This PR makes use
of lazy message data to make the message contingent on the option being
false.

It also tones down the promise that there is any diagonostic information
available, since sometimes there is nothing to report.

Suggested by Johan Commelin.
2024-07-31 03:53:09 +00:00
Kyle Miller
82f48740dc chore: copy release notes from releases/v4.10.0 (#4864)
This also updates the 4.9.0 release notes with backported changes.
2024-07-31 03:30:13 +00:00
Kyle Miller
a827759f1d fix: mistake in statement of List.take_takeWhile (#4875)
This theorem is meant to say that `List.take` and `List.takeWhile`
commute.
2024-07-31 03:29:34 +00:00
Kim Morrison
a4015ca36c chore: rename PSigma.exists (#4878) 2024-07-31 03:26:17 +00:00
Kim Morrison
81719f94c9 chore: fix binder explicitness in List.map_subset (#4877) 2024-07-31 03:03:52 +00:00
Leonardo de Moura
afe0b5a013 perf: precise cache for foldConsts (#4871)
It addresses a performance issue at
https://github.com/leanprover/LNSym/blob/proof_size_expt/Proofs/SHA512/Experiments/Sym20.lean
2024-07-30 18:35:45 +00:00
Kim Morrison
90dab5e267 chore: fix naming of List.Subset lemmas (#4868) 2024-07-30 09:21:23 +00:00
Kim Morrison
6a904f2c85 chore: upstream List.eraseIdx lemmas (#4865) 2024-07-30 06:59:45 +00:00
Kim Morrison
2c396d6424 chore: upstream List.pairwise_iff_getElem (#4866) 2024-07-30 06:55:29 +00:00
Kim Morrison
69f86d6478 chore: split Init.Data.List.Lemmas (#4863)
Init.Data.List.Lemmas had reached 5000 lines: splitting into
function-specific files.
2024-07-30 03:17:34 +00:00
Joachim Breitner
4ea55687a5 refactor: deriving DecidableEq to use termination_by structural (#4826)
now that we support structural mutual recursion, I expect that every
`DecidableEq` instance be implemented using structural recursion, so
let's be explicit about it.
2024-07-29 21:24:05 +00:00
Kyle Miller
69c71f6476 fix: make elabAsElim aware of explicit motive arguments (#4817)
Some eliminators (such as `False.rec`) have an explicit motive argument.
The `elabAsElim` elaborator assumed that all motives are implicit.

If the explicit motive argument is `_`, then it uses the elab-as-elim
procedure, and otherwise it falls back to the standard app elaborator.

Furthermore, if an explicit elaborator is not provided, it falls back to
treating the elaborator as being implicit, which is convenient for
writing `h.rec` rather than `h.rec _`. Rationale: for `False.rec`, this
simulates it having an implicit motive, and also motives are generally
not going to be available in the expected type.

Closes #4347
2024-07-29 19:18:47 +00:00
Kyle Miller
7f128b39e7 feat: more than one optional argument can be omitted while pretty printing (#4854)
Before, the delaborator was conservative about omitting optional
arguments, only omitting the very last one. Now it can omit arbitrarily
long sequences of optional arguments from the end.

For simplicity of implementation, every optional argument is delaborated
and then potentially discarded. It could save state and lazily
delaborate, but we're running under the hypothesis that most optional
arguments are for very simple values (like `true`, `false`, or a numeric
literal), so it is unlikely that efficiency gains, if any, are worth it.
In particular, in the future structure constructors will have optional
arguments, but `unexpandStructureInstance` assumes none of the optional
fields are omitted.

Closes #4812
2024-07-29 19:02:39 +00:00
Kim Morrison
a845a007ac chore: fix universe in PSigma.exists (#4862) 2024-07-29 12:30:31 +00:00
Sebastian Ullrich
abf4206e9c chore: CI: fix msys2 2024-07-29 10:25:59 +02:00
111 changed files with 4867 additions and 3943 deletions

View File

@@ -14,10 +14,289 @@ Development in progress.
v4.10.0
----------
Release candidate, release notes will be copied from branch `releases/v4.10.0` once completed.
### Language features, tactics, and metaprograms
* `split` tactic:
* [#4401](https://github.com/leanprover/lean4/pull/4401) improves the strategy `split` uses to generalize discriminants of matches and adds `trace.split.failure` trace class for diagnosing issues.
* `rw` tactic:
* [#4385](https://github.com/leanprover/lean4/pull/4385) prevents the tactic from claiming pre-existing goals are new subgoals.
* [dac1da](https://github.com/leanprover/lean4/commit/dac1dacc5b39911827af68247d575569d9c399b5) adds configuration for ordering new goals, like for `apply`.
* `simp` tactic:
* [#4430](https://github.com/leanprover/lean4/pull/4430) adds `dsimproc`s for `if` expressions (`ite` and `dite`).
* [#4434](https://github.com/leanprover/lean4/pull/4434) improves heuristics for unfolding. Equational lemmas now have priorities where more-specific equationals lemmas are tried first before a possible catch-all.
* [#4481](https://github.com/leanprover/lean4/pull/4481) fixes an issue where function-valued `OfNat` numeric literals would become denormalized.
* [#4467](https://github.com/leanprover/lean4/pull/4467) fixes an issue where dsimp theorems might not apply to literals.
* [#4484](https://github.com/leanprover/lean4/pull/4484) fixes the source position for the warning for deprecated simp arguments.
* [#4258](https://github.com/leanprover/lean4/pull/4258) adds docstrings for `dsimp` configuration.
* [#4567](https://github.com/leanprover/lean4/pull/4567) improves the accuracy of used simp lemmas reported by `simp?`.
* [fb9727](https://github.com/leanprover/lean4/commit/fb97275dcbb683efe6da87ed10a3f0cd064b88fd) adds (but does not implement) the simp configuration option `implicitDefEqProofs`, which will enable including `rfl`-theorems in proof terms.
* `omega` tactic:
* [#4360](https://github.com/leanprover/lean4/pull/4360) makes the tactic generate error messages lazily, improving its performance when used in tactic combinators.
* `bv_omega` tactic:
* [#4579](https://github.com/leanprover/lean4/pull/4579) works around changes to the definition of `Fin.sub` in this release.
* [#4490](https://github.com/leanprover/lean4/pull/4490) sets up groundwork for a tactic index in generated documentation, as there was in Lean 3. See PR description for details.
* **Commands**
* [#4370](https://github.com/leanprover/lean4/pull/4370) makes the `variable` command fully elaborate binders during validation, fixing an issue where some errors would be reported only at the next declaration.
* [#4408](https://github.com/leanprover/lean4/pull/4408) fixes a discrepency in universe parameter order between `theorem` and `def` declarations.
* [#4493](https://github.com/leanprover/lean4/pull/4493) and
[#4482](https://github.com/leanprover/lean4/pull/4482) fix a discrepancy in the elaborators for `theorem`, `def`, and `example`,
making `Prop`-valued `example`s and other definition commands elaborate like `theorem`s.
* [8f023b](https://github.com/leanprover/lean4/commit/8f023b85c554186ae562774b8122322d856c674e), [3c4d6b](https://github.com/leanprover/lean4/commit/3c4d6ba8648eb04d90371eb3fdbd114d16949501) and [0783d0](https://github.com/leanprover/lean4/commit/0783d0fcbe31b626fbd3ed2f29d838e717f09101) change the `#reduce` command to be able to control what gets reduced.
For example, `#reduce (proofs := true) (types := false) e` reduces both proofs and types in the expression `e`.
By default, neither proofs or types are reduced.
* [#4489](https://github.com/leanprover/lean4/pull/4489) fixes an elaboration bug in `#check_tactic`.
* [#4505](https://github.com/leanprover/lean4/pull/4505) adds support for `open _root_.<namespace>`.
* **Options**
* [#4576](https://github.com/leanprover/lean4/pull/4576) adds the `debug.byAsSorry` option. Setting `set_option debug.byAsSorry true` causes all `by ...` terms to elaborate as `sorry`.
* [7b56eb](https://github.com/leanprover/lean4/commit/7b56eb20a03250472f4b145118ae885274d1f8f7) and [d8e719](https://github.com/leanprover/lean4/commit/d8e719f9ab7d049e423473dfc7a32867d32c856f) add the `debug.skipKernelTC` option. Setting `set_option debug.skipKernelTC true` turns off kernel typechecking. This is meant for temporarily working around kernel performance issues, and it compromises soundness since buggy tactics may produce invalid proofs, which will not be caught if this option is set to true.
* [#4301](https://github.com/leanprover/lean4/pull/4301)
adds a linter to flag situations where a local variable's name is one of
the argumentless constructors of its type. This can arise when a user either
doesn't open a namespace or doesn't add a dot or leading qualifier, as
in the following:
```lean
inductive Tree (α : Type) where
| leaf
| branch (left : Tree α) (val : α) (right : Tree α)
def depth : Tree α → Nat
| leaf => 0
```
With this linter, the `leaf` pattern is highlighted as a local
variable whose name overlaps with the constructor `Tree.leaf`.
The linter can be disabled with `set_option linter.constructorNameAsVariable false`.
Additionally, the error message that occurs when a name in a pattern that takes arguments isn't valid now suggests similar names that would be valid. This means that the following definition:
```lean
def length (list : List α) : Nat :=
match list with
| nil => 0
| cons x xs => length xs + 1
```
now results in the following warning:
```
warning: Local variable 'nil' resembles constructor 'List.nil' - write '.nil' (with a dot) or 'List.nil' to use the constructor.
note: this linter can be disabled with `set_option linter.constructorNameAsVariable false`
```
and error:
```
invalid pattern, constructor or constant marked with '[match_pattern]' expected
Suggestion: 'List.cons' is similar
```
* **Metaprogramming**
* [#4454](https://github.com/leanprover/lean4/pull/4454) adds public `Name.isInternalDetail` function for filtering declarations using naming conventions for internal names.
* **Other fixes or improvements**
* [#4416](https://github.com/leanprover/lean4/pull/4416) sorts the ouput of `#print axioms` for determinism.
* [#4528](https://github.com/leanprover/lean4/pull/4528) fixes error message range for the cdot focusing tactic.
### Language server, widgets, and IDE extensions
* [#4443](https://github.com/leanprover/lean4/pull/4443) makes the watchdog be more resilient against badly behaving clients.
### Pretty printing
* [#4433](https://github.com/leanprover/lean4/pull/4433) restores fallback pretty printers when context is not available, and documents `addMessageContext`.
* [#4556](https://github.com/leanprover/lean4/pull/4556) introduces `pp.maxSteps` option and sets the default value of `pp.deepTerms` to `false`. Together, these keep excessively large or deep terms from overwhelming the Infoview.
### Library
* [#4560](https://github.com/leanprover/lean4/pull/4560) splits `GetElem` class into `GetElem` and `GetElem?`.
This enables removing `Decidable` instance arguments from `GetElem.getElem?` and `GetElem.getElem!`, improving their rewritability.
See the docstrings for these classes for more information.
* `Array`
* [#4389](https://github.com/leanprover/lean4/pull/4389) makes `Array.toArrayAux_eq` be a `simp` lemma.
* [#4399](https://github.com/leanprover/lean4/pull/4399) improves robustness of the proof for `Array.reverse_data`.
* `List`
* [#4469](https://github.com/leanprover/lean4/pull/4469) and [#4475](https://github.com/leanprover/lean4/pull/4475) improve the organization of the `List` API.
* [#4470](https://github.com/leanprover/lean4/pull/4470) improves the `List.set` and `List.concat` API.
* [#4472](https://github.com/leanprover/lean4/pull/4472) upstreams lemmas about `List.filter` from Batteries.
* [#4473](https://github.com/leanprover/lean4/pull/4473) adjusts `@[simp]` attributes.
* [#4488](https://github.com/leanprover/lean4/pull/4488) makes `List.getElem?_eq_getElem` be a simp lemma.
* [#4487](https://github.com/leanprover/lean4/pull/4487) adds missing `List.replicate` API.
* [#4521](https://github.com/leanprover/lean4/pull/4521) adds lemmas about `List.map`.
* [#4500](https://github.com/leanprover/lean4/pull/4500) changes `List.length_cons` to use `as.length + 1` instead of `as.length.succ`.
* [#4524](https://github.com/leanprover/lean4/pull/4524) fixes the statement of `List.filter_congr`.
* [#4525](https://github.com/leanprover/lean4/pull/4525) changes binder explicitness in `List.bind_map`.
* [#4550](https://github.com/leanprover/lean4/pull/4550) adds `maximum?_eq_some_iff'` and `minimum?_eq_some_iff?`.
* [#4400](https://github.com/leanprover/lean4/pull/4400) switches the normal forms for indexing `List` and `Array` to `xs[n]` and `xs[n]?`.
* `HashMap`
* [#4372](https://github.com/leanprover/lean4/pull/4372) fixes linearity in `HashMap.insert` and `HashMap.erase`, leading to a 40% speedup in a replace-heavy workload.
* `Option`
* [#4403](https://github.com/leanprover/lean4/pull/4403) generalizes type of `Option.forM` from `Unit` to `PUnit`.
* [#4504](https://github.com/leanprover/lean4/pull/4504) remove simp attribute from `Option.elim` and instead adds it to individal reduction lemmas, making unfolding less aggressive.
* `Nat`
* [#4242](https://github.com/leanprover/lean4/pull/4242) adds missing theorems for `n + 1` and `n - 1` normal forms.
* [#4486](https://github.com/leanprover/lean4/pull/4486) makes `Nat.min_assoc` be a simp lemma.
* [#4522](https://github.com/leanprover/lean4/pull/4522) moves `@[simp]` from `Nat.pred_le` to `Nat.sub_one_le`.
* [#4532](https://github.com/leanprover/lean4/pull/4532) changes various `Nat.succ n` to `n + 1`.
* `Int`
* [#3850](https://github.com/leanprover/lean4/pull/3850) adds complete div/mod simprocs for `Int`.
* `String`/`Char`
* [#4357](https://github.com/leanprover/lean4/pull/4357) make the byte size interface be `Nat`-valued with functions `Char.utf8Size` and `String.utf8ByteSize`.
* [#4438](https://github.com/leanprover/lean4/pull/4438) upstreams `Char.ext` from Batteries and adds some `Char` documentation to the manual.
* `Fin`
* [#4421](https://github.com/leanprover/lean4/pull/4421) adjusts `Fin.sub` to be more performant in definitional equality checks.
* `Prod`
* [#4526](https://github.com/leanprover/lean4/pull/4526) adds missing `Prod.map` lemmas.
* [#4533](https://github.com/leanprover/lean4/pull/4533) fixes binder explicitness in lemmas.
* `BitVec`
* [#4428](https://github.com/leanprover/lean4/pull/4428) adds missing `simproc` for `BitVec` equality.
* [#4417](https://github.com/leanprover/lean4/pull/4417) adds `BitVec.twoPow` and lemmas, toward bitblasting multiplication for LeanSAT.
* `Std` library
* [#4499](https://github.com/leanprover/lean4/pull/4499) introduces `Std`, a library situated between `Init` and `Lean`, providing functionality not in the prelude both to Lean's implementation and to external users.
* **Other fixes or improvements**
* [#3056](https://github.com/leanprover/lean4/pull/3056) standardizes on using `(· == a)` over `(a == ·)`.
* [#4502](https://github.com/leanprover/lean4/pull/4502) fixes errors reported by running the library through the the Batteries linters.
### Lean internals
* [#4391](https://github.com/leanprover/lean4/pull/4391) makes `getBitVecValue?` recognize `BitVec.ofNatLt`.
* [#4410](https://github.com/leanprover/lean4/pull/4410) adjusts `instantiateMVars` algorithm to zeta reduce `let` expressions while beta reducing instantiated metavariables.
* [#4420](https://github.com/leanprover/lean4/pull/4420) fixes occurs check for metavariable assignments to also take metavariable types into account.
* [#4425](https://github.com/leanprover/lean4/pull/4425) fixes `forEachModuleInDir` to iterate over each Lean file exactly once.
* [#3886](https://github.com/leanprover/lean4/pull/3886) adds support to build Lean core oleans using Lake.
* **Defeq and WHNF algorithms**
* [#4387](https://github.com/leanprover/lean4/pull/4387) improves performance of `isDefEq` by eta reducing lambda-abstracted terms during metavariable assignments, since these are beta reduced during metavariable instantiation anyway.
* [#4388](https://github.com/leanprover/lean4/pull/4388) removes redundant code in `isDefEqQuickOther`.
* **Typeclass inference**
* [#4530](https://github.com/leanprover/lean4/pull/4530) fixes handling of metavariables when caching results at `synthInstance?`.
* **Elaboration**
* [#4426](https://github.com/leanprover/lean4/pull/4426) makes feature where the "don't know how to synthesize implicit argument" error reports the name of the argument more reliable.
* [#4497](https://github.com/leanprover/lean4/pull/4497) fixes a name resolution bug for generalized field notation (dot notation).
* [#4536](https://github.com/leanprover/lean4/pull/4536) blocks the implicit lambda feature for `(e :)` notation.
* [#4562](https://github.com/leanprover/lean4/pull/4562) makes it be an error for there to be two functions with the same name in a `where`/`let rec` block.
* Recursion principles
* [#4549](https://github.com/leanprover/lean4/pull/4549) refactors `findRecArg`, extracting `withRecArgInfo`.
Errors are now reported in parameter order rather than the order they are tried (non-indices are tried first).
For every argument, it will say why it wasn't tried, even if the reason is obvious (e.g. a fixed prefix or is `Prop`-typed, etc.).
* Porting core C++ to Lean
* [#4474](https://github.com/leanprover/lean4/pull/4474) takes a step to refactor `constructions` toward a future port to Lean.
* [#4498](https://github.com/leanprover/lean4/pull/4498) ports `mk_definition_inferring_unsafe` to Lean.
* [#4516](https://github.com/leanprover/lean4/pull/4516) ports `recOn` construction to Lean.
* [#4517](https://github.com/leanprover/lean4/pull/4517), [#4653](https://github.com/leanprover/lean4/pull/4653), and [#4651](https://github.com/leanprover/lean4/pull/4651) port `below` and `brecOn` construction to Lean.
* Documentation
* [#4501](https://github.com/leanprover/lean4/pull/4501) adds a more-detailed docstring for `PersistentEnvExtension`.
* **Other fixes or improvements**
* [#4382](https://github.com/leanprover/lean4/pull/4382) removes `@[inline]` attribute from `NameMap.find?`, which caused respecialization at each call site.
* [5f9ded](https://github.com/leanprover/lean4/commit/5f9dedfe5ee9972acdebd669f228f487844a6156) improves output of `trace.Elab.snapshotTree`.
* [#4424](https://github.com/leanprover/lean4/pull/4424) removes "you might need to open '{dir}' in your editor" message that is now handled by Lake and the VS Code extension.
* [#4451](https://github.com/leanprover/lean4/pull/4451) improves the performance of `CollectMVars` and `FindMVar`.
* [#4479](https://github.com/leanprover/lean4/pull/4479) adds missing `DecidableEq` and `Repr` instances for intermediate structures used by the `BitVec` and `Fin` simprocs.
* [#4492](https://github.com/leanprover/lean4/pull/4492) adds tests for a previous `isDefEq` issue.
* [9096d6](https://github.com/leanprover/lean4/commit/9096d6fc7180fe533c504f662bcb61550e4a2492) removes `PersistentHashMap.size`.
* [#4508](https://github.com/leanprover/lean4/pull/4508) fixes `@[implemented_by]` for functions defined by well-founded recursion.
* [#4509](https://github.com/leanprover/lean4/pull/4509) adds additional tests for `apply?` tactic.
* [d6eab3](https://github.com/leanprover/lean4/commit/d6eab393f4df9d473b5736d636b178eb26d197e6) fixes a benchmark.
* [#4563](https://github.com/leanprover/lean4/pull/4563) adds a workaround for a bug in `IndPredBelow.mkBelowMatcher`.
* **Cleanup:** [#4380](https://github.com/leanprover/lean4/pull/4380), [#4431](https://github.com/leanprover/lean4/pull/4431), [#4494](https://github.com/leanprover/lean4/pull/4494), [e8f768](https://github.com/leanprover/lean4/commit/e8f768f9fd8cefc758533bc76e3a12b398ed4a39), [de2690](https://github.com/leanprover/lean4/commit/de269060d17a581ed87f40378dbec74032633b27), [d3a756](https://github.com/leanprover/lean4/commit/d3a7569c97123d022828106468d54e9224ed8207), [#4404](https://github.com/leanprover/lean4/pull/4404), [#4537](https://github.com/leanprover/lean4/pull/4537).
### Compiler, runtime, and FFI
* [d85d3d](https://github.com/leanprover/lean4/commit/d85d3d5f3a09ff95b2ee47c6f89ef50b7e339126) fixes criterion for tail-calls in ownership calculation.
* [#3963](https://github.com/leanprover/lean4/pull/3963) adds validation of UTF-8 at the C++-to-Lean boundary in the runtime.
* [#4512](https://github.com/leanprover/lean4/pull/4512) fixes missing unboxing in interpreter when loading initialized value.
* [#4477](https://github.com/leanprover/lean4/pull/4477) exposes the compiler flags for the bundled C compiler (clang).
### Lake
* [#4384](https://github.com/leanprover/lean4/pull/4384) deprecates `inputFile` and replaces it with `inputBinFile` and `inputTextFile`. Unlike `inputBinFile` (and `inputFile`), `inputTextFile` normalizes line endings, which helps ensure text file traces are platform-independent.
* [#4371](https://github.com/leanprover/lean4/pull/4371) simplifies dependency resolution code.
* [#4439](https://github.com/leanprover/lean4/pull/4439) touches up the Lake configuration DSL and makes other improvements:
string literals can now be used instead of identifiers for names,
avoids using French quotes in `lake new` and `lake init` templates,
changes the `exe` template to use `Main` for the main module,
improves the `math` template error if `lean-toolchain` fails to download,
and downgrades unknown configuration fields from an error to a warning to improve cross-version compatibility.
* [#4496](https://github.com/leanprover/lean4/pull/4496) tweaks `require` syntax and updates docs. Now `require` in TOML for a package name such as `doc-gen4` does not need French quotes.
* [#4485](https://github.com/leanprover/lean4/pull/4485) fixes a bug where package versions in indirect dependencies would take precedence over direct dependencies.
* [#4478](https://github.com/leanprover/lean4/pull/4478) fixes a bug where Lake incorrectly included the module dynamic library in a platform-independent trace.
* [#4529](https://github.com/leanprover/lean4/pull/4529) fixes some issues with bad import errors.
A bad import in an executable no longer prevents the executable's root
module from being built. This also fixes a problem where the location
of a transitive bad import would not been shown.
The root module of the executable now respects `nativeFacets`.
* [#4564](https://github.com/leanprover/lean4/pull/4564) fixes a bug where non-identifier script names could not be entered on the CLI without French quotes.
* [#4566](https://github.com/leanprover/lean4/pull/4566) addresses a few issues with precompiled libraries.
* Fixes a bug where Lake would always precompile the package of a module.
* If a module is precompiled, it now precompiles its imports. Previously, it would only do this if imported.
* [#4495](https://github.com/leanprover/lean4/pull/4495), [#4692](https://github.com/leanprover/lean4/pull/4692), [#4849](https://github.com/leanprover/lean4/pull/4849)
add a new type of `require` that fetches package metadata from a
registry API endpoint (e.g. Reservoir) and then clones a Git package
using the information provided. To require such a dependency, the new
syntax is:
```lean
require <scope> / <pkg-name> [@ git <rev>]
-- Examples:
require "leanprover" / "doc-gen4"
require "leanprover-community" / "proofwidgets" @ git "v0.0.39"
```
Or in TOML:
```toml
[[require]]
name = "<pkg-name>"
scope = "<scope>"
rev = "<rev>"
```
Unlike with Git dependencies, Lake can make use of the richer
information provided by the registry to determine the default branch of
the package. This means for repositories of packages like `doc-gen4`
which have a default branch that is not `master`, Lake will now use said
default branch (e.g., in `doc-gen4`'s case, `main`).
Lake also supports configuring the registry endpoint via an environment
variable: `RESERVIOR_API_URL`. Thus, any server providing a similar
interface to Reservoir can be used as the registry. Further
configuration options paralleling those of Cargo's [Alternative Registries](https://doc.rust-lang.org/cargo/reference/registries.html)
and [Source Replacement](https://doc.rust-lang.org/cargo/reference/source-replacement.html)
will come in the future.
### DevOps/CI
* [#4427](https://github.com/leanprover/lean4/pull/4427) uses Namespace runners for CI for `leanprover/lean4`.
* [#4440](https://github.com/leanprover/lean4/pull/4440) fixes speedcenter tests in CI.
* [#4441](https://github.com/leanprover/lean4/pull/4441) fixes that workflow change would break CI for unrebased PRs.
* [#4442](https://github.com/leanprover/lean4/pull/4442) fixes Wasm release-ci.
* [6d265b](https://github.com/leanprover/lean4/commit/6d265b42b117eef78089f479790587a399da7690) fixes for `github.event.pull_request.merge_commit_sha` sometimes not being available.
* [16cad2](https://github.com/leanprover/lean4/commit/16cad2b45c6a77efe4dce850dcdbaafaa7c91fc3) adds optimization for CI to not fetch complete history.
* [#4544](https://github.com/leanprover/lean4/pull/4544) causes releases to be marked as prerelease on GitHub.
* [#4446](https://github.com/leanprover/lean4/pull/4446) switches Lake to using `src/lake/lakefile.toml` to avoid needing to load a version of Lake to build Lake.
* Nix
* [5eb5fa](https://github.com/leanprover/lean4/commit/5eb5fa49cf9862e99a5bccff8d4ca1a062f81900) fixes `update-stage0-commit` for Nix.
* [#4476](https://github.com/leanprover/lean4/pull/4476) adds gdb to Nix shell.
* [e665a0](https://github.com/leanprover/lean4/commit/e665a0d716dc42ba79b339b95e01eb99fe932cb3) fixes `update-stage0` for Nix.
* [4808eb](https://github.com/leanprover/lean4/commit/4808eb7c4bfb98f212b865f06a97d46c44978a61) fixes `cacheRoots` for Nix.
* [#3811](https://github.com/leanprover/lean4/pull/3811) adds platform-dependent flag to lib target.
* [#4587](https://github.com/leanprover/lean4/pull/4587) adds linking of `-lStd` back into nix build flags on darwin.
### Breaking changes
* `Char.csize` is replaced by `Char.utf8Size` ([#4357](https://github.com/leanprover/lean4/pull/4357)).
* Library lemmas now are in terms of `(· == a)` over `(a == ·)` ([#3056](https://github.com/leanprover/lean4/pull/3056)).
* Now the normal forms for indexing into `List` and `Array` is `xs[n]` and `xs[n]?` rather than using functions like `List.get` ([#4400](https://github.com/leanprover/lean4/pull/4400)).
* Sometimes terms created via a sequence of unifications will be more eta reduced than before and proofs will require adaptation ([#4387](https://github.com/leanprover/lean4/pull/4387)).
* The `GetElem` class has been split into two; see the docstrings for `GetElem` and `GetElem?` for more information ([#4560](https://github.com/leanprover/lean4/pull/4560)).
v4.9.0
----------
----------
### Language features, tactics, and metaprograms
@@ -40,6 +319,8 @@ v4.9.0
* [#4395](https://github.com/leanprover/lean4/pull/4395) adds conservative fix for whitespace handling to avoid incremental reuse leading to goals in front of the text cursor being shown.
* [#4407](https://github.com/leanprover/lean4/pull/4407) fixes non-incremental commands in macros blocking further incremental reporting.
* [#4436](https://github.com/leanprover/lean4/pull/4436) fixes incremental reporting when there are nested tactics in terms.
* [#4459](https://github.com/leanprover/lean4/pull/4459) adds incrementality support for `next` and `if` tactics.
* [#4554](https://github.com/leanprover/lean4/pull/4554) disables incrementality for tactics in terms in tactics.
* **Functional induction**
* [#4135](https://github.com/leanprover/lean4/pull/4135) ensures that the names used for functional induction are reserved.
* [#4327](https://github.com/leanprover/lean4/pull/4327) adds support for structural recursion on reflexive types.
@@ -85,7 +366,7 @@ v4.9.0
When `index := false`, only the head function is taken into account, like in Lean 3.
This feature can help users diagnose tricky simp failures or issues in code from libraries
developed using Lean 3 and then ported to Lean 4.
In the following example, it will report that `foo` is a problematic theorem.
```lean
opaque f : Nat → Nat → Nat
@@ -105,7 +386,7 @@ v4.9.0
opaque f : Nat → Nat → Nat
@[simp] theorem foo : f x (no_index (x, y).2) = y := by sorry
example : f a b ≤ b := by
simp -- `foo` is still applied with `index := true`
```
@@ -123,6 +404,8 @@ v4.9.0
* [#4267](https://github.com/leanprover/lean4/pull/4267) cases signature elaboration errors to show even if there are parse errors in the body.
* [#4368](https://github.com/leanprover/lean4/pull/4368) improves error messages when numeric literals fail to synthesize an `OfNat` instance,
including special messages warning when the expected type of the numeral can be a proposition.
* [#4643](https://github.com/leanprover/lean4/pull/4643) fixes issue leading to nested error messages and info trees vanishing, where snapshot subtrees were not restored on reuse.
* [#4657](https://github.com/leanprover/lean4/pull/4657) calculates error suppression per snapshot, letting elaboration errors appear even when there are later parse errors ([RFC #3556](https://github.com/leanprover/lean4/issues/3556)).
* **Metaprogramming**
* [#4167](https://github.com/leanprover/lean4/pull/4167) adds `Lean.MVarId.revertAll` to revert all free variables.
* [#4169](https://github.com/leanprover/lean4/pull/4169) adds `Lean.MVarId.ensureNoMVar` to ensure the goal's target contains no expression metavariables.
@@ -239,6 +522,8 @@ v4.9.0
* [#4192](https://github.com/leanprover/lean4/pull/4192) fixes restoration of infotrees when auto-bound implicit feature is activated,
fixing a pretty printing error in hovers and strengthening the unused variable linter.
* [dfb496](https://github.com/leanprover/lean4/commit/dfb496a27123c3864571aec72f6278e2dad1cecf) fixes `declareBuiltin` to allow it to be called multiple times per declaration.
* [#4569](https://github.com/leanprover/lean4/pull/4569) fixes an issue introduced in a merge conflict, where the interrupt exception was swallowed by some `tryCatchRuntimeEx` uses.
* [b056a0](https://github.com/leanprover/lean4/commit/b056a0b395bb728512a3f3e83bf9a093059d4301) adapts kernel interruption to the new cancellation system.
* Cleanup: [#4112](https://github.com/leanprover/lean4/pull/4112), [#4126](https://github.com/leanprover/lean4/pull/4126), [#4091](https://github.com/leanprover/lean4/pull/4091), [#4139](https://github.com/leanprover/lean4/pull/4139), [#4153](https://github.com/leanprover/lean4/pull/4153).
* Tests: [030406](https://github.com/leanprover/lean4/commit/03040618b8f9b35b7b757858483e57340900cdc4), [#4133](https://github.com/leanprover/lean4/pull/4133).
@@ -249,6 +534,7 @@ v4.9.0
* [#3915](https://github.com/leanprover/lean4/pull/3915) documents the runtime memory layout for inductive types.
### Lake
* [#4518](https://github.com/leanprover/lean4/pull/4518) makes trace reading more robust. Lake now rebuilds if trace files are invalid or unreadable and is backwards compatible with previous pure numeric traces.
* [#4057](https://github.com/leanprover/lean4/pull/4057) adds support for docstrings on `require` commands.
* [#4088](https://github.com/leanprover/lean4/pull/4088) improves hovers for `family_def` and `library_data` commands.
* [#4147](https://github.com/leanprover/lean4/pull/4147) adds default `README.md` to package templates
@@ -298,12 +584,14 @@ v4.9.0
* [#4333](https://github.com/leanprover/lean4/pull/4333) adjusts workflow to update Batteries in manifest when creating `lean-pr-testing-NNNN` Mathlib branches.
* [#4355](https://github.com/leanprover/lean4/pull/4355) simplifies `lean4checker` step of release checklist.
* [#4361](https://github.com/leanprover/lean4/pull/4361) adds installing elan to `pr-release` CI step.
* [#4628](https://github.com/leanprover/lean4/pull/4628) fixes the Windows build, which was missing an exported symbol.
### Breaking changes
While most changes could be considered to be a breaking change, this section makes special note of API changes.
* `Nat.zero_or` and `Nat.or_zero` have been swapped ([#4094](https://github.com/leanprover/lean4/pull/4094)).
* `IsLawfulSingleton` is now `LawfulSingleton` ([#4350](https://github.com/leanprover/lean4/pull/4350)).
* The `BitVec` literal notation is now `<num>#<term>` rather than `<term>#<term>`, and it is global rather than scoped. Use `BitVec.ofNat w x` rather than `x#w` when `x` is a not a numeric literal ([0d3051](https://github.com/leanprover/lean4/commit/0d30517dca094a07bcb462252f718e713b93ffba)).
* `BitVec.rotateLeft` and `BitVec.rotateRight` now take the shift modulo the bitwidth ([#4229](https://github.com/leanprover/lean4/pull/4229)).
* These are no longer simp lemmas:
`List.length_pos` ([#4172](https://github.com/leanprover/lean4/pull/4172)),

View File

@@ -5,8 +5,11 @@ See below for the checklist for release candidates.
We'll use `v4.6.0` as the intended release version as a running example.
- One week before the planned release, ensure that (1) someone has written the release notes and (2) someone has written the first draft of the release blog post.
If there is any material in `./releases_drafts/`, then the release notes are not done. (See the section "Writing the release notes".)
- One week before the planned release, ensure that
(1) someone has written the release notes and
(2) someone has written the first draft of the release blog post.
If there is any material in `./releases_drafts/` on the `releases/v4.6.0` branch, then the release notes are not done.
(See the section "Writing the release notes".)
- `git checkout releases/v4.6.0`
(This branch should already exist, from the release candidates.)
- `git pull`
@@ -187,6 +190,8 @@ We'll use `v4.7.0-rc1` as the intended release version in this example.
Please also make sure that whoever is handling social media knows the release is out.
- Begin the next development cycle (i.e. for `v4.8.0`) on the Lean repository, by making a PR that:
- Updates `src/CMakeLists.txt` to say `set(LEAN_VERSION_MINOR 8)`
- Replaces the "release notes will be copied" text in the `v4.6.0` section of `RELEASES.md` with the
finalized release notes from the `releases/v4.6.0` branch.
- Replaces the "development in progress" in the `v4.7.0` section of `RELEASES.md` with
```
Release candidate, release notes will be copied from `branch releases/v4.7.0` once completed.
@@ -222,12 +227,15 @@ Please read https://leanprover-community.github.io/contribute/tags_and_branches.
* This can either be done by the person managing this process directly,
or by soliciting assistance from authors of files, or generally helpful people on Zulip!
* Each repo has a `bump/v4.7.0` which accumulates reviewed changes adapting to new versions.
* Once `nightly-testing` is working on a given nightly, say `nightly-2024-02-15`, we:
* Once `nightly-testing` is working on a given nightly, say `nightly-2024-02-15`, we will create a PR to `bump/v4.7.0`.
* For Mathlib, there is a script in `scripts/create-adaptation-pr.sh` that automates this process.
* For Batteries and Aesop it is currently manual.
* For all of these repositories, the process is the same:
* Make sure `bump/v4.7.0` is up to date with `master` (by merging `master`, no PR necessary)
* Create from `bump/v4.7.0` a `bump/nightly-2024-02-15` branch.
* In that branch, `git merge --squash nightly-testing` to bring across changes from `nightly-testing`.
* In that branch, `git merge nightly-testing` to bring across changes from `nightly-testing`.
* Sanity check changes, commit, and make a PR to `bump/v4.7.0` from the `bump/nightly-2024-02-15` branch.
* Solicit review, merge the PR into `bump/v4,7,0`.
* Solicit review, merge the PR into `bump/v4.7.0`.
* It is always okay to merge in the following directions:
`master` -> `bump/v4.7.0` -> `bump/nightly-2024-02-15` -> `nightly-testing`.
Please remember to push any merges you make to intermediate steps!
@@ -239,7 +247,7 @@ The exact steps are a work in progress.
Here is the general idea:
* The work is done right on the `releases/v4.6.0` branch sometime after it is created but before the stable release is made.
The release notes for `v4.6.0` will be copied to `master`.
The release notes for `v4.6.0` will later be copied to `master` when we begin a new development cycle.
* There can be material for release notes entries in commit messages.
* There can also be pre-written entries in `./releases_drafts`, which should be all incorporated in the release notes and then deleted from the branch.
See `./releases_drafts/README.md` for more information.

View File

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

View File

@@ -67,12 +67,8 @@ theorem ite_some_none_eq_none [Decidable P] :
-- This is not marked as `simp` as it is already handled by `dite_eq_right_iff`.
theorem dite_some_none_eq_none [Decidable P] {x : P α} :
(if h : P then some (x h) else none) = none ¬P := by
simp only [dite_eq_right_iff]
rfl
simp
@[simp] theorem dite_some_none_eq_some [Decidable P] {x : P α} {y : α} :
(if h : P then some (x h) else none) = some y h : P, x h = y := by
by_cases h : P <;> simp only [h, dite_cond_eq_true, dite_cond_eq_false, Option.some.injEq,
false_iff, not_exists]
case pos => exact fun h_eq Exists.intro h h_eq, fun h_exists => h_exists.2
case neg => exact fun h_false _ h_false
by_cases h : P <;> simp [h]

View File

@@ -1204,12 +1204,12 @@ def Prod.map {α₁ : Type u₁} {α₂ : Type u₂} {β₁ : Type v₁} {β₂
/-! # Dependent products -/
theorem PSigma.exists {α : Type u} {p : α Prop} : (PSigma (fun x => p x)) Exists (fun x => p x)
theorem Exists.of_psigma_prop {α : Sort u} {p : α Prop} : (PSigma (fun x => p x)) Exists (fun x => p x)
| x, hx => x, hx
@[deprecated PSigma.exists (since := "2024-07-27")]
@[deprecated Exists.of_psigma_prop (since := "2024-07-27")]
theorem ex_of_PSigma {α : Type u} {p : α Prop} : (PSigma (fun x => p x)) Exists (fun x => p x) :=
PSigma.exists
Exists.of_psigma_prop
protected theorem PSigma.eta {α : Sort u} {β : α Sort v} {a₁ a₂ : α} {b₁ : β a₁} {b₂ : β a₂}
(h₁ : a₁ = a₂) (h₂ : Eq.ndrec b₁ h₁ = b₂) : PSigma.mk a₁ b₁ = PSigma.mk a₂ b₂ := by

View File

@@ -108,7 +108,7 @@ def swap (a : Array α) (i j : @& Fin a.size) : Array α :=
a'.set (size_set a i v₂ j) v₁
/--
Swaps two entries in an array, or panics if either index is out of bounds.
Swaps two entries in an array, or returns the array unchanged if either index is out of bounds.
This will perform the update destructively provided that `a` has a reference
count of 1 when called.

View File

@@ -6,7 +6,7 @@ Authors: Mario Carneiro
prelude
import Init.Data.Nat.MinMax
import Init.Data.Nat.Lemmas
import Init.Data.List.Lemmas
import Init.Data.List.Monadic
import Init.Data.Fin.Basic
import Init.Data.Array.Mem
import Init.TacticsExtra

View File

@@ -5,7 +5,7 @@ Authors: Markus Himmel
-/
prelude
import Init.Data.Array.Lemmas
import Init.Data.List.TakeDrop
import Init.Data.List.Nat.TakeDrop
namespace Array

View File

@@ -403,12 +403,8 @@ theorem shiftLeftRec_eq {x : BitVec w₁} {y : BitVec w₂} {n : Nat} :
induction n generalizing x y
case zero =>
ext i
simp only [shiftLeftRec_zero, twoPow_zero, Nat.reduceAdd, truncate_one]
suffices (y &&& 1#w₂) = zeroExtend w₂ (ofBool (y.getLsb 0)) by simp [this]
ext i
by_cases h : (i : Nat) = 0
· simp [h, Bool.and_comm]
· simp [h]; omega
simp only [shiftLeftRec_zero, twoPow_zero, Nat.reduceAdd, truncate_one,
and_one_eq_zeroExtend_ofBool_getLsb]
case succ n ih =>
simp only [shiftLeftRec_succ, and_twoPow]
rw [ih]
@@ -431,4 +427,67 @@ theorem shiftLeft_eq_shiftLeftRec (x : BitVec w₁) (y : BitVec w₂) :
· simp [of_length_zero]
· simp [shiftLeftRec_eq]
/- ### Logical shift right (ushiftRight) recurrence for bitblasting -/
/--
`ushiftRightRec x y n` shifts `x` logically to the right by the first `n` bits of `y`.
The theorem `shiftRight_eq_ushiftRightRec` proves the equivalence
of `(x >>> y)` and `ushiftRightRec`.
Together with equations `ushiftRightRec_zero`, `ushiftRightRec_succ`,
this allows us to unfold `ushiftRight` into a circuit for bitblasting.
-/
def ushiftRightRec (x : BitVec w₁) (y : BitVec w₂) (n : Nat) : BitVec w₁ :=
let shiftAmt := (y &&& (twoPow w₂ n))
match n with
| 0 => x >>> shiftAmt
| n + 1 => (ushiftRightRec x y n) >>> shiftAmt
@[simp]
theorem ushiftRightRec_zero (x : BitVec w₁) (y : BitVec w₂) :
ushiftRightRec x y 0 = x >>> (y &&& twoPow w₂ 0) := by
simp [ushiftRightRec]
@[simp]
theorem ushiftRightRec_succ (x : BitVec w₁) (y : BitVec w₂) :
ushiftRightRec x y (n + 1) = (ushiftRightRec x y n) >>> (y &&& twoPow w₂ (n + 1)) := by
simp [ushiftRightRec]
/--
If `y &&& z = 0`, `x >>> (y ||| z) = x >>> y >>> z`.
This follows as `y &&& z = 0` implies `y ||| z = y + z`,
and thus `x >>> (y ||| z) = x >>> (y + z) = x >>> y >>> z`.
-/
theorem ushiftRight'_or_of_and_eq_zero {x : BitVec w₁} {y z : BitVec w₂}
(h : y &&& z = 0#w₂) :
x >>> (y ||| z) = x >>> y >>> z := by
simp [ add_eq_or_of_and_eq_zero _ _ h, toNat_add_of_and_eq_zero h, shiftRight_add]
theorem ushiftRightRec_eq (x : BitVec w₁) (y : BitVec w₂) (n : Nat) :
ushiftRightRec x y n = x >>> (y.truncate (n + 1)).zeroExtend w₂ := by
induction n generalizing x y
case zero =>
ext i
simp only [ushiftRightRec_zero, twoPow_zero, Nat.reduceAdd,
and_one_eq_zeroExtend_ofBool_getLsb, truncate_one]
case succ n ih =>
simp only [ushiftRightRec_succ, and_twoPow]
rw [ih]
by_cases h : y.getLsb (n + 1) <;> simp only [h, reduceIte]
· rw [zeroExtend_truncate_succ_eq_zeroExtend_truncate_or_twoPow_of_getLsb_true h,
ushiftRight'_or_of_and_eq_zero]
simp
· simp [zeroExtend_truncate_succ_eq_zeroExtend_truncate_of_getLsb_false, h]
/--
Show that `x >>> y` can be written in terms of `ushiftRightRec`.
This can be unfolded in terms of `ushiftRightRec_zero`, `ushiftRightRec_succ` for bitblasting.
-/
theorem shiftRight_eq_ushiftRightRec (x : BitVec w₁) (y : BitVec w₂) :
x >>> y = ushiftRightRec x y (w₂ - 1) := by
rcases w₂ with rfl | w₂
· simp [of_length_zero]
· simp [ushiftRightRec_eq]
end BitVec

View File

@@ -731,6 +731,16 @@ theorem getLsb_shiftLeft' {x : BitVec w₁} {y : BitVec w₂} {i : Nat} :
getLsb (x >>> i) j = getLsb x (i+j) := by
unfold getLsb ; simp
@[simp]
theorem ushiftRight_zero_eq (x : BitVec w) : x >>> 0 = x := by
simp [bv_toNat]
/-! ### ushiftRight reductions from BitVec to Nat -/
@[simp]
theorem ushiftRight_eq' (x : BitVec w₁) (y : BitVec w₂) :
x >>> y = x >>> y.toNat := by rfl
/-! ### sshiftRight -/
theorem sshiftRight_eq {x : BitVec n} {i : Nat} :
@@ -1549,4 +1559,12 @@ theorem zeroExtend_truncate_succ_eq_zeroExtend_truncate_or_twoPow_of_getLsb_true
simp [hx]
· by_cases hik' : k < i + 1 <;> simp [hik, hik'] <;> omega
/-- Bitwise and of `(x : BitVec w)` with `1#w` equals zero extending `x.lsb` to `w`. -/
theorem and_one_eq_zeroExtend_ofBool_getLsb {x : BitVec w} :
(x &&& 1#w) = zeroExtend w (ofBool (x.getLsb 0)) := by
ext i
simp only [getLsb_and, getLsb_one, getLsb_zeroExtend, Fin.is_lt, decide_True, getLsb_ofBool,
Bool.true_and]
by_cases h : (0 = (i : Nat)) <;> simp [h] <;> omega
end BitVec

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@@ -4,13 +4,20 @@ Released under Apache 2.0 license as described in the file LICENSE.
Authors: Leonardo de Moura
-/
prelude
import Init.Data.List.Attach
import Init.Data.List.Basic
import Init.Data.List.BasicAux
import Init.Data.List.Control
import Init.Data.List.Lemmas
import Init.Data.List.Attach
import Init.Data.List.Count
import Init.Data.List.Erase
import Init.Data.List.Find
import Init.Data.List.Impl
import Init.Data.List.TakeDrop
import Init.Data.List.Notation
import Init.Data.List.Range
import Init.Data.List.Lemmas
import Init.Data.List.MinMax
import Init.Data.List.Monadic
import Init.Data.List.Nat
import Init.Data.List.Notation
import Init.Data.List.Pairwise
import Init.Data.List.Sublist
import Init.Data.List.TakeDrop
import Init.Data.List.Zip

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@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
Authors: Mario Carneiro
-/
prelude
import Init.Data.List.Lemmas
import Init.Data.List.Count
import Init.Data.Subtype
namespace List

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@@ -0,0 +1,242 @@
/-
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.Sublist
/-!
# Lemmas about `List.countP` and `List.count`.
-/
namespace List
open Nat
/-! ### countP -/
section countP
variable (p q : α Bool)
@[simp] theorem countP_nil : countP p [] = 0 := rfl
protected theorem countP_go_eq_add (l) : countP.go p l n = n + countP.go p l 0 := by
induction l generalizing n with
| nil => rfl
| cons head tail ih =>
unfold countP.go
rw [ih (n := n + 1), ih (n := n), ih (n := 1)]
if h : p head then simp [h, Nat.add_assoc] else simp [h]
@[simp] theorem countP_cons_of_pos (l) (pa : p a) : countP p (a :: l) = countP p l + 1 := by
have : countP.go p (a :: l) 0 = countP.go p l 1 := show cond .. = _ by rw [pa]; rfl
unfold countP
rw [this, Nat.add_comm, List.countP_go_eq_add]
@[simp] theorem countP_cons_of_neg (l) (pa : ¬p a) : countP p (a :: l) = countP p l := by
simp [countP, countP.go, pa]
theorem countP_cons (a : α) (l) : countP p (a :: l) = countP p l + if p a then 1 else 0 := by
by_cases h : p a <;> simp [h]
theorem length_eq_countP_add_countP (l) : length l = countP p l + countP (fun a => ¬p a) l := by
induction l with
| nil => rfl
| cons x h ih =>
if h : p x then
rw [countP_cons_of_pos _ _ h, countP_cons_of_neg _ _ _, length, ih]
· rw [Nat.add_assoc, Nat.add_comm _ 1, Nat.add_assoc]
· simp only [h, not_true_eq_false, decide_False, not_false_eq_true]
else
rw [countP_cons_of_pos (fun a => ¬p a) _ _, countP_cons_of_neg _ _ h, length, ih]
· rfl
· simp only [h, not_false_eq_true, decide_True]
theorem countP_eq_length_filter (l) : countP p l = length (filter p l) := by
induction l with
| nil => rfl
| cons x l ih =>
if h : p x
then rw [countP_cons_of_pos p l h, ih, filter_cons_of_pos h, length]
else rw [countP_cons_of_neg p l h, ih, filter_cons_of_neg h]
theorem countP_le_length : countP p l l.length := by
simp only [countP_eq_length_filter]
apply length_filter_le
@[simp] theorem countP_append (l₁ l₂) : countP p (l₁ ++ l₂) = countP p l₁ + countP p l₂ := by
simp only [countP_eq_length_filter, filter_append, length_append]
theorem countP_pos : 0 < countP p l a l, p a := by
simp only [countP_eq_length_filter, length_pos_iff_exists_mem, mem_filter, exists_prop]
theorem countP_eq_zero : countP p l = 0 a l, ¬p a := by
simp only [countP_eq_length_filter, length_eq_zero, filter_eq_nil]
theorem countP_eq_length : countP p l = l.length a l, p a := by
rw [countP_eq_length_filter, filter_length_eq_length]
theorem Sublist.countP_le (s : l₁ <+ l₂) : countP p l₁ countP p l₂ := by
simp only [countP_eq_length_filter]
apply s.filter _ |>.length_le
theorem countP_filter (l : List α) :
countP p (filter q l) = countP (fun a => p a q a) l := by
simp only [countP_eq_length_filter, filter_filter]
@[simp] theorem countP_true {l : List α} : (l.countP fun _ => true) = l.length := by
rw [countP_eq_length]
simp
@[simp] theorem countP_false {l : List α} : (l.countP fun _ => false) = 0 := by
rw [countP_eq_zero]
simp
@[simp] theorem countP_map (p : β Bool) (f : α β) :
l, countP p (map f l) = countP (p f) l
| [] => rfl
| a :: l => by rw [map_cons, countP_cons, countP_cons, countP_map p f l]; rfl
variable {p q}
theorem countP_mono_left (h : x l, p x q x) : countP p l countP q l := by
induction l with
| nil => apply Nat.le_refl
| cons a l ihl =>
rw [forall_mem_cons] at h
have ha, hl := h
simp [countP_cons]
cases h : p a
· simp only [Bool.false_eq_true, reduceIte, Nat.add_zero]
apply Nat.le_trans ?_ (Nat.le_add_right _ _)
apply ihl hl
· simp only [reduceIte, ha h, succ_le_succ_iff]
apply ihl hl
theorem countP_congr (h : x l, p x q x) : countP p l = countP q l :=
Nat.le_antisymm
(countP_mono_left fun x hx => (h x hx).1)
(countP_mono_left fun x hx => (h x hx).2)
end countP
/-! ### count -/
section count
variable [BEq α]
@[simp] theorem count_nil (a : α) : count a [] = 0 := rfl
theorem count_cons (a b : α) (l : List α) :
count a (b :: l) = count a l + if b == a then 1 else 0 := by
simp [count, countP_cons]
theorem count_tail : (l : List α) (a : α) (h : l []),
l.tail.count a = l.count a - if l.head h == a then 1 else 0
| head :: tail, a, _ => by simp [count_cons]
theorem count_le_length (a : α) (l : List α) : count a l l.length := countP_le_length _
theorem Sublist.count_le (h : l₁ <+ l₂) (a : α) : count a l₁ count a l₂ := h.countP_le _
theorem count_le_count_cons (a b : α) (l : List α) : count a l count a (b :: l) :=
(sublist_cons_self _ _).count_le _
theorem count_singleton (a b : α) : count a [b] = if b == a then 1 else 0 := by
simp [count_cons]
@[simp] theorem count_append (a : α) : l₁ l₂, count a (l₁ ++ l₂) = count a l₁ + count a l₂ :=
countP_append _
variable [LawfulBEq α]
@[simp] theorem count_cons_self (a : α) (l : List α) : count a (a :: l) = count a l + 1 := by
simp [count_cons]
@[simp] theorem count_cons_of_ne (h : a b) (l : List α) : count a (b :: l) = count a l := by
simp only [count_cons, cond_eq_if, beq_iff_eq]
split <;> simp_all
theorem count_singleton_self (a : α) : count a [a] = 1 := by simp
theorem count_concat_self (a : α) (l : List α) :
count a (concat l a) = (count a l) + 1 := by simp
@[simp]
theorem count_pos_iff_mem {a : α} {l : List α} : 0 < count a l a l := by
simp only [count, countP_pos, beq_iff_eq, exists_eq_right]
theorem count_eq_zero_of_not_mem {a : α} {l : List α} (h : a l) : count a l = 0 :=
Decidable.byContradiction fun h' => h <| count_pos_iff_mem.1 (Nat.pos_of_ne_zero h')
theorem not_mem_of_count_eq_zero {a : α} {l : List α} (h : count a l = 0) : a l :=
fun h' => Nat.ne_of_lt (count_pos_iff_mem.2 h') h.symm
theorem count_eq_zero {l : List α} : count a l = 0 a l :=
not_mem_of_count_eq_zero, count_eq_zero_of_not_mem
theorem count_eq_length {l : List α} : count a l = l.length b l, a = b := by
rw [count, countP_eq_length]
refine fun h b hb => Eq.symm ?_, fun h b hb => ?_
· simpa using h b hb
· rw [h b hb, beq_self_eq_true]
@[simp] theorem count_replicate_self (a : α) (n : Nat) : count a (replicate n a) = n :=
(count_eq_length.2 <| fun _ h => (eq_of_mem_replicate h).symm).trans (length_replicate ..)
theorem count_replicate (a b : α) (n : Nat) : count a (replicate n b) = if b == a then n else 0 := by
split <;> (rename_i h; simp only [beq_iff_eq] at h)
· exact b = a count_replicate_self ..
· exact count_eq_zero.2 <| mt eq_of_mem_replicate (Ne.symm h)
theorem filter_beq (l : List α) (a : α) : l.filter (· == a) = replicate (count a l) a := by
simp only [count, countP_eq_length_filter, eq_replicate, mem_filter, beq_iff_eq]
exact trivial, fun _ h => h.2
theorem filter_eq {α} [DecidableEq α] (l : List α) (a : α) : l.filter (· = a) = replicate (count a l) a :=
filter_beq l a
theorem le_count_iff_replicate_sublist {l : List α} : n count a l replicate n a <+ l := by
refine fun h => ?_, fun h => ?_
· exact ((replicate_sublist_replicate a).2 h).trans <| filter_beq l a filter_sublist _
· simpa only [count_replicate_self] using h.count_le a
theorem replicate_count_eq_of_count_eq_length {l : List α} (h : count a l = length l) :
replicate (count a l) a = l :=
(le_count_iff_replicate_sublist.mp (Nat.le_refl _)).eq_of_length <|
(length_replicate (count a l) a).trans h
@[simp] theorem count_filter {l : List α} (h : p a) : count a (filter p l) = count a l := by
rw [count, countP_filter]; congr; funext b
simp; rintro rfl; exact h
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 (config := { contextual := true })
theorem count_erase (a b : α) :
l : List α, count a (l.erase b) = count a l - if b == a then 1 else 0
| [] => by simp
| c :: l => by
rw [erase_cons]
if hc : c = b then
have hc_beq := (beq_iff_eq _ _).mpr hc
rw [if_pos hc_beq, hc, count_cons, Nat.add_sub_cancel]
else
have hc_beq := beq_false_of_ne hc
simp only [hc_beq, if_false, count_cons, count_cons, count_erase a b l]
if ha : b = a then
rw [ha, eq_comm] at hc
rw [if_pos ((beq_iff_eq _ _).2 ha), if_neg (by simpa using Ne.symm hc), Nat.add_zero, Nat.add_zero]
else
rw [if_neg (by simpa using ha), Nat.sub_zero, Nat.sub_zero]
@[simp] theorem count_erase_self (a : α) (l : List α) :
count a (List.erase l a) = count a l - 1 := by rw [count_erase, if_pos (by simp)]
@[simp] theorem count_erase_of_ne (ab : a b) (l : List α) : count a (l.erase b) = count a l := by
rw [count_erase, if_neg (by simpa using ab.symm), Nat.sub_zero]
end count

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@@ -0,0 +1,445 @@
/-
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,
Yury Kudryashov
-/
prelude
import Init.Data.List.Pairwise
/-!
# Lemmas about `List.eraseP` and `List.erase`.
-/
namespace List
open Nat
/-! ### eraseP -/
@[simp] theorem eraseP_nil : [].eraseP p = [] := rfl
theorem eraseP_cons (a : α) (l : List α) :
(a :: l).eraseP p = bif p a then l else a :: l.eraseP p := rfl
@[simp] theorem eraseP_cons_of_pos {l : List α} {p} (h : p a) : (a :: l).eraseP p = l := by
simp [eraseP_cons, h]
@[simp] theorem eraseP_cons_of_neg {l : List α} {p} (h : ¬p a) :
(a :: l).eraseP p = a :: l.eraseP p := by simp [eraseP_cons, h]
theorem eraseP_of_forall_not {l : List α} (h : a, a l ¬p a) : l.eraseP p = l := by
induction l with
| nil => rfl
| cons _ _ ih => simp [h _ (.head ..), ih (forall_mem_cons.1 h).2]
theorem exists_of_eraseP : {l : List α} {a} (al : a l) (pa : p a),
a l₁ l₂, ( b l₁, ¬p b) p a l = l₁ ++ a :: l₂ l.eraseP p = l₁ ++ l₂
| b :: l, a, al, pa =>
if pb : p b then
b, [], l, forall_mem_nil _, pb, by simp [pb]
else
match al with
| .head .. => nomatch pb pa
| .tail _ al =>
let c, l₁, l₂, h₁, h₂, h₃, h₄ := exists_of_eraseP al pa
c, b::l₁, l₂, (forall_mem_cons ..).2 pb, h₁,
h₂, by rw [h₃, cons_append], by simp [pb, h₄]
theorem exists_or_eq_self_of_eraseP (p) (l : List α) :
l.eraseP p = l
a l₁ l₂, ( b l₁, ¬p b) p a l = l₁ ++ a :: l₂ l.eraseP p = l₁ ++ l₂ :=
if h : a l, p a then
let _, ha, pa := h
.inr (exists_of_eraseP ha pa)
else
.inl (eraseP_of_forall_not (h ·, ·, ·))
@[simp] theorem length_eraseP_of_mem (al : a l) (pa : p a) :
length (l.eraseP p) = length l - 1 := by
let _, l₁, l₂, _, _, e₁, e₂ := exists_of_eraseP al pa
rw [e₂]; simp [length_append, e₁]; rfl
theorem length_eraseP {l : List α} : (l.eraseP p).length = if l.any p then l.length - 1 else l.length := by
split <;> rename_i h
· simp only [any_eq_true] at h
obtain x, m, h := h
simp [length_eraseP_of_mem m h]
· simp only [any_eq_true] at h
rw [eraseP_of_forall_not]
simp_all
theorem eraseP_sublist (l : List α) : l.eraseP p <+ l := by
match exists_or_eq_self_of_eraseP p l with
| .inl h => rw [h]; apply Sublist.refl
| .inr c, l₁, l₂, _, _, h₃, h₄ => rw [h₄, h₃]; simp
theorem eraseP_subset (l : List α) : l.eraseP p l := (eraseP_sublist l).subset
protected theorem Sublist.eraseP : l₁ <+ l₂ l₁.eraseP p <+ l₂.eraseP p
| .slnil => Sublist.refl _
| .cons a s => by
by_cases h : p a
· simpa [h] using s.eraseP.trans (eraseP_sublist _)
· simpa [h] using s.eraseP.cons _
| .cons₂ a s => by
by_cases h : p a
· simpa [h] using s
· simpa [h] using s.eraseP
theorem length_eraseP_le (l : List α) : (l.eraseP p).length l.length :=
l.eraseP_sublist.length_le
theorem mem_of_mem_eraseP {l : List α} : a l.eraseP p a l := (eraseP_subset _ ·)
@[simp] theorem mem_eraseP_of_neg {l : List α} (pa : ¬p a) : a l.eraseP p a l := by
refine mem_of_mem_eraseP, fun al => ?_
match exists_or_eq_self_of_eraseP p l with
| .inl h => rw [h]; assumption
| .inr c, l₁, l₂, h₁, h₂, h₃, h₄ =>
rw [h₄]; rw [h₃] at al
have : a c := fun h => (h pa).elim h₂
simp [this] at al; simp [al]
@[simp] theorem eraseP_eq_self_iff {p} {l : List α} : l.eraseP p = l a l, ¬ p a := by
rw [ Sublist.length_eq (eraseP_sublist l), length_eraseP]
split <;> rename_i h
· simp only [any_eq_true, length_eq_zero] at h
constructor
· intro; simp_all [Nat.sub_one_eq_self]
· intro; obtain x, m, h := h; simp_all
· simp_all
theorem eraseP_map (f : β α) : (l : List β), (map f l).eraseP p = map f (l.eraseP (p f))
| [] => rfl
| b::l => by by_cases h : p (f b) <;> simp [h, eraseP_map f l, eraseP_cons_of_pos]
theorem eraseP_filterMap (f : α Option β) : (l : List α),
(filterMap f l).eraseP p = filterMap f (l.eraseP (fun x => match f x with | some y => p y | none => false))
| [] => rfl
| a::l => by
rw [filterMap_cons, eraseP_cons]
split <;> rename_i h
· simp [h, eraseP_filterMap]
· rename_i b
rw [h, eraseP_cons]
by_cases w : p b
· simp [w]
· simp only [w, cond_false]
rw [filterMap_cons_some h, eraseP_filterMap]
theorem eraseP_filter (f : α Bool) (l : List α) :
(filter f l).eraseP p = filter f (l.eraseP (fun x => p x && f x)) := by
rw [ filterMap_eq_filter, eraseP_filterMap]
congr
ext x
simp only [Option.guard]
split <;> split at * <;> simp_all
theorem eraseP_append_left {a : α} (pa : p a) :
{l₁ : List α} l₂, a l₁ (l₁++l₂).eraseP p = l₁.eraseP p ++ l₂
| x :: xs, l₂, h => by
by_cases h' : p x <;> simp [h']
rw [eraseP_append_left pa l₂ ((mem_cons.1 h).resolve_left (mt _ h'))]
intro | rfl => exact pa
theorem eraseP_append_right :
{l₁ : List α} l₂, ( b l₁, ¬p b) eraseP p (l₁++l₂) = l₁ ++ l₂.eraseP p
| [], l₂, _ => rfl
| x :: xs, l₂, h => by
simp [(forall_mem_cons.1 h).1, eraseP_append_right _ (forall_mem_cons.1 h).2]
theorem eraseP_append (l₁ l₂ : List α) :
(l₁ ++ l₂).eraseP p = if l₁.any p then l₁.eraseP p ++ l₂ else l₁ ++ l₂.eraseP p := by
split <;> rename_i h
· simp only [any_eq_true] at h
obtain x, m, h := h
rw [eraseP_append_left h _ m]
· simp only [any_eq_true] at h
rw [eraseP_append_right _]
simp_all
theorem eraseP_eq_iff {p} {l : List α} :
l.eraseP p = l'
(( a l, ¬ p a) l = l')
a l₁ l₂, ( b l₁, ¬ p b) p a l = l₁ ++ a :: l₂ l' = l₁ ++ l₂ := by
cases exists_or_eq_self_of_eraseP p l with
| inl h =>
constructor
· intro h'
left
exact eraseP_eq_self_iff.1 h, by simp_all
· rintro (-, rfl | a, l₁, l₂, h₁, h₂, rfl, rfl)
· assumption
· rw [eraseP_append_right _ h₁, eraseP_cons_of_pos h₂]
| inr h =>
obtain a, l₁, l₂, h₁, h₂, w₁, w₂ := h
rw [w₂]
subst w₁
constructor
· rintro rfl
right
refine a, l₁, l₂, ?_
simp_all
· rintro (h | h)
· simp_all
· obtain a', l₁', l₂', h₁', h₂', h, rfl := h
have p : l₁ = l₁' := by
have q : l₁ = takeWhile (fun x => !p x) (l₁ ++ a :: l₂) := by
rw [takeWhile_append_of_pos (by simp_all),
takeWhile_cons_of_neg (by simp [h₂]), append_nil]
have q' : l₁' = takeWhile (fun x => !p x) (l₁' ++ a' :: l₂') := by
rw [takeWhile_append_of_pos (by simpa using h₁'),
takeWhile_cons_of_neg (by simp [h₂']), append_nil]
simp [h] at q
rw [q', q]
subst p
simp_all
@[simp] theorem eraseP_replicate_of_pos {n : Nat} {a : α} (h : p a) :
(replicate n a).eraseP p = replicate (n - 1) a := by
cases n <;> simp [replicate_succ, h]
@[simp] theorem eraseP_replicate_of_neg {n : Nat} {a : α} (h : ¬p a) :
(replicate n a).eraseP p = replicate n a := by
rw [eraseP_of_forall_not (by simp_all)]
theorem Nodup.eraseP (p) : Nodup l Nodup (l.eraseP p) :=
Nodup.sublist <| eraseP_sublist _
theorem eraseP_comm {l : List α} (h : a l, ¬ p a ¬ q a) :
(l.eraseP p).eraseP q = (l.eraseP q).eraseP p := by
induction l with
| nil => rfl
| cons a l ih =>
simp only [eraseP_cons]
by_cases h₁ : p a
· by_cases h₂ : q a
· simp_all
· simp [h₁, h₂, ih (fun b m => h b (mem_cons_of_mem _ m))]
· by_cases h₂ : q a
· simp [h₁, h₂, ih (fun b m => h b (mem_cons_of_mem _ m))]
· simp [h₁, h₂, ih (fun b m => h b (mem_cons_of_mem _ m))]
/-! ### erase -/
section erase
variable [BEq α]
@[simp] theorem erase_cons_head [LawfulBEq α] (a : α) (l : List α) : (a :: l).erase a = l := by
simp [erase_cons]
@[simp] theorem erase_cons_tail {a b : α} {l : List α} (h : ¬(b == a)) :
(b :: l).erase a = b :: l.erase a := by simp only [erase_cons, if_neg h]
theorem erase_of_not_mem [LawfulBEq α] {a : α} : {l : List α}, a l l.erase a = l
| [], _ => rfl
| b :: l, h => by
rw [mem_cons, not_or] at h
simp only [erase_cons, if_neg, erase_of_not_mem h.2, beq_iff_eq, Ne.symm h.1, not_false_eq_true]
theorem erase_eq_eraseP' (a : α) (l : List α) : l.erase a = l.eraseP (· == a) := by
induction l
· simp
· next b t ih =>
rw [erase_cons, eraseP_cons, ih]
if h : b == a then simp [h] else simp [h]
theorem erase_eq_eraseP [LawfulBEq α] (a : α) : l : List α, l.erase a = l.eraseP (a == ·)
| [] => rfl
| b :: l => by
if h : a = b then simp [h] else simp [h, Ne.symm h, erase_eq_eraseP a l]
theorem exists_erase_eq [LawfulBEq α] {a : α} {l : List α} (h : a l) :
l₁ l₂, a l₁ l = l₁ ++ a :: l₂ l.erase a = l₁ ++ l₂ := by
let _, l₁, l₂, h₁, e, h₂, h₃ := exists_of_eraseP h (beq_self_eq_true _)
rw [erase_eq_eraseP]; exact l₁, l₂, fun h => h₁ _ h (beq_self_eq_true _), eq_of_beq e h₂, h₃
@[simp] theorem length_erase_of_mem [LawfulBEq α] {a : α} {l : List α} (h : a l) :
length (l.erase a) = length l - 1 := by
rw [erase_eq_eraseP]; exact length_eraseP_of_mem h (beq_self_eq_true a)
theorem length_erase [LawfulBEq α] (a : α) (l : List α) :
length (l.erase a) = if a l then length l - 1 else length l := by
rw [erase_eq_eraseP, length_eraseP]
split <;> split <;> simp_all
theorem erase_sublist (a : α) (l : List α) : l.erase a <+ l :=
erase_eq_eraseP' a l eraseP_sublist ..
theorem erase_subset (a : α) (l : List α) : l.erase a l := (erase_sublist a l).subset
theorem Sublist.erase (a : α) {l₁ l₂ : List α} (h : l₁ <+ l₂) : l₁.erase a <+ l₂.erase a := by
simp only [erase_eq_eraseP']; exact h.eraseP
theorem length_erase_le (a : α) (l : List α) : (l.erase a).length l.length :=
(erase_sublist a l).length_le
theorem mem_of_mem_erase {a b : α} {l : List α} (h : a l.erase b) : a l := erase_subset _ _ h
@[simp] theorem mem_erase_of_ne [LawfulBEq α] {a b : α} {l : List α} (ab : a b) :
a l.erase b a l :=
erase_eq_eraseP b l mem_eraseP_of_neg (mt eq_of_beq ab.symm)
@[simp] theorem erase_eq_self_iff [LawfulBEq α] {l : List α} : l.erase a = l a l := by
rw [erase_eq_eraseP', eraseP_eq_self_iff]
simp
theorem erase_filter [LawfulBEq α] (f : α Bool) (l : List α) :
(filter f l).erase a = filter f (l.erase a) := by
induction l with
| nil => rfl
| cons x xs ih =>
by_cases h : a = x
· rw [erase_cons]
simp only [h, beq_self_eq_true, reduceIte]
rw [filter_cons]
split
· rw [erase_cons_head]
· rw [erase_of_not_mem]
simp_all [mem_filter]
· rw [erase_cons_tail (by simpa using Ne.symm h), filter_cons, filter_cons]
split
· rw [erase_cons_tail (by simpa using Ne.symm h), ih]
· rw [ih]
theorem erase_append_left [LawfulBEq α] {l₁ : List α} (l₂) (h : a l₁) :
(l₁ ++ l₂).erase a = l₁.erase a ++ l₂ := by
simp [erase_eq_eraseP]; exact eraseP_append_left (beq_self_eq_true a) l₂ h
theorem erase_append_right [LawfulBEq α] {a : α} {l₁ : List α} (l₂ : List α) (h : a l₁) :
(l₁ ++ l₂).erase a = (l₁ ++ l₂.erase a) := by
rw [erase_eq_eraseP, erase_eq_eraseP, eraseP_append_right]
intros b h' h''; rw [eq_of_beq h''] at h; exact h h'
theorem erase_append [LawfulBEq α] {a : α} {l₁ l₂ : List α} :
(l₁ ++ l₂).erase a = if a l₁ then l₁.erase a ++ l₂ else l₁ ++ l₂.erase a := by
simp [erase_eq_eraseP, eraseP_append]
theorem erase_comm [LawfulBEq α] (a b : α) (l : List α) :
(l.erase a).erase b = (l.erase b).erase a := by
if ab : a == b then rw [eq_of_beq ab] else ?_
if ha : a l then ?_ else
simp only [erase_of_not_mem ha, erase_of_not_mem (mt mem_of_mem_erase ha)]
if hb : b l then ?_ else
simp only [erase_of_not_mem hb, erase_of_not_mem (mt mem_of_mem_erase hb)]
match l, l.erase a, exists_erase_eq ha with
| _, _, l₁, l₂, ha', rfl, rfl =>
if h₁ : b l₁ then
rw [erase_append_left _ h₁, erase_append_left _ h₁,
erase_append_right _ (mt mem_of_mem_erase ha'), erase_cons_head]
else
rw [erase_append_right _ h₁, erase_append_right _ h₁, erase_append_right _ ha',
erase_cons_tail ab, erase_cons_head]
theorem erase_eq_iff [LawfulBEq α] {a : α} {l : List α} :
l.erase a = l'
(a l l = l')
l₁ l₂, a l₁ l = l₁ ++ a :: l₂ l' = l₁ ++ l₂ := by
rw [erase_eq_eraseP', eraseP_eq_iff]
simp only [beq_iff_eq, forall_mem_ne', exists_and_left]
constructor
· rintro (h, rfl | a', l', h, rfl, x, rfl, rfl)
· left; simp_all
· right; refine l', h, x, by simp
· rintro (h, rfl | l₁, h, x, rfl, rfl)
· left; simp_all
· right; refine a, l₁, h, by simp
@[simp] theorem erase_replicate_self [LawfulBEq α] {a : α} :
(replicate n a).erase a = replicate (n - 1) a := by
cases n <;> simp [replicate_succ]
@[simp] theorem erase_replicate_ne [LawfulBEq α] {a b : α} (h : !b == a) :
(replicate n a).erase b = replicate n a := by
rw [erase_of_not_mem]
simp_all
theorem Nodup.erase_eq_filter [BEq α] [LawfulBEq α] {l} (d : Nodup l) (a : α) : l.erase a = l.filter (· != a) := by
induction d with
| nil => rfl
| cons m _n ih =>
rename_i b l
by_cases h : b = a
· subst h
rw [erase_cons_head, filter_cons_of_neg (by simp)]
apply Eq.symm
rw [filter_eq_self]
simpa [@eq_comm α] using m
· simp [beq_false_of_ne h, ih, h]
theorem Nodup.mem_erase_iff [BEq α] [LawfulBEq α] {a : α} (d : Nodup l) : a l.erase b a b a l := by
rw [Nodup.erase_eq_filter d, mem_filter, and_comm, bne_iff_ne]
theorem Nodup.not_mem_erase [BEq α] [LawfulBEq α] {a : α} (h : Nodup l) : a l.erase a := fun H => by
simpa using ((Nodup.mem_erase_iff h).mp H).left
theorem Nodup.erase [BEq α] [LawfulBEq α] (a : α) : Nodup l Nodup (l.erase a) :=
Nodup.sublist <| erase_sublist _ _
end erase
/-! ### eraseIdx -/
theorem length_eraseIdx : {l i}, i < length l length (@eraseIdx α l i) = length l - 1
| [], _, _ => rfl
| _::_, 0, _ => by simp [eraseIdx]
| x::xs, i+1, h => by
have : i < length xs := Nat.lt_of_succ_lt_succ h
simp [eraseIdx, Nat.add_one]
rw [length_eraseIdx this, Nat.sub_add_cancel (Nat.lt_of_le_of_lt (Nat.zero_le _) this)]
@[simp] theorem eraseIdx_zero (l : List α) : eraseIdx l 0 = tail l := by cases l <;> rfl
theorem eraseIdx_eq_take_drop_succ :
(l : List α) (i : Nat), l.eraseIdx i = l.take i ++ l.drop (i + 1)
| nil, _ => by simp
| a::l, 0 => by simp
| a::l, i + 1 => by simp [eraseIdx_eq_take_drop_succ l i]
theorem eraseIdx_sublist : (l : List α) (k : Nat), eraseIdx l k <+ l
| [], _ => by simp
| a::l, 0 => by simp
| a::l, k + 1 => by simp [eraseIdx_sublist l k]
theorem eraseIdx_subset (l : List α) (k : Nat) : eraseIdx l k l := (eraseIdx_sublist l k).subset
@[simp]
theorem eraseIdx_eq_self : {l : List α} {k : Nat}, eraseIdx l k = l length l k
| [], _ => by simp
| a::l, 0 => by simp [(cons_ne_self _ _).symm]
| a::l, k + 1 => by simp [eraseIdx_eq_self]
theorem eraseIdx_of_length_le {l : List α} {k : Nat} (h : length l k) : eraseIdx l k = l := by
rw [eraseIdx_eq_self.2 h]
theorem eraseIdx_append_of_lt_length {l : List α} {k : Nat} (hk : k < length l) (l' : List α) :
eraseIdx (l ++ l') k = eraseIdx l k ++ l' := by
induction l generalizing k with
| nil => simp_all
| cons x l ih =>
cases k with
| zero => rfl
| succ k => simp_all [eraseIdx_cons_succ, Nat.succ_lt_succ_iff]
theorem eraseIdx_append_of_length_le {l : List α} {k : Nat} (hk : length l k) (l' : List α) :
eraseIdx (l ++ l') k = l ++ eraseIdx l' (k - length l) := by
induction l generalizing k with
| nil => simp_all
| cons x l ih =>
cases k with
| zero => simp_all
| succ k => simp_all [eraseIdx_cons_succ, Nat.succ_sub_succ]
protected theorem IsPrefix.eraseIdx {l l' : List α} (h : l <+: l') (k : Nat) :
eraseIdx l k <+: eraseIdx l' k := by
rcases h with t, rfl
if hkl : k < length l then
simp [eraseIdx_append_of_lt_length hkl]
else
rw [Nat.not_lt] at hkl
simp [eraseIdx_append_of_length_le hkl, eraseIdx_of_length_le hkl]
-- See also `mem_eraseIdx_iff_getElem` and `mem_eraseIdx_iff_getElem?` in
-- `Init/Data/List/Nat/Basic.lean`.
end List

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/-
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.Lemmas
/-!
# Lemmas about `List.find?`, `List.findSome?`, `List.findIdx`, `List.findIdx?`, and `List.indexOf`.
-/
namespace List
open Nat
/-! ### find? -/
@[simp] theorem find?_cons_of_pos (l) (h : p a) : find? p (a :: l) = some a := by
simp [find?, h]
@[simp] theorem find?_cons_of_neg (l) (h : ¬p a) : find? p (a :: l) = find? p l := by
simp [find?, h]
@[simp] theorem find?_eq_none : find? p l = none x l, ¬ p x := by
induction l <;> simp [find?_cons]; split <;> simp [*]
theorem find?_some : {l}, find? p l = some a p a
| b :: l, H => by
by_cases h : p b <;> simp [find?, h] at H
· exact H h
· exact find?_some H
@[simp] theorem mem_of_find?_eq_some : {l}, find? p l = some a a l
| b :: l, H => by
by_cases h : p b <;> simp [find?, h] at H
· exact H .head _
· exact .tail _ (mem_of_find?_eq_some H)
@[simp] theorem find?_map (f : β α) (l : List β) : find? p (l.map f) = (l.find? (p f)).map f := by
induction l with
| nil => simp
| cons x xs ih =>
simp only [map_cons, find?]
by_cases h : p (f x) <;> simp [h, ih]
theorem find?_replicate : find? p (replicate n a) = if n = 0 then none else if p a then some a else none := by
cases n
· simp
· by_cases p a <;> simp_all [replicate_succ]
@[simp] theorem find?_replicate_of_length_pos (h : 0 < n) : find? p (replicate n a) = if p a then some a else none := by
simp [find?_replicate, Nat.ne_of_gt h]
@[simp] theorem find?_replicate_of_pos (h : p a) : find? p (replicate n a) = if n = 0 then none else some a := by
simp [find?_replicate, h]
@[simp] theorem find?_replicate_of_neg (h : ¬ p a) : find? p (replicate n a) = none := by
simp [find?_replicate, h]
theorem find?_isSome_of_sublist {l₁ l₂ : List α} (h : l₁ <+ l₂) : (l₁.find? p).isSome (l₂.find? p).isSome := by
induction h with
| slnil => simp
| cons a h ih
| cons₂ a h ih =>
simp only [find?]
split <;> simp_all
/-! ### findSome? -/
@[simp] theorem findSome?_cons_of_isSome (l) (h : (f a).isSome) : findSome? f (a :: l) = f a := by
simp only [findSome?]
split <;> simp_all
@[simp] theorem findSome?_cons_of_isNone (l) (h : (f a).isNone) : findSome? f (a :: l) = findSome? f l := by
simp only [findSome?]
split <;> simp_all
theorem exists_of_findSome?_eq_some {l : List α} {f : α Option β} (w : l.findSome? f = some b) :
a, a l f a = b := by
induction l with
| nil => simp_all
| cons h l ih =>
simp_all only [findSome?_cons, mem_cons, exists_eq_or_imp]
split at w <;> simp_all
@[simp] theorem findSome?_map (f : β γ) (l : List β) : findSome? p (l.map f) = l.findSome? (p f) := by
induction l with
| nil => simp
| cons x xs ih =>
simp only [map_cons, findSome?]
split <;> simp_all
theorem findSome?_replicate : findSome? f (replicate n a) = if n = 0 then none else f a := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate_succ, findSome?_cons]
split <;> simp_all
@[simp] theorem findSome?_replicate_of_pos (h : 0 < n) : findSome? f (replicate n a) = f a := by
simp [findSome?_replicate, Nat.ne_of_gt h]
-- Argument is unused, but used to decide whether `simp` should unfold.
@[simp] theorem find?_replicate_of_isSome (_ : (f a).isSome) : findSome? f (replicate n a) = if n = 0 then none else f a := by
simp [findSome?_replicate]
@[simp] theorem find?_replicate_of_isNone (h : (f a).isNone) : findSome? f (replicate n a) = none := by
rw [Option.isNone_iff_eq_none] at h
simp [findSome?_replicate, h]
theorem findSome?_isSome_of_sublist {l₁ l₂ : List α} (h : l₁ <+ l₂) :
(l₁.findSome? f).isSome (l₂.findSome? f).isSome := by
induction h with
| slnil => simp
| cons a h ih
| cons₂ a h ih =>
simp only [findSome?]
split <;> simp_all
/-! ### findIdx -/
theorem findIdx_cons (p : α Bool) (b : α) (l : List α) :
(b :: l).findIdx p = bif p b then 0 else (l.findIdx p) + 1 := by
cases H : p b with
| true => simp [H, findIdx, findIdx.go]
| false => simp [H, findIdx, findIdx.go, findIdx_go_succ]
where
findIdx_go_succ (p : α Bool) (l : List α) (n : Nat) :
List.findIdx.go p l (n + 1) = (findIdx.go p l n) + 1 := by
cases l with
| nil => unfold findIdx.go; exact Nat.succ_eq_add_one n
| cons head tail =>
unfold findIdx.go
cases p head <;> simp only [cond_false, cond_true]
exact findIdx_go_succ p tail (n + 1)
theorem findIdx_of_get?_eq_some {xs : List α} (w : xs.get? (xs.findIdx p) = some y) : p y := by
induction xs with
| nil => simp_all
| cons x xs ih => by_cases h : p x <;> simp_all [findIdx_cons]
theorem findIdx_get {xs : List α} {w : xs.findIdx p < xs.length} :
p (xs.get xs.findIdx p, w) :=
xs.findIdx_of_get?_eq_some (get?_eq_get w)
theorem findIdx_lt_length_of_exists {xs : List α} (h : x xs, p x) :
xs.findIdx p < xs.length := by
induction xs with
| nil => simp_all
| cons x xs ih =>
by_cases p x
· simp_all only [forall_exists_index, and_imp, mem_cons, exists_eq_or_imp, true_or,
findIdx_cons, cond_true, length_cons]
apply Nat.succ_pos
· simp_all [findIdx_cons]
refine Nat.succ_lt_succ ?_
obtain x', m', h' := h
exact ih x' m' h'
theorem findIdx_get?_eq_get_of_exists {xs : List α} (h : x xs, p x) :
xs.get? (xs.findIdx p) = some (xs.get xs.findIdx p, xs.findIdx_lt_length_of_exists h) :=
get?_eq_get (findIdx_lt_length_of_exists h)
/-! ### findIdx? -/
@[simp] theorem findIdx?_nil : ([] : List α).findIdx? p i = none := rfl
@[simp] theorem findIdx?_cons :
(x :: xs).findIdx? p i = if p x then some i else findIdx? p xs (i + 1) := rfl
@[simp] theorem findIdx?_succ :
(xs : List α).findIdx? p (i+1) = (xs.findIdx? p i).map fun i => i + 1 := by
induction xs generalizing i with simp
| cons _ _ _ => split <;> simp_all
theorem findIdx?_eq_some_iff (xs : List α) (p : α Bool) :
xs.findIdx? p = some i (xs.take (i + 1)).map p = replicate i false ++ [true] := by
induction xs generalizing i with
| nil => simp
| cons x xs ih =>
simp only [findIdx?_cons, Nat.zero_add, findIdx?_succ, take_succ_cons, map_cons]
split <;> cases i <;> simp_all [replicate_succ, succ_inj']
theorem findIdx?_of_eq_some {xs : List α} {p : α Bool} (w : xs.findIdx? p = some i) :
match xs.get? i with | some a => p a | none => false := by
induction xs generalizing i with
| nil => simp_all
| cons x xs ih =>
simp_all only [findIdx?_cons, Nat.zero_add, findIdx?_succ]
split at w <;> cases i <;> simp_all [succ_inj']
theorem findIdx?_of_eq_none {xs : List α} {p : α Bool} (w : xs.findIdx? p = none) :
i, match xs.get? i with | some a => ¬ p a | none => true := by
intro i
induction xs generalizing i with
| nil => simp_all
| cons x xs ih =>
simp_all only [Bool.not_eq_true, findIdx?_cons, Nat.zero_add, findIdx?_succ]
cases i with
| zero =>
split at w <;> simp_all
| succ i =>
simp only [get?_cons_succ]
apply ih
split at w <;> simp_all
@[simp] theorem findIdx?_append :
(xs ++ ys : List α).findIdx? p =
(xs.findIdx? p <|> (ys.findIdx? p).map fun i => i + xs.length) := by
induction xs with simp
| cons _ _ _ => split <;> simp_all [Option.map_orElse, Option.map_map]; rfl
@[simp] theorem findIdx?_replicate :
(replicate n a).findIdx? p = if 0 < n p a then some 0 else none := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate, findIdx?_cons, Nat.zero_add, findIdx?_succ, Nat.zero_lt_succ, true_and]
split <;> simp_all
/-! ### indexOf -/
theorem indexOf_cons [BEq α] :
(x :: xs : List α).indexOf y = bif x == y then 0 else xs.indexOf y + 1 := by
dsimp [indexOf]
simp [findIdx_cons]
end List

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/-
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.Lemmas
/-!
# Lemmas about `List.minimum?` and `List.maximum?.
-/
namespace List
open Nat
/-! ## Minima and maxima -/
/-! ### minimum? -/
@[simp] theorem minimum?_nil [Min α] : ([] : List α).minimum? = none := rfl
-- We don't put `@[simp]` on `minimum?_cons`,
-- because the definition in terms of `foldl` is not useful for proofs.
theorem minimum?_cons [Min α] {xs : List α} : (x :: xs).minimum? = foldl min x xs := rfl
@[simp] theorem minimum?_eq_none_iff {xs : List α} [Min α] : xs.minimum? = none xs = [] := by
cases xs <;> simp [minimum?]
theorem minimum?_mem [Min α] (min_eq_or : a b : α, min a b = a min a b = b) :
{xs : List α} xs.minimum? = some a a xs := by
intro xs
match xs with
| nil => simp
| x :: xs =>
simp only [minimum?_cons, Option.some.injEq, List.mem_cons]
intro eq
induction xs generalizing x with
| nil =>
simp at eq
simp [eq]
| cons y xs ind =>
simp at eq
have p := ind _ eq
cases p with
| inl p =>
cases min_eq_or x y with | _ q => simp [p, q]
| inr p => simp [p, mem_cons]
-- See also `Init.Data.List.Nat.Basic` for specialisations of the next two results to `Nat`.
theorem le_minimum?_iff [Min α] [LE α]
(le_min_iff : a b c : α, a min b c a b a c) :
{xs : List α} xs.minimum? = some a x, x a b, b xs x b
| nil => by simp
| cons x xs => by
rw [minimum?]
intro eq y
simp only [Option.some.injEq] at eq
induction xs generalizing x with
| nil =>
simp at eq
simp [eq]
| cons z xs ih =>
simp at eq
simp [ih _ eq, le_min_iff, and_assoc]
-- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `min_eq_or`,
-- and `le_min_iff`.
theorem minimum?_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} :
xs.minimum? = some a a xs b, b xs a b := by
refine fun h => minimum?_mem min_eq_or h, (le_minimum?_iff le_min_iff h _).1 (le_refl _), ?_
intro h₁, h₂
cases xs with
| nil => simp at h₁
| cons x xs =>
exact congrArg some <| anti.1
((le_minimum?_iff le_min_iff (xs := x::xs) rfl _).1 (le_refl _) _ h₁)
(h₂ _ (minimum?_mem min_eq_or (xs := x::xs) rfl))
theorem minimum?_replicate [Min α] {n : Nat} {a : α} (w : min a a = a) :
(replicate n a).minimum? = if n = 0 then none else some a := by
induction n with
| zero => rfl
| succ n ih => cases n <;> simp_all [replicate_succ, minimum?_cons]
@[simp] theorem minimum?_replicate_of_pos [Min α] {n : Nat} {a : α} (w : min a a = a) (h : 0 < n) :
(replicate n a).minimum? = some a := by
simp [minimum?_replicate, Nat.ne_of_gt h, w]
/-! ### maximum? -/
@[simp] theorem maximum?_nil [Max α] : ([] : List α).maximum? = none := rfl
-- We don't put `@[simp]` on `maximum?_cons`,
-- because the definition in terms of `foldl` is not useful for proofs.
theorem maximum?_cons [Max α] {xs : List α} : (x :: xs).maximum? = foldl max x xs := rfl
@[simp] theorem maximum?_eq_none_iff {xs : List α} [Max α] : xs.maximum? = none xs = [] := by
cases xs <;> simp [maximum?]
theorem maximum?_mem [Max α] (min_eq_or : a b : α, max a b = a max a b = b) :
{xs : List α} xs.maximum? = some a a xs
| nil => by simp
| cons x xs => by
rw [maximum?]; rintro
induction xs generalizing x with simp at *
| cons y xs ih =>
rcases ih (max x y) with h | h <;> simp [h]
simp [ or_assoc, min_eq_or x y]
-- See also `Init.Data.List.Nat.Basic` for specialisations of the next two results to `Nat`.
theorem maximum?_le_iff [Max α] [LE α]
(max_le_iff : a b c : α, max b c a b a c a) :
{xs : List α} xs.maximum? = some a x, a x b xs, b x
| nil => by simp
| cons x xs => by
rw [maximum?]; rintro y
induction xs generalizing x with
| nil => simp
| cons y xs ih => simp [ih, max_le_iff, and_assoc]
-- This could be refactored by designing appropriate typeclasses to replace `le_refl`, `max_eq_or`,
-- and `le_min_iff`.
theorem maximum?_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} :
xs.maximum? = some a a xs b xs, b a := by
refine fun h => maximum?_mem max_eq_or h, (maximum?_le_iff max_le_iff h _).1 (le_refl _), ?_
intro h₁, h₂
cases xs with
| nil => simp at h₁
| cons x xs =>
exact congrArg some <| anti.1
(h₂ _ (maximum?_mem max_eq_or (xs := x::xs) rfl))
((maximum?_le_iff max_le_iff (xs := x::xs) rfl _).1 (le_refl _) _ h₁)
theorem maximum?_replicate [Max α] {n : Nat} {a : α} (w : max a a = a) :
(replicate n a).maximum? = if n = 0 then none else some a := by
induction n with
| zero => rfl
| succ n ih => cases n <;> simp_all [replicate_succ, maximum?_cons]
@[simp] theorem maximum?_replicate_of_pos [Max α] {n : Nat} {a : α} (w : max a a = a) (h : 0 < n) :
(replicate n a).maximum? = some a := by
simp [maximum?_replicate, Nat.ne_of_gt h, w]
end List

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/-
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.TakeDrop
/-!
# Lemmas about `List.mapM` and `List.forM`.
-/
namespace List
open Nat
/-! ## Monadic operations -/
-- We may want to replace these `simp` attributes with explicit equational lemmas,
-- as we already have for all the non-monadic functions.
attribute [simp] mapA forA filterAuxM firstM anyM allM findM? findSomeM?
-- Previously `mapM.loop`, `filterMapM.loop`, `forIn.loop`, `forIn'.loop`
-- had attribute `@[simp]`.
-- We don't currently provide simp lemmas,
-- as this is an internal implementation and they don't seem to be needed.
/-! ### mapM -/
/-- Alternate (non-tail-recursive) form of mapM for proofs. -/
def mapM' [Monad m] (f : α m β) : List α m (List β)
| [] => pure []
| a :: l => return ( f a) :: ( l.mapM' f)
@[simp] theorem mapM'_nil [Monad m] {f : α m β} : mapM' f [] = pure [] := rfl
@[simp] theorem mapM'_cons [Monad m] {f : α m β} :
mapM' f (a :: l) = return (( f a) :: ( l.mapM' f)) :=
rfl
theorem mapM'_eq_mapM [Monad m] [LawfulMonad m] (f : α m β) (l : List α) :
mapM' f l = mapM f l := by simp [go, mapM] where
go : l acc, mapM.loop f l acc = return acc.reverse ++ ( mapM' f l)
| [], acc => by simp [mapM.loop, mapM']
| a::l, acc => by simp [go l, mapM.loop, mapM']
@[simp] theorem mapM_nil [Monad m] (f : α m β) : [].mapM f = pure [] := rfl
@[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_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 [*]
/-! ### forM -/
-- We use `List.forM` as the simp normal form, rather that `ForM.forM`.
-- As such we need to replace `List.forM_nil` and `List.forM_cons`:
@[simp] theorem forM_nil' [Monad m] : ([] : List α).forM f = (pure .unit : m PUnit) := rfl
@[simp] theorem forM_cons' [Monad m] :
(a::as).forM f = (f a >>= fun _ => as.forM f : m PUnit) :=
List.forM_cons _ _ _
@[simp] theorem forM_append [Monad m] [LawfulMonad m] (l₁ l₂ : List α) (f : α m PUnit) :
(l₁ ++ l₂).forM f = (do l₁.forM f; l₂.forM f) := by
induction l₁ <;> simp [*]
end List

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@@ -1,93 +1,10 @@
/-
Copyright (c) 2014 Parikshit Khanna. All rights reserved.
Copyright (c) 2024 Lean FRO. 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
Authors: Kim Morrison
-/
prelude
import Init.Data.List.Lemmas
import Init.Data.Nat.Lemmas
/-!
# Miscellaneous `List` lemmas, that require more `Nat` lemmas than are available in `Init.Data.List.Lemmas`.
In particular, `omega` is available here.
-/
open Nat
namespace List
/-! ### filter -/
theorem length_filter_lt_length_iff_exists (l) :
length (filter p l) < length l x l, ¬p x := by
simpa [length_eq_countP_add_countP p l, countP_eq_length_filter] using
countP_pos (fun x => ¬p x) (l := l)
/-! ### minimum? -/
-- A specialization of `minimum?_eq_some_iff` to Nat.
theorem minimum?_eq_some_iff' {xs : List Nat} :
xs.minimum? = some a (a xs b xs, a b) :=
minimum?_eq_some_iff
(le_refl := Nat.le_refl)
(min_eq_or := fun _ _ => by omega)
(le_min_iff := fun _ _ _ => by omega)
-- This could be generalized,
-- but will first require further work on order typeclasses in the core repository.
theorem minimum?_cons' {a : Nat} {l : List Nat} :
(a :: l).minimum? = some (match l.minimum? with
| none => a
| some m => min a m) := by
rw [minimum?_eq_some_iff']
split <;> rename_i h m
· simp_all
· rw [minimum?_eq_some_iff'] at m
obtain m, le := m
rw [Nat.min_def]
constructor
· split
· exact mem_cons_self a l
· exact mem_cons_of_mem a m
· intro b m
cases List.mem_cons.1 m with
| inl => split <;> omega
| inr h =>
specialize le b h
split <;> omega
/-! ### maximum? -/
-- A specialization of `maximum?_eq_some_iff` to Nat.
theorem maximum?_eq_some_iff' {xs : List Nat} :
xs.maximum? = some a (a xs b xs, b a) :=
maximum?_eq_some_iff
(le_refl := Nat.le_refl)
(max_eq_or := fun _ _ => by omega)
(max_le_iff := fun _ _ _ => by omega)
-- This could be generalized,
-- but will first require further work on order typeclasses in the core repository.
theorem maximum?_cons' {a : Nat} {l : List Nat} :
(a :: l).maximum? = some (match l.maximum? with
| none => a
| some m => max a m) := by
rw [maximum?_eq_some_iff']
split <;> rename_i h m
· simp_all
· rw [maximum?_eq_some_iff'] at m
obtain m, le := m
rw [Nat.max_def]
constructor
· split
· exact mem_cons_of_mem a m
· exact mem_cons_self a l
· intro b m
cases List.mem_cons.1 m with
| inl => split <;> omega
| inr h =>
specialize le b h
split <;> omega
end List
import Init.Data.List.Nat.Basic
import Init.Data.List.Nat.Pairwise
import Init.Data.List.Nat.Range
import Init.Data.List.Nat.TakeDrop

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@@ -0,0 +1,125 @@
/-
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.Count
import Init.Data.List.MinMax
import Init.Data.Nat.Lemmas
/-!
# Miscellaneous `List` lemmas, that require more `Nat` lemmas than are available in `Init.Data.List.Lemmas`.
In particular, `omega` is available here.
-/
open Nat
namespace List
/-! ### filter -/
theorem length_filter_lt_length_iff_exists (l) :
length (filter p l) < length l x l, ¬p x := by
simpa [length_eq_countP_add_countP p l, countP_eq_length_filter] using
countP_pos (fun x => ¬p x) (l := l)
/-! ### leftpad -/
/-- The length of the List returned by `List.leftpad n a l` is equal
to the larger of `n` and `l.length` -/
@[simp]
theorem leftpad_length (n : Nat) (a : α) (l : List α) :
(leftpad n a l).length = max n l.length := by
simp only [leftpad, length_append, length_replicate, Nat.sub_add_eq_max]
/-! ### eraseIdx -/
theorem mem_eraseIdx_iff_getElem {x : α} :
{l} {k}, x eraseIdx l k i h, i k l[i]'h = x
| [], _ => by
simp only [eraseIdx, not_mem_nil, false_iff]
rintro i, h, -
exact Nat.not_lt_zero _ h
| a::l, 0 => by simp [mem_iff_getElem, Nat.succ_lt_succ_iff]
| a::l, k+1 => by
rw [ Nat.or_exists_add_one]
simp [mem_eraseIdx_iff_getElem, @eq_comm _ a, succ_inj', Nat.succ_lt_succ_iff]
theorem mem_eraseIdx_iff_getElem? {x : α} {l} {k} : x eraseIdx l k i k, l[i]? = some x := by
simp only [mem_eraseIdx_iff_getElem, getElem_eq_iff, exists_and_left]
refine exists_congr fun i => and_congr_right' ?_
constructor
· rintro _, h; exact h
· rintro h;
obtain h', - := getElem?_eq_some.1 h
exact h', h
/-! ### minimum? -/
-- A specialization of `minimum?_eq_some_iff` to Nat.
theorem minimum?_eq_some_iff' {xs : List Nat} :
xs.minimum? = some a (a xs b xs, a b) :=
minimum?_eq_some_iff
(le_refl := Nat.le_refl)
(min_eq_or := fun _ _ => by omega)
(le_min_iff := fun _ _ _ => by omega)
-- This could be generalized,
-- but will first require further work on order typeclasses in the core repository.
theorem minimum?_cons' {a : Nat} {l : List Nat} :
(a :: l).minimum? = some (match l.minimum? with
| none => a
| some m => min a m) := by
rw [minimum?_eq_some_iff']
split <;> rename_i h m
· simp_all
· rw [minimum?_eq_some_iff'] at m
obtain m, le := m
rw [Nat.min_def]
constructor
· split
· exact mem_cons_self a l
· exact mem_cons_of_mem a m
· intro b m
cases List.mem_cons.1 m with
| inl => split <;> omega
| inr h =>
specialize le b h
split <;> omega
/-! ### maximum? -/
-- A specialization of `maximum?_eq_some_iff` to Nat.
theorem maximum?_eq_some_iff' {xs : List Nat} :
xs.maximum? = some a (a xs b xs, b a) :=
maximum?_eq_some_iff
(le_refl := Nat.le_refl)
(max_eq_or := fun _ _ => by omega)
(max_le_iff := fun _ _ _ => by omega)
-- This could be generalized,
-- but will first require further work on order typeclasses in the core repository.
theorem maximum?_cons' {a : Nat} {l : List Nat} :
(a :: l).maximum? = some (match l.maximum? with
| none => a
| some m => max a m) := by
rw [maximum?_eq_some_iff']
split <;> rename_i h m
· simp_all
· rw [maximum?_eq_some_iff'] at m
obtain m, le := m
rw [Nat.max_def]
constructor
· split
· exact mem_cons_of_mem a m
· exact mem_cons_self a l
· intro b m
cases List.mem_cons.1 m with
| inl => split <;> omega
| inr h =>
specialize le b h
split <;> omega
end List

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/-
Copyright (c) 2018 Mario Carneiro. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Mario Carneiro, James Gallicchio
-/
prelude
import Init.Data.Fin.Lemmas
import Init.Data.List.Nat.TakeDrop
import Init.Data.List.Pairwise
/-!
# Lemmas about `List.Pairwise`
-/
namespace List
/-- Given a list `is` of monotonically increasing indices into `l`, getting each index
produces a sublist of `l`. -/
theorem map_getElem_sublist {l : List α} {is : List (Fin l.length)} (h : is.Pairwise (· < ·)) :
is.map (l[·]) <+ l := by
suffices n l', l' = l.drop n ( i is, n i) map (l[·]) is <+ l'
from this 0 l (by simp) (by simp)
rintro n l' rfl his
induction is generalizing n with
| nil => simp
| cons hd tl IH =>
simp only [Fin.getElem_fin, map_cons]
have := IH h.of_cons (hd+1) (pairwise_cons.mp h).1
specialize his hd (.head _)
have := (drop_eq_getElem_cons ..).symm this.cons₂ (get l hd)
have := Sublist.append (nil_sublist (take hd l |>.drop n)) this
rwa [nil_append, (drop_append_of_le_length ?_), take_append_drop] at this
simp [Nat.min_eq_left (Nat.le_of_lt hd.isLt), his]
@[deprecated map_getElem_sublist (since := "2024-07-30")]
theorem map_get_sublist {l : List α} {is : List (Fin l.length)} (h : is.Pairwise (·.val < ·.val)) :
is.map (get l) <+ l := by
simpa using map_getElem_sublist h
/-- Given a sublist `l' <+ l`, there exists an increasing list of indices `is` such that
`l' = is.map fun i => l[i]`. -/
theorem sublist_eq_map_getElem {l l' : List α} (h : l' <+ l) : is : List (Fin l.length),
l' = is.map (l[·]) is.Pairwise (· < ·) := by
induction h with
| slnil => exact [], by simp
| cons _ _ IH =>
let is, IH := IH
refine is.map (·.succ), ?_
simpa [Function.comp_def, pairwise_map]
| cons₂ _ _ IH =>
rcases IH with is,IH
refine 0, by simp [Nat.zero_lt_succ] :: is.map (·.succ), ?_
simp [Function.comp_def, pairwise_map, IH, get_eq_getElem]
@[deprecated sublist_eq_map_getElem (since := "2024-07-30")]
theorem sublist_eq_map_get (h : l' <+ l) : is : List (Fin l.length),
l' = map (get l) is is.Pairwise (· < ·) := by
simpa using sublist_eq_map_getElem h
theorem pairwise_iff_getElem : Pairwise R l
(i j : Nat) (_hi : i < l.length) (_hj : j < l.length) (_hij : i < j), R l[i] l[j] := by
rw [pairwise_iff_forall_sublist]
constructor <;> intro h
· intros i j hi hj h'
apply h
simpa [h'] using map_getElem_sublist (is := [i, hi, j, hj])
· intros a b h'
have is, h', hij := sublist_eq_map_getElem h'
rcases is with | a', | b', <;> simp at h'
rcases h' with rfl, rfl
apply h; simpa using hij
end List

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@@ -4,8 +4,8 @@ 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.TakeDrop
import Init.Data.Nat.Lemmas
import Init.Data.List.Nat.TakeDrop
import Init.Data.List.Pairwise
/-!
# Lemmas about `List.range` and `List.enum`

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@@ -0,0 +1,503 @@
/-
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.Zip
import Init.Data.Nat.Lemmas
/-!
# Further lemmas about `List.take`, `List.drop`, `List.zip` and `List.zipWith`.
These are in a separate file from most of the list lemmas
as they required importing more lemmas about natural numbers, and use `omega`.
-/
namespace List
open Nat
/-! ### take -/
@[simp] theorem length_take : (i : Nat) (l : List α), length (take i l) = min i (length l)
| 0, l => by simp [Nat.zero_min]
| succ n, [] => by simp [Nat.min_zero]
| succ n, _ :: l => by simp [Nat.succ_min_succ, length_take]
theorem length_take_le (n) (l : List α) : length (take n l) n := by simp [Nat.min_le_left]
theorem length_take_le' (n) (l : List α) : length (take n l) l.length :=
by simp [Nat.min_le_right]
theorem length_take_of_le (h : n length l) : length (take n l) = n := by simp [Nat.min_eq_left h]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the big list to the small list. -/
theorem getElem_take (L : List α) {i j : Nat} (hi : i < L.length) (hj : i < j) :
L[i] = (L.take j)[i]'(length_take .. Nat.lt_min.mpr hj, hi) :=
getElem_of_eq (take_append_drop j L).symm _ getElem_append ..
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the small list to the big list. -/
theorem getElem_take' (L : List α) {j i : Nat} {h : i < (L.take j).length} :
(L.take j)[i] =
L[i]'(Nat.lt_of_lt_of_le h (length_take_le' _ _)) := by
rw [length_take, Nat.lt_min] at h; rw [getElem_take L _ h.1]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the big list to the small list. -/
@[deprecated getElem_take (since := "2024-06-12")]
theorem get_take (L : List α) {i j : Nat} (hi : i < L.length) (hj : i < j) :
get L i, hi = get (L.take j) i, length_take .. Nat.lt_min.mpr hj, hi := by
simp [getElem_take _ hi hj]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the small list to the big list. -/
@[deprecated getElem_take (since := "2024-06-12")]
theorem get_take' (L : List α) {j i} :
get (L.take j) i =
get L i.1, Nat.lt_of_lt_of_le i.2 (length_take_le' _ _) := by
simp [getElem_take']
theorem getElem?_take_eq_none {l : List α} {n m : Nat} (h : n m) :
(l.take n)[m]? = none :=
getElem?_eq_none <| Nat.le_trans (length_take_le _ _) h
@[deprecated getElem?_take_eq_none (since := "2024-06-12")]
theorem get?_take_eq_none {l : List α} {n m : Nat} (h : n m) :
(l.take n).get? m = none := by
simp [getElem?_take_eq_none h]
theorem getElem?_take_eq_if {l : List α} {n m : Nat} :
(l.take n)[m]? = if m < n then l[m]? else none := by
split
· next h => exact getElem?_take h
· next h => exact getElem?_take_eq_none (Nat.le_of_not_lt h)
@[deprecated getElem?_take_eq_if (since := "2024-06-12")]
theorem get?_take_eq_if {l : List α} {n m : Nat} :
(l.take n).get? m = if m < n then l.get? m else none := by
simp [getElem?_take_eq_if]
theorem head?_take {l : List α} {n : Nat} :
(l.take n).head? = if n = 0 then none else l.head? := by
simp [head?_eq_getElem?, getElem?_take_eq_if]
split
· rw [if_neg (by omega)]
· rw [if_pos (by omega)]
theorem head_take {l : List α} {n : Nat} (h : l.take n []) :
(l.take n).head h = l.head (by simp_all) := by
apply Option.some_inj.1
rw [ head?_eq_head, head?_eq_head, head?_take, if_neg]
simp_all
theorem getLast?_take {l : List α} : (l.take n).getLast? = if n = 0 then none else l[n - 1]?.or l.getLast? := by
rw [getLast?_eq_getElem?, getElem?_take_eq_if, length_take]
split
· rw [if_neg (by omega)]
rw [Nat.min_def]
split
· rw [getElem?_eq_getElem (by omega)]
simp
· rw [ getLast?_eq_getElem?, getElem?_eq_none (by omega)]
simp
· rw [if_pos]
omega
theorem getLast_take {l : List α} (h : l.take n []) :
(l.take n).getLast h = l[n - 1]?.getD (l.getLast (by simp_all)) := by
rw [getLast_eq_getElem, getElem_take']
simp [length_take, Nat.min_def]
simp at h
split
· rw [getElem?_eq_getElem (by omega)]
simp
· rw [getElem?_eq_none (by omega), getLast_eq_getElem]
simp
theorem take_take : (n m) (l : List α), take n (take m l) = take (min n m) l
| n, 0, l => by rw [Nat.min_zero, take_zero, take_nil]
| 0, m, l => by rw [Nat.zero_min, take_zero, take_zero]
| succ n, succ m, nil => by simp only [take_nil]
| succ n, succ m, a :: l => by
simp only [take, succ_min_succ, take_take n m l]
theorem take_set_of_lt (a : α) {n m : Nat} (l : List α) (h : m < n) :
(l.set n a).take m = l.take m :=
List.ext_getElem? fun i => by
rw [getElem?_take_eq_if, getElem?_take_eq_if]
split
· next h' => rw [getElem?_set_ne (by omega)]
· rfl
@[simp] theorem take_replicate (a : α) : n m : Nat, take n (replicate m a) = replicate (min n m) a
| n, 0 => by simp [Nat.min_zero]
| 0, m => by simp [Nat.zero_min]
| succ n, succ m => by simp [replicate_succ, succ_min_succ, take_replicate]
@[simp] theorem drop_replicate (a : α) : n m : Nat, drop n (replicate m a) = replicate (m - n) a
| n, 0 => by simp
| 0, m => by simp
| succ n, succ m => by simp [replicate_succ, succ_sub_succ, drop_replicate]
/-- Taking the first `n` elements in `l₁ ++ l₂` is the same as appending the first `n` elements
of `l₁` to the first `n - l₁.length` elements of `l₂`. -/
theorem take_append_eq_append_take {l₁ l₂ : List α} {n : Nat} :
take n (l₁ ++ l₂) = take n l₁ ++ take (n - l₁.length) l₂ := by
induction l₁ generalizing n
· simp
· cases n
· simp [*]
· simp only [cons_append, take_succ_cons, length_cons, succ_eq_add_one, cons.injEq,
append_cancel_left_eq, true_and, *]
congr 1
omega
theorem take_append_of_le_length {l₁ l₂ : List α} {n : Nat} (h : n l₁.length) :
(l₁ ++ l₂).take n = l₁.take n := by
simp [take_append_eq_append_take, Nat.sub_eq_zero_of_le h]
/-- Taking the first `l₁.length + i` elements in `l₁ ++ l₂` is the same as appending the first
`i` elements of `l₂` to `l₁`. -/
theorem take_append {l₁ l₂ : List α} (i : Nat) :
take (l₁.length + i) (l₁ ++ l₂) = l₁ ++ take i l₂ := by
rw [take_append_eq_append_take, take_of_length_le (Nat.le_add_right _ _), Nat.add_sub_cancel_left]
@[simp]
theorem take_eq_take :
{l : List α} {m n : Nat}, l.take m = l.take n min m l.length = min n l.length
| [], m, n => by simp [Nat.min_zero]
| _ :: xs, 0, 0 => by simp
| x :: xs, m + 1, 0 => by simp [Nat.zero_min, succ_min_succ]
| x :: xs, 0, n + 1 => by simp [Nat.zero_min, succ_min_succ]
| x :: xs, m + 1, n + 1 => by simp [succ_min_succ, take_eq_take]
theorem take_add (l : List α) (m n : Nat) : l.take (m + n) = l.take m ++ (l.drop m).take n := by
suffices take (m + n) (take m l ++ drop m l) = take m l ++ take n (drop m l) by
rw [take_append_drop] at this
assumption
rw [take_append_eq_append_take, take_of_length_le, append_right_inj]
· simp only [take_eq_take, length_take, length_drop]
omega
apply Nat.le_trans (m := m)
· apply length_take_le
· apply Nat.le_add_right
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]
theorem map_eq_append_split {f : α β} {l : List α} {s₁ s₂ : List β}
(h : map f l = s₁ ++ s₂) : l₁ l₂, l = l₁ ++ l₂ map f l₁ = s₁ map f l₂ = s₂ := by
have := h
rw [ take_append_drop (length s₁) l] at this
rw [map_append] at this
refine _, _, rfl, append_inj this ?_
rw [length_map, length_take, Nat.min_eq_left]
rw [ length_map l f, h, length_append]
apply Nat.le_add_right
/-! ### drop -/
theorem lt_length_drop (L : List α) {i j : Nat} (h : i + j < L.length) : j < (L.drop i).length := by
have A : i < L.length := Nat.lt_of_le_of_lt (Nat.le.intro rfl) h
rw [(take_append_drop i L).symm] at h
simpa only [Nat.le_of_lt A, Nat.min_eq_left, Nat.add_lt_add_iff_left, length_take,
length_append] using h
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the big list to the small list. -/
theorem getElem_drop (L : List α) {i j : Nat} (h : i + j < L.length) :
L[i + j] = (L.drop i)[j]'(lt_length_drop L h) := by
have : i L.length := Nat.le_trans (Nat.le_add_right _ _) (Nat.le_of_lt h)
rw [getElem_of_eq (take_append_drop i L).symm h, getElem_append_right'] <;>
simp [Nat.min_eq_left this, Nat.add_sub_cancel_left, Nat.le_add_right]
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the big list to the small list. -/
@[deprecated getElem_drop (since := "2024-06-12")]
theorem get_drop (L : List α) {i j : Nat} (h : i + j < L.length) :
get L i + j, h = get (L.drop i) j, lt_length_drop L h := by
simp [getElem_drop]
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the small list to the big list. -/
theorem getElem_drop' (L : List α) {i : Nat} {j : Nat} {h : j < (L.drop i).length} :
(L.drop i)[j] = L[i + j]'(by
rw [Nat.add_comm]
exact Nat.add_lt_of_lt_sub (length_drop i L h)) := by
rw [getElem_drop]
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the small list to the big list. -/
@[deprecated getElem_drop' (since := "2024-06-12")]
theorem get_drop' (L : List α) {i j} :
get (L.drop i) j = get L i + j, by
rw [Nat.add_comm]
exact Nat.add_lt_of_lt_sub (length_drop i L j.2) := by
simp [getElem_drop']
@[simp]
theorem getElem?_drop (L : List α) (i j : Nat) : (L.drop i)[j]? = L[i + j]? := by
ext
simp only [getElem?_eq_some, getElem_drop', Option.mem_def]
constructor <;> intro h, ha
· exact _, ha
· refine ?_, ha
rw [length_drop]
rw [Nat.add_comm] at h
apply Nat.lt_sub_of_add_lt h
@[deprecated getElem?_drop (since := "2024-06-12")]
theorem get?_drop (L : List α) (i j : Nat) : get? (L.drop i) j = get? L (i + j) := by
simp
theorem head?_drop (l : List α) (n : Nat) :
(l.drop n).head? = l[n]? := by
rw [head?_eq_getElem?, getElem?_drop, Nat.add_zero]
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
simpa [head?_eq_head, getElem?_eq_getElem, h, w] 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]
rw [length_drop]
split
· rw [getElem?_eq_none (by omega)]
· rw [getLast?_eq_getElem?]
congr
omega
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_le] at h
apply Option.some_inj.1
simp only [ getLast?_eq_getLast, getLast?_drop, ite_eq_right_iff]
omega
theorem drop_length_cons {l : List α} (h : l []) (a : α) :
(a :: l).drop l.length = [l.getLast h] := by
induction l generalizing a with
| nil =>
cases h rfl
| cons y l ih =>
simp only [drop, length]
by_cases h₁ : l = []
· simp [h₁]
rw [getLast_cons h₁]
exact ih h₁ y
/-- Dropping the elements up to `n` in `l₁ ++ l₂` is the same as dropping the elements up to `n`
in `l₁`, dropping the elements up to `n - l₁.length` in `l₂`, and appending them. -/
theorem drop_append_eq_append_drop {l₁ l₂ : List α} {n : Nat} :
drop n (l₁ ++ l₂) = drop n l₁ ++ drop (n - l₁.length) l₂ := by
induction l₁ generalizing n
· simp
· cases n
· simp [*]
· simp only [cons_append, drop_succ_cons, length_cons, succ_eq_add_one, append_cancel_left_eq, *]
congr 1
omega
theorem drop_append_of_le_length {l₁ l₂ : List α} {n : Nat} (h : n l₁.length) :
(l₁ ++ l₂).drop n = l₁.drop n ++ l₂ := by
simp [drop_append_eq_append_drop, Nat.sub_eq_zero_of_le h]
/-- Dropping the elements up to `l₁.length + i` in `l₁ + l₂` is the same as dropping the elements
up to `i` in `l₂`. -/
@[simp]
theorem drop_append {l₁ l₂ : List α} (i : Nat) : drop (l₁.length + i) (l₁ ++ l₂) = drop i l₂ := by
rw [drop_append_eq_append_drop, drop_eq_nil_of_le] <;>
simp [Nat.add_sub_cancel_left, Nat.le_add_right]
theorem set_eq_take_append_cons_drop {l : List α} {n : Nat} {a : α} :
l.set n a = if n < l.length then l.take n ++ a :: l.drop (n + 1) else l := by
split <;> rename_i h
· ext1 m
by_cases h' : m < n
· rw [getElem?_append (by simp [length_take]; omega), getElem?_set_ne (by omega),
getElem?_take h']
· by_cases h'' : m = n
· subst h''
rw [getElem?_set_eq _, getElem?_append_right, length_take,
Nat.min_eq_left (by omega), Nat.sub_self, getElem?_cons_zero]
rw [length_take]
exact Nat.min_le_left m l.length
· have h''' : n < m := by omega
rw [getElem?_set_ne (by omega), getElem?_append_right, length_take,
Nat.min_eq_left (by omega)]
· obtain k, rfl := Nat.exists_eq_add_of_lt h'''
have p : n + k + 1 - n = k + 1 := by omega
rw [p]
rw [getElem?_cons_succ, getElem?_drop]
congr 1
omega
· rw [length_take]
exact Nat.le_trans (Nat.min_le_left _ _) (by omega)
· rw [set_eq_of_length_le]
omega
theorem exists_of_set {n : Nat} {a' : α} {l : List α} (h : n < l.length) :
l₁ l₂, l = l₁ ++ l[n] :: l₂ l₁.length = n l.set n a' = l₁ ++ a' :: l₂ := by
refine l.take n, l.drop (n + 1), by simp, length_take_of_le (Nat.le_of_lt h), ?_
simp [set_eq_take_append_cons_drop, h]
theorem drop_set_of_lt (a : α) {n m : Nat} (l : List α)
(hnm : n < m) : drop m (l.set n a) = l.drop m :=
ext_getElem? fun k => by simpa only [getElem?_drop] using getElem?_set_ne (by omega)
theorem drop_take : (m n : Nat) (l : List α), drop n (take m l) = take (m - n) (drop n l)
| 0, _, _ => by simp
| _, 0, _ => by simp
| _, _, [] => by simp
| m+1, n+1, h :: t => by
simp [take_succ_cons, drop_succ_cons, drop_take m n t]
congr 1
omega
theorem take_reverse {α} {xs : List α} {n : Nat} (h : n xs.length) :
xs.reverse.take n = (xs.drop (xs.length - n)).reverse := by
induction xs generalizing n <;>
simp only [reverse_cons, drop, reverse_nil, Nat.zero_sub, length, take_nil]
next xs_hd xs_tl xs_ih =>
cases Nat.lt_or_eq_of_le h with
| inl h' =>
have h' := Nat.le_of_succ_le_succ h'
rw [take_append_of_le_length, xs_ih h']
rw [show xs_tl.length + 1 - n = succ (xs_tl.length - n) from _, drop]
· rwa [succ_eq_add_one, Nat.sub_add_comm]
· rwa [length_reverse]
| inr h' =>
subst h'
rw [length, Nat.sub_self, drop]
suffices xs_tl.length + 1 = (xs_tl.reverse ++ [xs_hd]).length by
rw [this, take_length, reverse_cons]
rw [length_append, length_reverse]
rfl
@[deprecated (since := "2024-06-15")] abbrev reverse_take := @take_reverse
theorem drop_reverse {α} {xs : List α} {n : Nat} (h : n xs.length) :
xs.reverse.drop n = (xs.take (xs.length - n)).reverse := by
conv =>
rhs
rw [ reverse_reverse xs]
rw [ reverse_reverse xs] at h
generalize xs.reverse = xs' at h
rw [take_reverse]
· simp only [length_reverse, reverse_reverse] at *
congr
omega
· simp only [length_reverse, sub_le]
/-! ### rotateLeft -/
@[simp] theorem rotateLeft_replicate (n) (a : α) : rotateLeft (replicate m a) n = replicate m a := by
cases n with
| zero => simp
| succ n =>
suffices 1 < m m - (n + 1) % m + min ((n + 1) % m) m = m by
simpa [rotateLeft]
intro h
rw [Nat.min_eq_left (Nat.le_of_lt (Nat.mod_lt _ (by omega)))]
have : (n + 1) % m < m := Nat.mod_lt _ (by omega)
omega
/-! ### rotateRight -/
@[simp] theorem rotateRight_replicate (n) (a : α) : rotateRight (replicate m a) n = replicate m a := by
cases n with
| zero => simp
| succ n =>
suffices 1 < m m - (m - (n + 1) % m) + min (m - (n + 1) % m) m = m by
simpa [rotateRight]
intro h
have : (n + 1) % m < m := Nat.mod_lt _ (by omega)
rw [Nat.min_eq_left (by omega)]
omega
/-! ### zipWith -/
@[simp] theorem length_zipWith (f : α β γ) (l₁ l₂) :
length (zipWith f l₁ l₂) = min (length l₁) (length l₂) := by
induction l₁ generalizing l₂ <;> cases l₂ <;>
simp_all [succ_min_succ, Nat.zero_min, Nat.min_zero]
theorem lt_length_left_of_zipWith {f : α β γ} {i : Nat} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l.length := by rw [length_zipWith] at h; omega
theorem lt_length_right_of_zipWith {f : α β γ} {i : Nat} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l'.length := by rw [length_zipWith] at h; omega
@[simp]
theorem getElem_zipWith {f : α β γ} {l : List α} {l' : List β}
{i : Nat} {h : i < (zipWith f l l').length} :
(zipWith f l l')[i] =
f (l[i]'(lt_length_left_of_zipWith h))
(l'[i]'(lt_length_right_of_zipWith h)) := by
rw [ Option.some_inj, getElem?_eq_getElem, getElem?_zipWith_eq_some]
exact
l[i]'(lt_length_left_of_zipWith h), l'[i]'(lt_length_right_of_zipWith h),
by rw [getElem?_eq_getElem], by rw [getElem?_eq_getElem]; exact rfl, rfl
theorem zipWith_eq_zipWith_take_min : (l₁ : List α) (l₂ : List β),
zipWith f l₁ l₂ = zipWith f (l₁.take (min l₁.length l₂.length)) (l₂.take (min l₁.length l₂.length))
| [], _ => by simp
| _, [] => by simp
| a :: l₁, b :: l₂ => by simp [succ_min_succ, zipWith_eq_zipWith_take_min l₁ l₂]
theorem reverse_zipWith (h : l.length = l'.length) :
(zipWith f l l').reverse = zipWith f l.reverse l'.reverse := by
induction l generalizing l' with
| nil => simp
| cons hd tl hl =>
cases l' with
| nil => simp
| cons hd' tl' =>
simp only [Nat.add_right_cancel_iff, length] at h
have : tl.reverse.length = tl'.reverse.length := by simp [h]
simp [hl h, zipWith_append _ _ _ _ _ this]
@[deprecated reverse_zipWith (since := "2024-07-28")] abbrev zipWith_distrib_reverse := @reverse_zipWith
@[simp] theorem zipWith_replicate {a : α} {b : β} {m n : Nat} :
zipWith f (replicate m a) (replicate n b) = replicate (min m n) (f a b) := by
rw [zipWith_eq_zipWith_take_min]
simp
/-! ### zip -/
@[simp] theorem length_zip (l₁ : List α) (l₂ : List β) :
length (zip l₁ l₂) = min (length l₁) (length l₂) := by
simp [zip]
theorem lt_length_left_of_zip {i : Nat} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l.length :=
lt_length_left_of_zipWith h
theorem lt_length_right_of_zip {i : Nat} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l'.length :=
lt_length_right_of_zipWith h
@[simp]
theorem getElem_zip {l : List α} {l' : List β} {i : Nat} {h : i < (zip l l').length} :
(zip l l')[i] =
(l[i]'(lt_length_left_of_zip h), l'[i]'(lt_length_right_of_zip h)) :=
getElem_zipWith (h := h)
theorem zip_eq_zip_take_min : (l₁ : List α) (l₂ : List β),
zip l₁ l₂ = zip (l₁.take (min l₁.length l₂.length)) (l₂.take (min l₁.length l₂.length))
| [], _ => by simp
| _, [] => by simp
| a :: l₁, b :: l₂ => by simp [succ_min_succ, zip_eq_zip_take_min l₁ l₂]
@[simp] theorem zip_replicate {a : α} {b : β} {m n : Nat} :
zip (replicate m a) (replicate n b) = replicate (min m n) (a, b) := by
rw [zip_eq_zip_take_min]
simp
end List

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@@ -0,0 +1,269 @@
/-
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.Sublist
/-!
# Lemmas about `List.Pairwise` and `List.Nodup`.
-/
namespace List
open Nat
/-! ## Pairwise and Nodup -/
/-! ### Pairwise -/
theorem Pairwise.sublist : l₁ <+ l₂ l₂.Pairwise R l₁.Pairwise R
| .slnil, h => h
| .cons _ s, .cons _ h₂ => h₂.sublist s
| .cons₂ _ s, .cons h₁ h₂ => (h₂.sublist s).cons fun _ h => h₁ _ (s.subset h)
theorem Pairwise.imp {α R S} (H : {a b}, R a b S a b) :
{l : List α}, l.Pairwise R l.Pairwise S
| _, .nil => .nil
| _, .cons h₁ h₂ => .cons (H h₁ ·) (h₂.imp H)
theorem rel_of_pairwise_cons (p : (a :: l).Pairwise R) : {a'}, a' l R a a' :=
(pairwise_cons.1 p).1 _
theorem Pairwise.of_cons (p : (a :: l).Pairwise R) : Pairwise R l :=
(pairwise_cons.1 p).2
theorem Pairwise.tail : {l : List α} (_p : Pairwise R l), Pairwise R l.tail
| [], h => h
| _ :: _, h => h.of_cons
theorem Pairwise.imp_of_mem {S : α α Prop}
(H : {a b}, a l b l R a b S a b) (p : Pairwise R l) : Pairwise S l := by
induction p with
| nil => constructor
| @cons a l r _ ih =>
constructor
· exact fun x h => H (mem_cons_self ..) (mem_cons_of_mem _ h) <| r x h
· exact ih fun m m' => H (mem_cons_of_mem _ m) (mem_cons_of_mem _ m')
theorem Pairwise.and (hR : Pairwise R l) (hS : Pairwise S l) :
l.Pairwise fun a b => R a b S a b := by
induction hR with
| nil => simp only [Pairwise.nil]
| cons R1 _ IH =>
simp only [Pairwise.nil, pairwise_cons] at hS
exact fun b bl => R1 b bl, hS.1 b bl, IH hS.2
theorem pairwise_and_iff : l.Pairwise (fun a b => R a b S a b) Pairwise R l Pairwise S l :=
fun h => h.imp fun h => h.1, h.imp fun h => h.2, fun hR, hS => hR.and hS
theorem Pairwise.imp₂ (H : a b, R a b S a b T a b)
(hR : Pairwise R l) (hS : l.Pairwise S) : l.Pairwise T :=
(hR.and hS).imp fun h₁, h₂ => H _ _ h₁ h₂
theorem Pairwise.iff_of_mem {S : α α Prop} {l : List α}
(H : {a b}, a l b l (R a b S a b)) : Pairwise R l Pairwise S l :=
Pairwise.imp_of_mem fun m m' => (H m m').1, Pairwise.imp_of_mem fun m m' => (H m m').2
theorem Pairwise.iff {S : α α Prop} (H : a b, R a b S a b) {l : List α} :
Pairwise R l Pairwise S l :=
Pairwise.iff_of_mem fun _ _ => H ..
theorem pairwise_of_forall {l : List α} (H : x y, R x y) : Pairwise R l := by
induction l <;> simp [*]
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 (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 (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
induction l with
| nil => exact forall_mem_nil _
| cons a l ih =>
rw [pairwise_cons] at h₂ h₃
simp only [mem_cons]
rintro x (rfl | hx) y (rfl | hy)
· exact h₁ _ (l.mem_cons_self _)
· exact h₂.1 _ hy
· exact h₃.1 _ hx
· exact ih (fun x hx => h₁ _ <| mem_cons_of_mem _ hx) h₂.2 h₃.2 hx hy
theorem pairwise_singleton (R) (a : α) : Pairwise R [a] := by simp
theorem pairwise_pair {a b : α} : Pairwise R [a, b] R a b := by simp
theorem pairwise_map {l : List α} :
(l.map f).Pairwise R l.Pairwise fun a b => R (f a) (f b) := by
induction l
· simp
· simp only [map, pairwise_cons, forall_mem_map, *]
theorem Pairwise.of_map {S : β β Prop} (f : α β) (H : a b : α, S (f a) (f b) R a b)
(p : Pairwise S (map f l)) : Pairwise R l :=
(pairwise_map.1 p).imp (H _ _)
theorem Pairwise.map {S : β β Prop} (f : α β) (H : a b : α, R a b S (f a) (f b))
(p : Pairwise R l) : Pairwise S (map f l) :=
pairwise_map.2 <| p.imp (H _ _)
theorem pairwise_filterMap (f : β Option α) {l : List β} :
Pairwise R (filterMap f l) Pairwise (fun a a' : β => b f a, b' f a', R b b') l := by
let _S (a a' : β) := b f a, b' f a', R b b'
simp only [Option.mem_def]
induction l with
| nil => simp only [filterMap, Pairwise.nil]
| cons a l IH => ?_
match e : f a with
| none =>
rw [filterMap_cons_none e, pairwise_cons]
simp only [e, false_implies, implies_true, true_and, IH]
| some b =>
rw [filterMap_cons_some e]
simpa [IH, e] using fun _ =>
fun h a ha b hab => h _ _ ha hab, fun h a b ha hab => h _ ha _ hab
theorem Pairwise.filterMap {S : β β Prop} (f : α Option β)
(H : a a' : α, R a a' b f a, b' f a', S b b') {l : List α} (p : Pairwise R l) :
Pairwise S (filterMap f l) :=
(pairwise_filterMap _).2 <| p.imp (H _ _)
@[deprecated Pairwise.filterMap (since := "2024-07-29")] abbrev Pairwise.filter_map := @Pairwise.filterMap
theorem pairwise_filter (p : α Prop) [DecidablePred p] {l : List α} :
Pairwise R (filter p l) Pairwise (fun x y => p x p y R x y) l := by
rw [ filterMap_eq_filter, pairwise_filterMap]
simp
theorem Pairwise.filter (p : α Bool) : Pairwise R l Pairwise R (filter p l) :=
Pairwise.sublist (filter_sublist _)
theorem pairwise_append {l₁ l₂ : List α} :
(l₁ ++ l₂).Pairwise R l₁.Pairwise R l₂.Pairwise R a l₁, b l₂, R a b := by
induction l₁ <;> simp [*, or_imp, forall_and, and_assoc, and_left_comm]
theorem pairwise_append_comm {R : α α Prop} (s : {x y}, R x y R y x) {l₁ l₂ : List α} :
Pairwise R (l₁ ++ l₂) Pairwise R (l₂ ++ l₁) := by
have (l₁ l₂ : List α) (H : x : α, x l₁ y : α, y l₂ R x y)
(x : α) (xm : x l₂) (y : α) (ym : y l₁) : R x y := s (H y ym x xm)
simp only [pairwise_append, and_left_comm]; rw [Iff.intro (this l₁ l₂) (this l₂ l₁)]
theorem pairwise_middle {R : α α Prop} (s : {x y}, R x y R y x) {a : α} {l₁ l₂ : List α} :
Pairwise R (l₁ ++ a :: l₂) Pairwise R (a :: (l₁ ++ l₂)) := by
show Pairwise R (l₁ ++ ([a] ++ l₂)) Pairwise R ([a] ++ l₁ ++ l₂)
rw [ append_assoc, pairwise_append, @pairwise_append _ _ ([a] ++ l₁), pairwise_append_comm s]
simp only [mem_append, or_comm]
theorem pairwise_join {L : List (List α)} :
Pairwise R (join L)
( l L, Pairwise R l) Pairwise (fun l₁ l₂ => x l₁, y l₂, R x y) L := by
induction L with
| nil => simp
| cons l L IH =>
simp only [join, pairwise_append, IH, mem_join, exists_imp, and_imp, forall_mem_cons,
pairwise_cons, and_assoc, and_congr_right_iff]
rw [and_comm, and_congr_left_iff]
intros; exact fun h a b c d e => h c d e a b, fun h c d e a b => h a b c d e
theorem pairwise_bind {R : β β Prop} {l : List α} {f : α List β} :
List.Pairwise R (l.bind f)
( a l, Pairwise R (f a)) Pairwise (fun a₁ a₂ => x f a₁, y f a₂, R x y) l := by
simp [List.bind, pairwise_join, pairwise_map]
theorem pairwise_reverse {l : List α} :
l.reverse.Pairwise R l.Pairwise (fun a b => R b a) := by
induction l <;> simp [*, pairwise_append, and_comm]
@[simp] theorem pairwise_replicate {n : Nat} {a : α} :
(replicate n a).Pairwise R n 1 R a a := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate_succ, pairwise_cons, mem_replicate, ne_eq, and_imp,
forall_eq_apply_imp_iff, ih]
constructor
· rintro h, h' | h'
· by_cases w : n = 0
· left
subst w
simp
· right
exact h w
· right
exact h'
· rintro (h | h)
· obtain rfl := eq_zero_of_le_zero (le_of_lt_succ h)
simp
· exact fun _ => h, Or.inr h
theorem Pairwise.drop {l : List α} {n : Nat} (h : List.Pairwise R l) : List.Pairwise R (l.drop n) :=
h.sublist (drop_sublist _ _)
theorem Pairwise.take {l : List α} {n : Nat} (h : List.Pairwise R l) : List.Pairwise R (l.take n) :=
h.sublist (take_sublist _ _)
theorem pairwise_iff_forall_sublist : l.Pairwise R ( {a b}, [a,b] <+ l R a b) := by
induction l with
| nil => simp
| cons hd tl IH =>
rw [List.pairwise_cons]
constructor <;> intro h
· intro
| a, b, .cons _ hab => exact IH.mp h.2 hab
| _, b, .cons₂ _ hab => refine h.1 _ (hab.subset ?_); simp
· constructor
· intro x hx
apply h
rw [List.cons_sublist_cons, List.singleton_sublist]
exact hx
· apply IH.mpr
intro a b hab
apply h; exact hab.cons _
/-! ### Nodup -/
@[simp]
theorem nodup_nil : @Nodup α [] :=
Pairwise.nil
@[simp]
theorem nodup_cons {a : α} {l : List α} : Nodup (a :: l) a l Nodup l := by
simp only [Nodup, pairwise_cons, forall_mem_ne]
theorem Nodup.sublist : l₁ <+ l₂ Nodup l₂ Nodup l₁ :=
Pairwise.sublist
theorem Sublist.nodup : l₁ <+ l₂ Nodup l₂ Nodup l₁ :=
Nodup.sublist
theorem getElem?_inj {xs : List α}
(h₀ : i < xs.length) (h₁ : Nodup xs) (h₂ : xs[i]? = xs[j]?) : i = j := by
induction xs generalizing i j with
| nil => cases h₀
| cons x xs ih =>
match i, j with
| 0, 0 => rfl
| i+1, j+1 =>
cases h₁ with
| cons ha h₁ =>
simp only [getElem?_cons_succ] at h₂
exact congrArg (· + 1) (ih (Nat.lt_of_succ_lt_succ h₀) h₁ h₂)
| i+1, 0 => ?_
| 0, j+1 => ?_
all_goals
simp only [get?_eq_getElem?, getElem?_cons_zero, getElem?_cons_succ] at h₂
cases h₁; rename_i h' h
have := h x ?_ rfl; cases this
rw [mem_iff_get?]
simp only [get?_eq_getElem?]
exact _, h₂; exact _ , h₂.symm
@[simp] theorem nodup_replicate {n : Nat} {a : α} :
(replicate n a).Nodup n 1 := by simp [Nodup]
end List

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@@ -0,0 +1,754 @@
/-
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.TakeDrop
/-!
# Lemmas about `List.Subset`, `List.Sublist`, `List.IsPrefix`, `List.IsSuffix`, and `List.IsInfix`.
-/
namespace List
open Nat
/-! ### isPrefixOf -/
section isPrefixOf
variable [BEq α]
@[simp] theorem isPrefixOf_cons₂_self [LawfulBEq α] {a : α} :
isPrefixOf (a::as) (a::bs) = isPrefixOf as bs := by simp [isPrefixOf_cons₂]
@[simp] theorem isPrefixOf_length_pos_nil {L : List α} (h : 0 < L.length) : isPrefixOf L [] = false := by
cases L <;> simp_all [isPrefixOf]
@[simp] theorem isPrefixOf_replicate {a : α} :
isPrefixOf l (replicate n a) = (decide (l.length n) && l.all (· == a)) := by
induction l generalizing n with
| nil => simp
| cons h t ih =>
cases n
· simp
· simp [replicate_succ, isPrefixOf_cons₂, ih, Nat.succ_le_succ_iff, Bool.and_left_comm]
end isPrefixOf
/-! ### isSuffixOf -/
section isSuffixOf
variable [BEq α]
@[simp] theorem isSuffixOf_cons_nil : isSuffixOf (a::as) ([] : List α) = false := by
simp [isSuffixOf]
@[simp] theorem isSuffixOf_replicate {a : α} :
isSuffixOf l (replicate n a) = (decide (l.length n) && l.all (· == a)) := by
simp [isSuffixOf, all_eq]
end isSuffixOf
/-! ### Subset -/
/-! ### List subset -/
theorem subset_def {l₁ l₂ : List α} : l₁ l₂ {a : α}, a l₁ a l₂ := .rfl
@[simp] theorem nil_subset (l : List α) : [] l := nofun
@[simp] theorem Subset.refl (l : List α) : l l := fun _ i => i
theorem Subset.trans {l₁ l₂ l₃ : List α} (h₁ : l₁ l₂) (h₂ : l₂ l₃) : l₁ l₃ :=
fun _ i => h₂ (h₁ i)
instance : Trans (Membership.mem : α List α Prop) Subset Membership.mem :=
fun h₁ h₂ => h₂ h₁
instance : Trans (Subset : List α List α Prop) Subset Subset :=
Subset.trans
@[simp] theorem subset_cons_self (a : α) (l : List α) : l a :: l := fun _ => Mem.tail _
theorem subset_of_cons_subset {a : α} {l₁ l₂ : List α} : a :: l₁ l₂ l₁ l₂ :=
fun s _ i => s (mem_cons_of_mem _ i)
theorem subset_cons_of_subset (a : α) {l₁ l₂ : List α} : l₁ l₂ l₁ a :: l₂ :=
fun s _ i => .tail _ (s i)
theorem cons_subset_cons {l₁ l₂ : List α} (a : α) (s : l₁ l₂) : a :: l₁ a :: l₂ :=
fun _ => by simp only [mem_cons]; exact Or.imp_right (@s _)
@[simp] theorem cons_subset : a :: l m a m l m := by
simp only [subset_def, mem_cons, or_imp, forall_and, forall_eq]
@[simp] theorem subset_nil {l : List α} : l [] l = [] :=
fun h => match l with | [] => rfl | _::_ => (nomatch h (.head ..)), fun | rfl => Subset.refl _
theorem map_subset {l₁ l₂ : List α} (f : α β) (h : l₁ l₂) : map f l₁ map f l₂ :=
fun x => by simp only [mem_map]; exact .imp fun a => .imp_left (@h _)
theorem filter_subset {l₁ l₂ : List α} (p : α Bool) (H : l₁ l₂) : filter p l₁ filter p l₂ :=
fun x => by simp_all [mem_filter, subset_def.1 H]
theorem filterMap_subset {l₁ l₂ : List α} (f : α Option β) (H : l₁ l₂) :
filterMap f l₁ filterMap f l₂ := by
intro x
simp only [mem_filterMap]
rintro a, h, w
exact a, H h, w
@[simp] theorem subset_append_left (l₁ l₂ : List α) : l₁ l₁ ++ l₂ := fun _ => mem_append_left _
@[simp] theorem subset_append_right (l₁ l₂ : List α) : l₂ l₁ ++ l₂ := fun _ => mem_append_right _
theorem subset_append_of_subset_left (l₂ : List α) : l l₁ l l₁ ++ l₂ :=
fun s => Subset.trans s <| subset_append_left _ _
theorem subset_append_of_subset_right (l₁ : List α) : l l₂ l l₁ ++ l₂ :=
fun s => Subset.trans s <| subset_append_right _ _
@[simp] theorem append_subset {l₁ l₂ l : List α} :
l₁ ++ l₂ l l₁ l l₂ l := by simp [subset_def, or_imp, forall_and]
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 (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
| nil => simp
| cons x xs ih =>
simp only [cons_subset, mem_replicate, ne_eq, ih, mem_cons, forall_eq_or_imp,
and_congr_left_iff, and_iff_right_iff_imp]
solve_by_elim
@[simp] theorem reverse_subset {l₁ l₂ : List α} : reverse l₁ l₂ l₁ l₂ := by
simp [subset_def]
@[simp] theorem subset_reverse {l₁ l₂ : List α} : l₁ reverse l₂ l₁ l₂ := by
simp [subset_def]
/-! ### Sublist and isSublist -/
@[simp] theorem nil_sublist : l : List α, [] <+ l
| [] => .slnil
| a :: l => (nil_sublist l).cons a
@[simp] theorem Sublist.refl : l : List α, l <+ l
| [] => .slnil
| a :: l => (Sublist.refl l).cons₂ a
theorem Sublist.trans {l₁ l₂ l₃ : List α} (h₁ : l₁ <+ l₂) (h₂ : l₂ <+ l₃) : l₁ <+ l₃ := by
induction h₂ generalizing l₁ with
| slnil => exact h₁
| cons _ _ IH => exact (IH h₁).cons _
| @cons₂ l₂ _ a _ IH =>
generalize e : a :: l₂ = l₂'
match e h₁ with
| .slnil => apply nil_sublist
| .cons a' h₁' => cases e; apply (IH h₁').cons
| .cons₂ a' h₁' => cases e; apply (IH h₁').cons₂
instance : Trans (@Sublist α) Sublist Sublist := Sublist.trans
@[simp] theorem sublist_cons_self (a : α) (l : List α) : l <+ a :: l := (Sublist.refl l).cons _
theorem sublist_of_cons_sublist : a :: l₁ <+ l₂ l₁ <+ l₂ :=
(sublist_cons_self a l₁).trans
@[simp]
theorem cons_sublist_cons : a :: l₁ <+ a :: l₂ l₁ <+ l₂ :=
fun | .cons _ s => sublist_of_cons_sublist s | .cons₂ _ s => s, .cons₂ _
theorem sublist_or_mem_of_sublist (h : l <+ l₁ ++ a :: l₂) : l <+ l₁ ++ l₂ a l := by
induction l₁ generalizing l with
| nil => match h with
| .cons _ h => exact .inl h
| .cons₂ _ h => exact .inr (.head ..)
| cons b l₁ IH =>
match h with
| .cons _ h => exact (IH h).imp_left (Sublist.cons _)
| .cons₂ _ h => exact (IH h).imp (Sublist.cons₂ _) (.tail _)
theorem Sublist.subset : l₁ <+ l₂ l₁ l₂
| .slnil, _, h => h
| .cons _ s, _, h => .tail _ (s.subset h)
| .cons₂ .., _, .head .. => .head ..
| .cons₂ _ s, _, .tail _ h => .tail _ (s.subset h)
instance : Trans (@Sublist α) Subset Subset :=
fun h₁ h₂ => trans h₁.subset h₂
instance : Trans Subset (@Sublist α) Subset :=
fun h₁ h₂ => trans h₁ h₂.subset
instance : Trans (Membership.mem : α List α Prop) Sublist Membership.mem :=
fun h₁ h₂ => h₂.subset h₁
theorem mem_of_cons_sublist {a : α} {l₁ l₂ : List α} (s : a :: l₁ <+ l₂) : a l₂ :=
(cons_subset.1 s.subset).1
@[simp] theorem sublist_nil {l : List α} : l <+ [] l = [] :=
fun s => subset_nil.1 s.subset, fun H => H Sublist.refl _
theorem Sublist.length_le : l₁ <+ l₂ length l₁ length l₂
| .slnil => Nat.le_refl 0
| .cons _l s => le_succ_of_le (length_le s)
| .cons₂ _ s => succ_le_succ (length_le s)
theorem Sublist.eq_of_length : l₁ <+ l₂ length l₁ = length l₂ l₁ = l₂
| .slnil, _ => rfl
| .cons a s, h => nomatch Nat.not_lt.2 s.length_le (h lt_succ_self _)
| .cons₂ a s, h => by rw [s.eq_of_length (succ.inj h)]
theorem Sublist.eq_of_length_le (s : l₁ <+ l₂) (h : length l₂ length l₁) : l₁ = l₂ :=
s.eq_of_length <| Nat.le_antisymm s.length_le h
theorem Sublist.length_eq (s : l₁ <+ l₂) : length l₁ = length l₂ l₁ = l₂ :=
s.eq_of_length, congrArg _
protected theorem Sublist.map (f : α β) {l₁ l₂} (s : l₁ <+ l₂) : map f l₁ <+ map f l₂ := by
induction s with
| slnil => simp
| cons a s ih =>
simpa using cons (f a) ih
| cons₂ a s ih =>
simpa using cons₂ (f a) ih
protected theorem Sublist.filterMap (f : α Option β) (s : l₁ <+ l₂) :
filterMap f l₁ <+ filterMap f l₂ := by
induction s <;> simp [filterMap_cons] <;> split <;> simp [*, cons, cons₂]
protected theorem Sublist.filter (p : α Bool) {l₁ l₂} (s : l₁ <+ l₂) : filter p l₁ <+ filter p l₂ := by
rw [ filterMap_eq_filter]; apply s.filterMap
theorem sublist_filterMap_iff {l₁ : List β} {f : α Option β} :
l₁ <+ l₂.filterMap f l', l' <+ l₂ l₁ = l'.filterMap f := by
induction l₂ generalizing l₁ with
| nil => simp
| cons a l₂ ih =>
simp only [filterMap_cons]
split
· simp only [ih]
constructor
· rintro l', h, rfl
exact l', Sublist.cons a h, rfl
· rintro l', h, rfl
cases h with
| cons _ h =>
exact l', h, rfl
| cons₂ _ h =>
rename_i l'
exact l', h, by simp_all
· constructor
· intro w
cases w with
| cons _ h =>
obtain l', s, rfl := ih.1 h
exact l', Sublist.cons a s, rfl
| cons₂ _ h =>
rename_i l'
obtain l', s, rfl := ih.1 h
refine a :: l', Sublist.cons₂ a s, ?_
rwa [filterMap_cons_some]
· rintro l', h, rfl
replace h := h.filterMap f
rwa [filterMap_cons_some] at h
assumption
theorem sublist_map_iff {l₁ : List β} {f : α β} :
l₁ <+ l₂.map f l', l' <+ l₂ l₁ = l'.map f := by
simp only [ filterMap_eq_map, sublist_filterMap_iff]
theorem sublist_filter_iff {l₁ : List α} {p : α Bool} :
l₁ <+ l₂.filter p l', l' <+ l₂ l₁ = l'.filter p := by
simp only [ filterMap_eq_filter, sublist_filterMap_iff]
@[simp] theorem sublist_append_left : l₁ l₂ : List α, l₁ <+ l₁ ++ l₂
| [], _ => nil_sublist _
| _ :: l₁, l₂ => (sublist_append_left l₁ l₂).cons₂ _
@[simp] theorem sublist_append_right : l₁ l₂ : List α, l₂ <+ l₁ ++ l₂
| [], _ => Sublist.refl _
| _ :: l₁, l₂ => (sublist_append_right l₁ l₂).cons _
@[simp] theorem singleton_sublist {a : α} {l} : [a] <+ l a l := by
refine fun h => h.subset (mem_singleton_self _), fun h => ?_
obtain _, _, rfl := append_of_mem h
exact ((nil_sublist _).cons₂ _).trans (sublist_append_right ..)
theorem sublist_append_of_sublist_left (s : l <+ l₁) : l <+ l₁ ++ l₂ :=
s.trans <| sublist_append_left ..
theorem sublist_append_of_sublist_right (s : l <+ l₂) : l <+ l₁ ++ l₂ :=
s.trans <| sublist_append_right ..
@[simp] theorem append_sublist_append_left : l, l ++ l₁ <+ l ++ l₂ l₁ <+ l₂
| [] => Iff.rfl
| _ :: l => cons_sublist_cons.trans (append_sublist_append_left l)
theorem Sublist.append_left : l₁ <+ l₂ l, l ++ l₁ <+ l ++ l₂ :=
fun h l => (append_sublist_append_left l).mpr h
theorem Sublist.append_right : l₁ <+ l₂ l, l₁ ++ l <+ l₂ ++ l
| .slnil, _ => Sublist.refl _
| .cons _ h, _ => (h.append_right _).cons _
| .cons₂ _ h, _ => (h.append_right _).cons₂ _
theorem Sublist.append (hl : l₁ <+ l₂) (hr : r₁ <+ r₂) : l₁ ++ r₁ <+ l₂ ++ r₂ :=
(hl.append_right _).trans ((append_sublist_append_left _).2 hr)
theorem sublist_cons_iff {a : α} {l l'} :
l <+ a :: l' l <+ l' r, l = a :: r r <+ l' := by
constructor
· intro h
cases h with
| cons _ h => exact Or.inl h
| cons₂ _ h => exact Or.inr _, rfl, h
· rintro (h | r, rfl, h)
· exact h.cons _
· exact h.cons₂ _
theorem cons_sublist_iff {a : α} {l l'} :
a :: l <+ l' r₁ r₂, l' = r₁ ++ r₂ a r₁ l <+ r₂ := by
induction l' with
| nil => simp
| cons a' l' ih =>
constructor
· intro w
cases w with
| cons _ w =>
obtain r₁, r₂, rfl, h₁, h₂ := ih.1 w
exact a' :: r₁, r₂, by simp, mem_cons_of_mem a' h₁, h₂
| cons₂ _ w =>
exact [a], l', by simp, mem_singleton_self _, w
· rintro r₁, r₂, w, h₁, h₂
rw [w, singleton_append]
exact Sublist.append (by simpa) h₂
theorem sublist_append_iff {l : List α} :
l <+ r₁ ++ r₂ l₁ l₂, l = l₁ ++ l₂ l₁ <+ r₁ l₂ <+ r₂ := by
induction r₁ generalizing l with
| nil =>
constructor
· intro w
refine [], l, by simp_all
· rintro l₁, l₂, rfl, w₁, w₂
simp_all
| cons r r₁ ih =>
constructor
· intro w
simp only [cons_append] at w
cases w with
| cons _ w =>
obtain l₁, l₂, rfl, w₁, w₂ := ih.1 w
exact l₁, l₂, rfl, Sublist.cons r w₁, w₂
| cons₂ _ w =>
rename_i l
obtain l₁, l₂, rfl, w₁, w₂ := ih.1 w
refine r :: l₁, l₂, by simp, cons_sublist_cons.mpr w₁, w₂
· rintro l₁, l₂, rfl, w₁, w₂
cases w₁ with
| cons _ w₁ =>
exact Sublist.cons _ (Sublist.append w₁ w₂)
| cons₂ _ w₁ =>
rename_i l
exact Sublist.cons₂ _ (Sublist.append w₁ w₂)
theorem append_sublist_iff {l₁ l₂ : List α} :
l₁ ++ l₂ <+ r r₁ r₂, r = r₁ ++ r₂ l₁ <+ r₁ l₂ <+ r₂ := by
induction l₁ generalizing r with
| nil =>
constructor
· intro w
refine [], r, by simp_all
· rintro r₁, r₂, rfl, -, w₂
simp only [nil_append]
exact sublist_append_of_sublist_right w₂
| cons a l₁ ih =>
constructor
· rw [cons_append, cons_sublist_iff]
rintro r₁, r₂, rfl, h₁, h₂
obtain s₁, s₂, rfl, t₁, t₂ := ih.1 h₂
refine r₁ ++ s₁, s₂, by simp, ?_, t₂
rw [ singleton_append]
exact Sublist.append (by simpa) t₁
· rintro r₁, r₂, rfl, h₁, h₂
exact Sublist.append h₁ h₂
theorem Sublist.reverse : l₁ <+ l₂ l₁.reverse <+ l₂.reverse
| .slnil => Sublist.refl _
| .cons _ h => by rw [reverse_cons]; exact sublist_append_of_sublist_left h.reverse
| .cons₂ _ h => by rw [reverse_cons, reverse_cons]; exact h.reverse.append_right _
@[simp] theorem reverse_sublist : l₁.reverse <+ l₂.reverse l₁ <+ l₂ :=
fun h => l₁.reverse_reverse l₂.reverse_reverse h.reverse, Sublist.reverse
theorem sublist_reverse_iff : l₁ <+ l₂.reverse l₁.reverse <+ l₂ :=
by rw [ reverse_sublist, reverse_reverse]
@[simp] theorem append_sublist_append_right (l) : l₁ ++ l <+ l₂ ++ l l₁ <+ l₂ :=
fun h => by
have := h.reverse
simp only [reverse_append, append_sublist_append_left, reverse_sublist] at this
exact this,
fun h => h.append_right l
@[simp] theorem replicate_sublist_replicate {m n} (a : α) :
replicate m a <+ replicate n a m n := by
refine fun h => ?_, fun h => ?_
· have := h.length_le; simp only [length_replicate] at this ; exact this
· induction h with
| refl => apply Sublist.refl
| step => simp [*, replicate, Sublist.cons]
theorem sublist_replicate_iff : l <+ replicate m a n, n m l = replicate n a := by
induction l generalizing m with
| nil =>
simp only [nil_sublist, true_iff]
exact 0, zero_le m, by simp
| cons b l ih =>
constructor
· intro w
cases m with
| zero => simp at w
| succ m =>
simp [replicate_succ] at w
cases w with
| cons _ w =>
obtain n, le, rfl := ih.1 (sublist_of_cons_sublist w)
obtain rfl := (mem_replicate.1 (mem_of_cons_sublist w)).2
exact n+1, Nat.add_le_add_right le 1, rfl
| cons₂ _ w =>
obtain n, le, rfl := ih.1 w
refine n+1, Nat.add_le_add_right le 1, by simp [replicate_succ]
· rintro n, le, w
rw [w]
exact (replicate_sublist_replicate a).2 le
theorem sublist_join_of_mem {L : List (List α)} {l} (h : l L) : l <+ L.join := by
induction L with
| nil => cases h
| cons l' L ih =>
rcases mem_cons.1 h with (rfl | h)
· simp [h]
· simp [ih h, join_cons, sublist_append_of_sublist_right]
theorem sublist_join_iff {L : List (List α)} {l} :
l <+ L.join
L' : List (List α), l = L'.join i (_ : i < L'.length), L'[i] <+ L[i]?.getD [] := by
induction L generalizing l with
| nil =>
constructor
· intro w
simp only [join_nil, sublist_nil] at w
subst w
exact [], by simp, fun i x => by cases x
· rintro L', rfl, h
simp only [join_nil, sublist_nil, join_eq_nil_iff]
simp only [getElem?_nil, Option.getD_none, sublist_nil] at h
exact (forall_getElem L' (· = [])).1 h
| cons l' L ih =>
simp only [join_cons, sublist_append_iff, ih]
constructor
· rintro l₁, l₂, rfl, s, L', rfl, h
refine l₁ :: L', by simp, ?_
intro i lt
cases i <;> simp_all
· rintro L', rfl, h
cases L' with
| nil =>
exact [], [], by simp, by simp, [], by simp, fun i x => by cases x
| cons l₁ L' =>
exact l₁, L'.join, by simp, by simpa using h 0 (by simp), L', rfl,
fun i lt => by simpa using h (i+1) (Nat.add_lt_add_right lt 1)
theorem join_sublist_iff {L : List (List α)} {l} :
L.join <+ l
L' : List (List α), l = L'.join i (_ : i < L.length), L[i] <+ L'[i]?.getD [] := by
induction L generalizing l with
| nil =>
constructor
· intro _
exact [l], by simp, fun i x => by cases x
· rintro L', rfl, _
simp only [join_nil, nil_sublist]
| cons l' L ih =>
simp only [join_cons, append_sublist_iff, ih]
constructor
· rintro l₁, l₂, rfl, s, L', rfl, h
refine l₁ :: L', by simp, ?_
intro i lt
cases i <;> simp_all
· rintro L', rfl, h
cases L' with
| nil =>
exact [], [], by simp, by simpa using h 0 (by simp), [], by simp,
fun i x => by simpa using h (i+1) (Nat.add_lt_add_right x 1)
| cons l₁ L' =>
exact l₁, L'.join, by simp, by simpa using h 0 (by simp), L', rfl,
fun i lt => by simpa using h (i+1) (Nat.add_lt_add_right lt 1)
@[simp] theorem isSublist_iff_sublist [BEq α] [LawfulBEq α] {l₁ l₂ : List α} :
l₁.isSublist l₂ l₁ <+ l₂ := by
cases l₁ <;> cases l₂ <;> simp [isSublist]
case cons.cons hd₁ tl₁ hd₂ tl₂ =>
if h_eq : hd₁ = hd₂ then
simp [h_eq, cons_sublist_cons, isSublist_iff_sublist]
else
simp only [beq_iff_eq, h_eq]
constructor
· intro h_sub
apply Sublist.cons
exact isSublist_iff_sublist.mp h_sub
· intro h_sub
cases h_sub
case cons h_sub =>
exact isSublist_iff_sublist.mpr h_sub
case cons₂ =>
contradiction
instance [DecidableEq α] (l₁ l₂ : List α) : Decidable (l₁ <+ l₂) :=
decidable_of_iff (l₁.isSublist l₂) isSublist_iff_sublist
/-! ### IsPrefix / IsSuffix / IsInfix -/
@[simp] theorem prefix_append (l₁ l₂ : List α) : l₁ <+: l₁ ++ l₂ := l₂, rfl
@[simp] theorem suffix_append (l₁ l₂ : List α) : l₂ <:+ l₁ ++ l₂ := l₁, rfl
theorem infix_append (l₁ l₂ l₃ : List α) : l₂ <:+: l₁ ++ l₂ ++ l₃ := l₁, l₃, rfl
@[simp] theorem infix_append' (l₁ l₂ l₃ : List α) : l₂ <:+: l₁ ++ (l₂ ++ l₃) := by
rw [ List.append_assoc]; apply infix_append
theorem IsPrefix.isInfix : l₁ <+: l₂ l₁ <:+: l₂ := fun t, h => [], t, h
theorem IsSuffix.isInfix : l₁ <:+ l₂ l₁ <:+: l₂ := fun t, h => t, [], by rw [h, append_nil]
@[simp] theorem nil_prefix (l : List α) : [] <+: l := l, rfl
@[simp] theorem nil_suffix (l : List α) : [] <:+ l := l, append_nil _
@[simp] theorem nil_infix (l : List α) : [] <:+: l := (nil_prefix _).isInfix
@[simp] theorem prefix_refl (l : List α) : l <+: l := [], append_nil _
@[simp] theorem suffix_refl (l : List α) : l <:+ l := [], rfl
@[simp] theorem infix_refl (l : List α) : l <:+: l := (prefix_refl l).isInfix
@[simp] theorem suffix_cons (a : α) : l, l <:+ a :: l := suffix_append [a]
theorem infix_cons : l₁ <:+: l₂ l₁ <:+: a :: l₂ := fun L₁, L₂, h => a :: L₁, L₂, h rfl
theorem infix_concat : l₁ <:+: l₂ l₁ <:+: concat l₂ a := fun L₁, L₂, h =>
L₁, concat L₂ a, by simp [ h, concat_eq_append, append_assoc]
theorem IsPrefix.trans : {l₁ l₂ l₃ : List α}, l₁ <+: l₂ l₂ <+: l₃ l₁ <+: l₃
| _, _, _, r₁, rfl, r₂, rfl => r₁ ++ r₂, (append_assoc _ _ _).symm
theorem IsSuffix.trans : {l₁ l₂ l₃ : List α}, l₁ <:+ l₂ l₂ <:+ l₃ l₁ <:+ l₃
| _, _, _, l₁, rfl, l₂, rfl => l₂ ++ l₁, append_assoc _ _ _
theorem IsInfix.trans : {l₁ l₂ l₃ : List α}, l₁ <:+: l₂ l₂ <:+: l₃ l₁ <:+: l₃
| l, _, _, l₁, r₁, rfl, l₂, r₂, rfl => l₂ ++ l₁, r₁ ++ r₂, by simp only [append_assoc]
protected theorem IsInfix.sublist : l₁ <:+: l₂ l₁ <+ l₂
| _, _, h => h (sublist_append_right ..).trans (sublist_append_left ..)
protected theorem IsInfix.subset (hl : l₁ <:+: l₂) : l₁ l₂ :=
hl.sublist.subset
protected theorem IsPrefix.sublist (h : l₁ <+: l₂) : l₁ <+ l₂ :=
h.isInfix.sublist
protected theorem IsPrefix.subset (hl : l₁ <+: l₂) : l₁ l₂ :=
hl.sublist.subset
protected theorem IsSuffix.sublist (h : l₁ <:+ l₂) : l₁ <+ l₂ :=
h.isInfix.sublist
protected theorem IsSuffix.subset (hl : l₁ <:+ l₂) : l₁ l₂ :=
hl.sublist.subset
@[simp] theorem reverse_suffix : reverse l₁ <:+ reverse l₂ l₁ <+: l₂ :=
fun r, e => reverse r, by rw [ reverse_reverse l₁, reverse_append, e, reverse_reverse],
fun r, e => reverse r, by rw [ reverse_append, e]
@[simp] theorem reverse_prefix : reverse l₁ <+: reverse l₂ l₁ <:+ l₂ := by
rw [ reverse_suffix]; simp only [reverse_reverse]
@[simp] theorem reverse_infix : reverse l₁ <:+: reverse l₂ l₁ <:+: l₂ := by
refine fun s, t, e => reverse t, reverse s, ?_, fun s, t, e => reverse t, reverse s, ?_
· rw [ reverse_reverse l₁, append_assoc, reverse_append, reverse_append, e,
reverse_reverse]
· rw [append_assoc, reverse_append, reverse_append, e]
theorem IsInfix.length_le (h : l₁ <:+: l₂) : l₁.length l₂.length :=
h.sublist.length_le
theorem IsPrefix.length_le (h : l₁ <+: l₂) : l₁.length l₂.length :=
h.sublist.length_le
theorem IsSuffix.length_le (h : l₁ <:+ l₂) : l₁.length l₂.length :=
h.sublist.length_le
@[simp] theorem infix_nil : l <:+: [] l = [] := (sublist_nil.1 ·.sublist), (· infix_refl _)
@[simp] theorem prefix_nil : l <+: [] l = [] := (sublist_nil.1 ·.sublist), (· prefix_refl _)
@[simp] theorem suffix_nil : l <:+ [] l = [] := (sublist_nil.1 ·.sublist), (· suffix_refl _)
theorem infix_iff_prefix_suffix (l₁ l₂ : List α) : l₁ <:+: l₂ t, l₁ <+: t t <:+ l₂ :=
fun _, t, e => l₁ ++ t, _, rfl, e append_assoc .. _, rfl,
fun _, t, rfl, s, e => s, t, append_assoc .. e
theorem IsInfix.eq_of_length (h : l₁ <:+: l₂) : l₁.length = l₂.length l₁ = l₂ :=
h.sublist.eq_of_length
theorem IsPrefix.eq_of_length (h : l₁ <+: l₂) : l₁.length = l₂.length l₁ = l₂ :=
h.sublist.eq_of_length
theorem IsSuffix.eq_of_length (h : l₁ <:+ l₂) : l₁.length = l₂.length l₁ = l₂ :=
h.sublist.eq_of_length
theorem prefix_of_prefix_length_le :
{l₁ l₂ l₃ : List α}, l₁ <+: l₃ l₂ <+: l₃ length l₁ length l₂ l₁ <+: l₂
| [], l₂, _, _, _, _ => nil_prefix _
| a :: l₁, b :: l₂, _, r₁, rfl, r₂, e, ll => by
injection e with _ e'; subst b
rcases prefix_of_prefix_length_le _, rfl _, e' (le_of_succ_le_succ ll) with r₃, rfl
exact r₃, rfl
theorem prefix_or_prefix_of_prefix (h₁ : l₁ <+: l₃) (h₂ : l₂ <+: l₃) : l₁ <+: l₂ l₂ <+: l₁ :=
(Nat.le_total (length l₁) (length l₂)).imp (prefix_of_prefix_length_le h₁ h₂)
(prefix_of_prefix_length_le h₂ h₁)
theorem suffix_of_suffix_length_le
(h₁ : l₁ <:+ l₃) (h₂ : l₂ <:+ l₃) (ll : length l₁ length l₂) : l₁ <:+ l₂ :=
reverse_prefix.1 <|
prefix_of_prefix_length_le (reverse_prefix.2 h₁) (reverse_prefix.2 h₂) (by simp [ll])
theorem suffix_or_suffix_of_suffix (h₁ : l₁ <:+ l₃) (h₂ : l₂ <:+ l₃) : l₁ <:+ l₂ l₂ <:+ l₁ :=
(prefix_or_prefix_of_prefix (reverse_prefix.2 h₁) (reverse_prefix.2 h₂)).imp reverse_prefix.1
reverse_prefix.1
theorem prefix_cons_iff : l₁ <+: a :: l₂ l₁ = [] t, l₁ = a :: t t <+: l₂ := by
cases l₁ with
| nil => simp
| cons a' l₁ =>
constructor
· rintro t, h
simp at h
obtain rfl, rfl := h
exact Or.inr l₁, rfl, prefix_append l₁ t
· rintro (h | t, w, s, h')
· simp [h]
· simp only [w]
refine s, by simp [h']
@[simp] theorem cons_prefix_cons : a :: l₁ <+: b :: l₂ a = b l₁ <+: l₂ := by
simp only [prefix_cons_iff, cons.injEq, false_or]
constructor
· rintro t, rfl, rfl, h
exact rfl, h
· rintro rfl, h
exact l₁, rfl, rfl, h
theorem suffix_cons_iff : l₁ <:+ a :: l₂ l₁ = a :: l₂ l₁ <:+ l₂ := by
constructor
· rintro hd, tl, hl₃
· exact Or.inl hl₃
· simp only [cons_append] at hl₃
injection hl₃ with _ hl₄
exact Or.inr _, hl₄
· rintro (rfl | hl₁)
· exact (a :: l₂).suffix_refl
· exact hl₁.trans (l₂.suffix_cons _)
theorem infix_cons_iff : l₁ <:+: a :: l₂ l₁ <+: a :: l₂ l₁ <:+: l₂ := by
constructor
· rintro hd, tl, t, hl₃
· exact Or.inl t, hl₃
· simp only [cons_append] at hl₃
injection hl₃ with _ hl₄
exact Or.inr _, t, hl₄
· rintro (h | hl₁)
· exact h.isInfix
· exact infix_cons hl₁
theorem infix_of_mem_join : {L : List (List α)}, l L l <:+: join L
| l' :: _, h =>
match h with
| List.Mem.head .. => infix_append [] _ _
| List.Mem.tail _ hlMemL =>
IsInfix.trans (infix_of_mem_join hlMemL) <| (suffix_append _ _).isInfix
theorem prefix_append_right_inj (l) : l ++ l₁ <+: l ++ l₂ l₁ <+: l₂ :=
exists_congr fun r => by rw [append_assoc, append_right_inj]
@[simp]
theorem prefix_cons_inj (a) : a :: l₁ <+: a :: l₂ l₁ <+: l₂ :=
prefix_append_right_inj [a]
theorem take_prefix (n) (l : List α) : take n l <+: l :=
_, take_append_drop _ _
theorem drop_suffix (n) (l : List α) : drop n l <:+ l :=
_, take_append_drop _ _
theorem take_sublist (n) (l : List α) : take n l <+ l :=
(take_prefix n l).sublist
theorem drop_sublist (n) (l : List α) : drop n l <+ l :=
(drop_suffix n l).sublist
theorem take_subset (n) (l : List α) : take n l l :=
(take_sublist n l).subset
theorem drop_subset (n) (l : List α) : drop n l l :=
(drop_sublist n l).subset
theorem mem_of_mem_take {l : List α} (h : a l.take n) : a l :=
take_subset n l h
theorem mem_of_mem_drop {n} {l : List α} (h : a l.drop n) : a l :=
drop_subset _ _ h
theorem IsPrefix.filter (p : α Bool) l₁ l₂ : List α (h : l₁ <+: l₂) :
l₁.filter p <+: l₂.filter p := by
obtain xs, rfl := h
rw [filter_append]; apply prefix_append
theorem IsSuffix.filter (p : α Bool) l₁ l₂ : List α (h : l₁ <:+ l₂) :
l₁.filter p <:+ l₂.filter p := by
obtain xs, rfl := h
rw [filter_append]; apply suffix_append
theorem IsInfix.filter (p : α Bool) l₁ l₂ : List α (h : l₁ <:+: l₂) :
l₁.filter p <:+: l₂.filter p := by
obtain xs, ys, rfl := h
rw [filter_append, filter_append]; apply infix_append _
@[simp] theorem isPrefixOf_iff_prefix [BEq α] [LawfulBEq α] {l₁ l₂ : List α} :
l₁.isPrefixOf l₂ l₁ <+: l₂ := by
induction l₁ generalizing l₂ with
| nil => simp
| cons a l₁ ih =>
cases l₂ with
| nil => simp
| cons a' l₂ => simp [isPrefixOf, ih]
instance [DecidableEq α] (l₁ l₂ : List α) : Decidable (l₁ <+: l₂) :=
decidable_of_iff (l₁.isPrefixOf l₂) isPrefixOf_iff_prefix
@[simp] theorem isSuffixOf_iff_suffix [BEq α] [LawfulBEq α] {l₁ l₂ : List α} :
l₁.isSuffixOf l₂ l₁ <:+ l₂ := by
simp [isSuffixOf]
instance [DecidableEq α] (l₁ l₂ : List α) : Decidable (l₁ <:+ l₂) :=
decidable_of_iff (l₁.isSuffixOf l₂) isSuffixOf_iff_suffix
end List

View File

@@ -5,499 +5,443 @@ Authors: Parikshit Khanna, Jeremy Avigad, Leonardo de Moura, Floris van Doorn, M
-/
prelude
import Init.Data.List.Lemmas
import Init.Data.Nat.Lemmas
/-!
# Further lemmas about `List.take`, `List.drop`, `List.zip` and `List.zipWith`.
These are in a separate file from most of the list lemmas
as they required importing more lemmas about natural numbers, and use `omega`.
# Lemmas about `List.zip`, `List.zipWith`, `List.zipWithAll`, and `List.unzip`.
-/
namespace List
open Nat
/-! ### take -/
/-! ### take and drop
@[simp] theorem length_take : (i : Nat) (l : List α), length (take i l) = min i (length l)
| 0, l => by simp [Nat.zero_min]
| succ n, [] => by simp [Nat.min_zero]
| succ n, _ :: l => by simp [Nat.succ_min_succ, length_take]
theorem length_take_le (n) (l : List α) : length (take n l) n := by simp [Nat.min_le_left]
theorem length_take_le' (n) (l : List α) : length (take n l) l.length :=
by simp [Nat.min_le_right]
theorem length_take_of_le (h : n length l) : length (take n l) = n := by simp [Nat.min_eq_left h]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the big list to the small list. -/
theorem getElem_take (L : List α) {i j : Nat} (hi : i < L.length) (hj : i < j) :
L[i] = (L.take j)[i]'(length_take .. Nat.lt_min.mpr hj, hi) :=
getElem_of_eq (take_append_drop j L).symm _ getElem_append ..
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the small list to the big list. -/
theorem getElem_take' (L : List α) {j i : Nat} {h : i < (L.take j).length} :
(L.take j)[i] =
L[i]'(Nat.lt_of_lt_of_le h (length_take_le' _ _)) := by
rw [length_take, Nat.lt_min] at h; rw [getElem_take L _ h.1]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the big list to the small list. -/
@[deprecated getElem_take (since := "2024-06-12")]
theorem get_take (L : List α) {i j : Nat} (hi : i < L.length) (hj : i < j) :
get L i, hi = get (L.take j) i, length_take .. Nat.lt_min.mpr hj, hi := by
simp [getElem_take _ hi hj]
/-- The `i`-th element of a list coincides with the `i`-th element of any of its prefixes of
length `> i`. Version designed to rewrite from the small list to the big list. -/
@[deprecated getElem_take (since := "2024-06-12")]
theorem get_take' (L : List α) {j i} :
get (L.take j) i =
get L i.1, Nat.lt_of_lt_of_le i.2 (length_take_le' _ _) := by
simp [getElem_take']
theorem getElem?_take_eq_none {l : List α} {n m : Nat} (h : n m) :
(l.take n)[m]? = none :=
getElem?_eq_none <| Nat.le_trans (length_take_le _ _) h
@[deprecated getElem?_take_eq_none (since := "2024-06-12")]
theorem get?_take_eq_none {l : List α} {n m : Nat} (h : n m) :
(l.take n).get? m = none := by
simp [getElem?_take_eq_none h]
theorem getElem?_take_eq_if {l : List α} {n m : Nat} :
(l.take n)[m]? = if m < n then l[m]? else none := by
split
· next h => exact getElem?_take h
· next h => exact getElem?_take_eq_none (Nat.le_of_not_lt h)
@[deprecated getElem?_take_eq_if (since := "2024-06-12")]
theorem get?_take_eq_if {l : List α} {n m : Nat} :
(l.take n).get? m = if m < n then l.get? m else none := by
simp [getElem?_take_eq_if]
theorem head?_take {l : List α} {n : Nat} :
(l.take n).head? = if n = 0 then none else l.head? := by
simp [head?_eq_getElem?, getElem?_take_eq_if]
split
· rw [if_neg (by omega)]
· rw [if_pos (by omega)]
theorem head_take {l : List α} {n : Nat} (h : l.take n []) :
(l.take n).head h = l.head (by simp_all) := by
apply Option.some_inj.1
rw [ head?_eq_head, head?_eq_head, head?_take, if_neg]
simp_all
theorem getLast?_take {l : List α} : (l.take n).getLast? = if n = 0 then none else l[n - 1]?.or l.getLast? := by
rw [getLast?_eq_getElem?, getElem?_take_eq_if, length_take]
split
· rw [if_neg (by omega)]
rw [Nat.min_def]
split
· rw [getElem?_eq_getElem (by omega)]
simp
· rw [ getLast?_eq_getElem?, getElem?_eq_none (by omega)]
simp
· rw [if_pos]
omega
theorem getLast_take {l : List α} (h : l.take n []) :
(l.take n).getLast h = l[n - 1]?.getD (l.getLast (by simp_all)) := by
rw [getLast_eq_getElem, getElem_take']
simp [length_take, Nat.min_def]
simp at h
split
· rw [getElem?_eq_getElem (by omega)]
simp
· rw [getElem?_eq_none (by omega), getLast_eq_getElem]
simp
theorem take_take : (n m) (l : List α), take n (take m l) = take (min n m) l
| n, 0, l => by rw [Nat.min_zero, take_zero, take_nil]
| 0, m, l => by rw [Nat.zero_min, take_zero, take_zero]
| succ n, succ m, nil => by simp only [take_nil]
| succ n, succ m, a :: l => by
simp only [take, succ_min_succ, take_take n m l]
theorem take_set_of_lt (a : α) {n m : Nat} (l : List α) (h : m < n) :
(l.set n a).take m = l.take m :=
List.ext_getElem? fun i => by
rw [getElem?_take_eq_if, getElem?_take_eq_if]
split
· next h' => rw [getElem?_set_ne (by omega)]
· rfl
@[simp] theorem take_replicate (a : α) : n m : Nat, take n (replicate m a) = replicate (min n m) a
| n, 0 => by simp [Nat.min_zero]
| 0, m => by simp [Nat.zero_min]
| succ n, succ m => by simp [replicate_succ, succ_min_succ, take_replicate]
@[simp] theorem drop_replicate (a : α) : n m : Nat, drop n (replicate m a) = replicate (m - n) a
| n, 0 => by simp
| 0, m => by simp
| succ n, succ m => by simp [replicate_succ, succ_sub_succ, drop_replicate]
/-- Taking the first `n` elements in `l₁ ++ l₂` is the same as appending the first `n` elements
of `l₁` to the first `n - l₁.length` elements of `l₂`. -/
theorem take_append_eq_append_take {l₁ l₂ : List α} {n : Nat} :
take n (l₁ ++ l₂) = take n l₁ ++ take (n - l₁.length) l₂ := by
induction l₁ generalizing n
· simp
· cases n
· simp [*]
· simp only [cons_append, take_succ_cons, length_cons, succ_eq_add_one, cons.injEq,
append_cancel_left_eq, true_and, *]
congr 1
omega
theorem take_append_of_le_length {l₁ l₂ : List α} {n : Nat} (h : n l₁.length) :
(l₁ ++ l₂).take n = l₁.take n := by
simp [take_append_eq_append_take, Nat.sub_eq_zero_of_le h]
/-- Taking the first `l₁.length + i` elements in `l₁ ++ l₂` is the same as appending the first
`i` elements of `l₂` to `l₁`. -/
theorem take_append {l₁ l₂ : List α} (i : Nat) :
take (l₁.length + i) (l₁ ++ l₂) = l₁ ++ take i l₂ := by
rw [take_append_eq_append_take, take_of_length_le (Nat.le_add_right _ _), Nat.add_sub_cancel_left]
Further results on `List.take` and `List.drop`, which rely on stronger automation in `Nat`,
are given in `Init.Data.List.TakeDrop`.
-/
@[simp]
theorem take_eq_take :
{l : List α} {m n : Nat}, l.take m = l.take n min m l.length = min n l.length
| [], m, n => by simp [Nat.min_zero]
| _ :: xs, 0, 0 => by simp
| x :: xs, m + 1, 0 => by simp [Nat.zero_min, succ_min_succ]
| x :: xs, 0, n + 1 => by simp [Nat.zero_min, succ_min_succ]
| x :: xs, m + 1, n + 1 => by simp [succ_min_succ, take_eq_take]
theorem drop_one : l : List α, drop 1 l = tail l
| [] | _ :: _ => rfl
theorem take_add (l : List α) (m n : Nat) : l.take (m + n) = l.take m ++ (l.drop m).take n := by
suffices take (m + n) (take m l ++ drop m l) = take m l ++ take n (drop m l) by
rw [take_append_drop] at this
assumption
rw [take_append_eq_append_take, take_of_length_le, append_right_inj]
· simp only [take_eq_take, length_take, length_drop]
omega
apply Nat.le_trans (m := m)
· apply length_take_le
· apply Nat.le_add_right
@[simp] theorem take_append_drop : (n : Nat) (l : List α), take n l ++ drop n l = l
| 0, _ => rfl
| _+1, [] => rfl
| n+1, x :: xs => congrArg (cons x) <| take_append_drop n xs
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]
@[simp] theorem length_drop : (i : Nat) (l : List α), length (drop i l) = length l - i
| 0, _ => rfl
| succ i, [] => Eq.symm (Nat.zero_sub (succ i))
| succ i, x :: l => calc
length (drop (succ i) (x :: l)) = length l - i := length_drop i l
_ = succ (length l) - succ i := (Nat.succ_sub_succ_eq_sub (length l) i).symm
theorem map_eq_append_split {f : α β} {l : List α} {s₁ s₂ : List β}
(h : map f l = s₁ ++ s₂) : l₁ l₂, l = l₁ ++ l₂ map f l₁ = s₁ map f l₂ = s₂ := by
have := h
rw [ take_append_drop (length s₁) l] at this
rw [map_append] at this
refine _, _, rfl, append_inj this ?_
rw [length_map, length_take, Nat.min_eq_left]
rw [ length_map l f, h, length_append]
apply Nat.le_add_right
theorem drop_of_length_le {l : List α} (h : l.length i) : drop i l = [] :=
length_eq_zero.1 (length_drop .. Nat.sub_eq_zero_of_le h)
/-! ### drop -/
theorem length_lt_of_drop_ne_nil {l : List α} {n} (h : drop n l []) : n < l.length :=
gt_of_not_le (mt drop_of_length_le h)
theorem lt_length_drop (L : List α) {i j : Nat} (h : i + j < L.length) : j < (L.drop i).length := by
have A : i < L.length := Nat.lt_of_le_of_lt (Nat.le.intro rfl) h
rw [(take_append_drop i L).symm] at h
simpa only [Nat.le_of_lt A, Nat.min_eq_left, Nat.add_lt_add_iff_left, length_take,
length_append] using h
theorem take_of_length_le {l : List α} (h : l.length i) : take i l = l := by
have := take_append_drop i l
rw [drop_of_length_le h, append_nil] at this; exact this
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the big list to the small list. -/
theorem getElem_drop (L : List α) {i j : Nat} (h : i + j < L.length) :
L[i + j] = (L.drop i)[j]'(lt_length_drop L h) := by
have : i L.length := Nat.le_trans (Nat.le_add_right _ _) (Nat.le_of_lt h)
rw [getElem_of_eq (take_append_drop i L).symm h, getElem_append_right'] <;>
simp [Nat.min_eq_left this, Nat.add_sub_cancel_left, Nat.le_add_right]
theorem lt_length_of_take_ne_self {l : List α} {n} (h : l.take n l) : n < l.length :=
gt_of_not_le (mt take_of_length_le h)
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the big list to the small list. -/
@[deprecated getElem_drop (since := "2024-06-12")]
theorem get_drop (L : List α) {i j : Nat} (h : i + j < L.length) :
get L i + j, h = get (L.drop i) j, lt_length_drop L h := by
simp [getElem_drop]
@[deprecated drop_of_length_le (since := "2024-07-07")] abbrev drop_length_le := @drop_of_length_le
@[deprecated take_of_length_le (since := "2024-07-07")] abbrev take_length_le := @take_of_length_le
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the small list to the big list. -/
theorem getElem_drop' (L : List α) {i : Nat} {j : Nat} {h : j < (L.drop i).length} :
(L.drop i)[j] = L[i + j]'(by
rw [Nat.add_comm]
exact Nat.add_lt_of_lt_sub (length_drop i L h)) := by
rw [getElem_drop]
@[simp] theorem drop_length (l : List α) : drop l.length l = [] := drop_of_length_le (Nat.le_refl _)
/-- The `i + j`-th element of a list coincides with the `j`-th element of the list obtained by
dropping the first `i` elements. Version designed to rewrite from the small list to the big list. -/
@[deprecated getElem_drop' (since := "2024-06-12")]
theorem get_drop' (L : List α) {i j} :
get (L.drop i) j = get L i + j, by
rw [Nat.add_comm]
exact Nat.add_lt_of_lt_sub (length_drop i L j.2) := by
simp [getElem_drop']
@[simp] theorem take_length (l : List α) : take l.length l = l := take_of_length_le (Nat.le_refl _)
@[simp]
theorem getElem?_drop (L : List α) (i j : Nat) : (L.drop i)[j]? = L[i + j]? := by
ext
simp only [getElem?_eq_some, getElem_drop', Option.mem_def]
constructor <;> intro h, ha
· exact _, ha
· refine ?_, ha
rw [length_drop]
rw [Nat.add_comm] at h
apply Nat.lt_sub_of_add_lt h
theorem getElem_cons_drop : (l : List α) (i : Nat) (h : i < l.length),
l[i] :: drop (i + 1) l = drop i l
| _::_, 0, _ => rfl
| _::_, i+1, _ => getElem_cons_drop _ i _
@[deprecated getElem?_drop (since := "2024-06-12")]
theorem get?_drop (L : List α) (i j : Nat) : get? (L.drop i) j = get? L (i + j) := by
@[deprecated getElem_cons_drop (since := "2024-06-12")]
theorem get_cons_drop (l : List α) (i) : get l i :: drop (i + 1) l = drop i l := by
simp
theorem head?_drop (l : List α) (n : Nat) :
(l.drop n).head? = l[n]? := by
rw [head?_eq_getElem?, getElem?_drop, Nat.add_zero]
theorem drop_eq_getElem_cons {n} {l : List α} (h) : drop n l = l[n] :: drop (n + 1) l :=
(getElem_cons_drop _ n h).symm
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
simpa [head?_eq_head, getElem?_eq_getElem, h, w] using head?_drop l n
@[deprecated drop_eq_getElem_cons (since := "2024-06-12")]
theorem drop_eq_get_cons {n} {l : List α} (h) : drop n l = get l n, h :: drop (n + 1) l := by
simp [drop_eq_getElem_cons]
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]
rw [length_drop]
split
· rw [getElem?_eq_none (by omega)]
· rw [getLast?_eq_getElem?]
congr
omega
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_le] at h
apply Option.some_inj.1
simp only [ getLast?_eq_getLast, getLast?_drop, ite_eq_right_iff]
omega
theorem drop_length_cons {l : List α} (h : l []) (a : α) :
(a :: l).drop l.length = [l.getLast h] := by
induction l generalizing a with
| nil =>
cases h rfl
| cons y l ih =>
simp only [drop, length]
by_cases h₁ : l = []
· simp [h₁]
rw [getLast_cons h₁]
exact ih h₁ y
/-- Dropping the elements up to `n` in `l₁ ++ l₂` is the same as dropping the elements up to `n`
in `l₁`, dropping the elements up to `n - l₁.length` in `l₂`, and appending them. -/
theorem drop_append_eq_append_drop {l₁ l₂ : List α} {n : Nat} :
drop n (l₁ ++ l₂) = drop n l₁ ++ drop (n - l₁.length) l₂ := by
induction l₁ generalizing n
· simp
· cases n
· simp [*]
· simp only [cons_append, drop_succ_cons, length_cons, succ_eq_add_one, append_cancel_left_eq, *]
congr 1
omega
theorem drop_append_of_le_length {l₁ l₂ : List α} {n : Nat} (h : n l₁.length) :
(l₁ ++ l₂).drop n = l₁.drop n ++ l₂ := by
simp [drop_append_eq_append_drop, Nat.sub_eq_zero_of_le h]
/-- Dropping the elements up to `l₁.length + i` in `l₁ + l₂` is the same as dropping the elements
up to `i` in `l₂`. -/
@[simp]
theorem drop_append {l l₂ : List α} (i : Nat) : drop (l₁.length + i) (l₁ ++ l₂) = drop i l₂ := by
rw [drop_append_eq_append_drop, drop_eq_nil_of_le] <;>
simp [Nat.add_sub_cancel_left, Nat.le_add_right]
theorem getElem?_take {l : List α} {n m : Nat} (h : m < n) : (l.take n)[m]? = l[m]? := by
induction n generalizing l m with
| zero =>
exact absurd h (Nat.not_lt_of_le m.zero_le)
| succ _ hn =>
cases l with
| nil => simp only [take_nil]
| cons hd tl =>
cases m
· simp
· simpa using hn (Nat.lt_of_succ_lt_succ h)
theorem set_eq_take_append_cons_drop {l : List α} {n : Nat} {a : α} :
l.set n a = if n < l.length then l.take n ++ a :: l.drop (n + 1) else l := by
split <;> rename_i h
· ext1 m
by_cases h' : m < n
· rw [getElem?_append (by simp [length_take]; omega), getElem?_set_ne (by omega),
getElem?_take h']
· by_cases h'' : m = n
· subst h''
rw [getElem?_set_eq _, getElem?_append_right, length_take,
Nat.min_eq_left (by omega), Nat.sub_self, getElem?_cons_zero]
rw [length_take]
exact Nat.min_le_left m l.length
· have h''' : n < m := by omega
rw [getElem?_set_ne (by omega), getElem?_append_right, length_take,
Nat.min_eq_left (by omega)]
· obtain k, rfl := Nat.exists_eq_add_of_lt h'''
have p : n + k + 1 - n = k + 1 := by omega
rw [p]
rw [getElem?_cons_succ, getElem?_drop]
congr 1
omega
· rw [length_take]
exact Nat.le_trans (Nat.min_le_left _ _) (by omega)
· rw [set_eq_of_length_le]
omega
@[deprecated getElem?_take (since := "2024-06-12")]
theorem get?_take {l : List α} {n m : Nat} (h : m < n) : (l.take n).get? m = l.get? m := by
simp [getElem?_take, h]
theorem exists_of_set {n : Nat} {a' : α} {l : List α} (h : n < l.length) :
l₁ l₂, l = l₁ ++ l[n] :: l₂ l.length = n l.set n a' = l₁ ++ a' :: l₂ := by
refine l.take n, l.drop (n + 1), by simp, length_take_of_le (Nat.le_of_lt h), ?_
simp [set_eq_take_append_cons_drop, h]
@[simp]
theorem getElem?_take_of_succ {l : List α} {n : Nat} : (l.take (n + 1))[n]? = l[n]? :=
getElem?_take (Nat.lt_succ_self n)
theorem drop_set_of_lt (a : α) {n m : Nat} (l : List α)
(hnm : n < m) : drop m (l.set n a) = l.drop m :=
ext_getElem? fun k => by simpa only [getElem?_drop] using getElem?_set_ne (by omega)
theorem tail_drop (l : List α) (n : Nat) : (l.drop n).tail = l.drop (n + 1) := by
induction l generalizing n with
| nil => simp
| cons hd tl hl =>
cases n
· simp
· simp [hl]
theorem drop_take : (m n : Nat) (l : List α), drop n (take m l) = take (m - n) (drop n l)
@[simp]
theorem drop_eq_nil_iff_le {l : List α} {k : Nat} : l.drop k = [] l.length k := by
refine' fun h => _, drop_eq_nil_of_le
induction k generalizing l with
| zero =>
simp only [drop] at h
simp [h]
| succ k hk =>
cases l
· simp
· simp only [drop] at h
simpa [Nat.succ_le_succ_iff] using hk h
@[simp]
theorem take_eq_nil_iff {l : List α} {k : Nat} : l.take k = [] k = 0 l = [] := by
cases l <;> cases k <;> simp [Nat.succ_ne_zero]
theorem drop_eq_nil_of_eq_nil : {as : List α} {i}, as = [] as.drop i = []
| _, _, rfl => drop_nil
theorem ne_nil_of_drop_ne_nil {as : List α} {i : Nat} (h: as.drop i []) : as [] :=
mt drop_eq_nil_of_eq_nil h
theorem take_eq_nil_of_eq_nil : {as : List α} {i}, as = [] as.take i = []
| _, _, rfl => take_nil
theorem ne_nil_of_take_ne_nil {as : List α} {i : Nat} (h : as.take i []) : as [] :=
mt take_eq_nil_of_eq_nil h
theorem set_take {l : List α} {n m : Nat} {a : α} :
(l.set m a).take n = (l.take n).set m a := by
induction n generalizing l m with
| zero => simp
| succ _ hn =>
cases l with
| nil => simp
| cons hd tl => cases m <;> simp_all
theorem drop_set {l : List α} {n m : Nat} {a : α} :
(l.set m a).drop n = if m < n then l.drop n else (l.drop n).set (m - n) a := by
induction n generalizing l m with
| zero => simp
| succ _ hn =>
cases l with
| nil => simp
| cons hd tl =>
cases m
· simp_all
· simp only [hn, set_cons_succ, drop_succ_cons, succ_lt_succ_iff]
congr 2
exact (Nat.add_sub_add_right ..).symm
theorem set_drop {l : List α} {n m : Nat} {a : α} :
(l.drop n).set m a = (l.set (n + m) a).drop n := by
rw [drop_set, if_neg, add_sub_self_left n m]
exact (Nat.not_lt).2 (le_add_right n m)
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, 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
@[deprecated take_of_length_le (since := "2024-07-25")]
theorem take_all_of_le {n} {l : List α} (h : length l n) : take n l = l :=
take_of_length_le h
theorem drop_left : l₁ l₂ : List α, drop (length l₁) (l₁ ++ l₂) = l₂
| [], _ => rfl
| _ :: l₁, l₂ => drop_left l₁ l₂
@[simp]
theorem drop_left' {l₁ l₂ : List α} {n} (h : length l₁ = n) : drop n (l₁ ++ l₂) = l₂ := by
rw [ h]; apply drop_left
theorem take_left : l₁ l₂ : List α, take (length l₁) (l₁ ++ l₂) = l₁
| [], _ => rfl
| a :: l₁, l₂ => congrArg (cons a) (take_left l₁ l₂)
@[simp]
theorem take_left' {l₁ l₂ : List α} {n} (h : length l₁ = n) : take n (l₁ ++ l₂) = l₁ := by
rw [ h]; apply take_left
theorem take_succ {l : List α} {n : Nat} : l.take (n + 1) = l.take n ++ l[n]?.toList := by
induction l generalizing n with
| nil =>
simp only [take_nil, Option.toList, getElem?_nil, append_nil]
| cons hd tl hl =>
cases n
· simp only [take, Option.toList, getElem?_cons_zero, nil_append]
· simp only [take, hl, getElem?_cons_succ, cons_append]
@[deprecated (since := "2024-07-25")]
theorem drop_sizeOf_le [SizeOf α] (l : List α) (n : Nat) : sizeOf (l.drop n) sizeOf l := by
induction l generalizing n with
| nil => rw [drop_nil]; apply Nat.le_refl
| cons _ _ lih =>
induction n with
| zero => apply Nat.le_refl
| succ n =>
exact Trans.trans (lih _) (Nat.le_add_left _ _)
theorem dropLast_eq_take (l : List α) : l.dropLast = l.take (l.length - 1) := by
cases l with
| nil => simp [dropLast]
| cons x l =>
induction l generalizing x <;> simp_all [dropLast]
@[simp] theorem map_take (f : α β) :
(L : List α) (i : Nat), (L.take i).map f = (L.map f).take i
| [], i => by simp
| _, 0 => by simp
| h :: t, n + 1 => by dsimp; rw [map_take f t n]
@[simp] theorem map_drop (f : α β) :
(L : List α) (i : Nat), (L.drop i).map f = (L.map f).drop i
| [], i => by simp
| L, 0 => by simp
| h :: t, n + 1 => by
dsimp
rw [map_drop f t]
@[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 (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
| _, 0, _ => by simp
| _, _, [] => by simp
| m+1, n+1, h :: t => by
simp [take_succ_cons, drop_succ_cons, drop_take m n t]
congr 1
omega
| _+1, _, _ :: _ => by simpa [Nat.succ_add, take_succ_cons, drop_succ_cons] using take_drop ..
theorem take_reverse {α} {xs : List α} {n : Nat} (h : n xs.length) :
xs.reverse.take n = (xs.drop (xs.length - n)).reverse := by
induction xs generalizing n <;>
simp only [reverse_cons, drop, reverse_nil, Nat.zero_sub, length, take_nil]
next xs_hd xs_tl xs_ih =>
cases Nat.lt_or_eq_of_le h with
| inl h' =>
have h' := Nat.le_of_succ_le_succ h'
rw [take_append_of_le_length, xs_ih h']
rw [show xs_tl.length + 1 - n = succ (xs_tl.length - n) from _, drop]
· rwa [succ_eq_add_one, Nat.sub_add_comm]
· rwa [length_reverse]
| inr h' =>
subst h'
rw [length, Nat.sub_self, drop]
suffices xs_tl.length + 1 = (xs_tl.reverse ++ [xs_hd]).length by
rw [this, take_length, reverse_cons]
rw [length_append, length_reverse]
rfl
@[deprecated drop_drop (since := "2024-06-15")]
theorem drop_add (m n) (l : List α) : drop (m + n) l = drop m (drop n l) := by
simp [drop_drop]
@[deprecated (since := "2024-06-15")] abbrev reverse_take := @take_reverse
/-! ### takeWhile and dropWhile -/
theorem drop_reverse {α} {xs : List α} {n : Nat} (h : n xs.length) :
xs.reverse.drop n = (xs.take (xs.length - n)).reverse := by
conv =>
rhs
rw [ reverse_reverse xs]
rw [ reverse_reverse xs] at h
generalize xs.reverse = xs' at h
rw [take_reverse]
· simp only [length_reverse, reverse_reverse] at *
congr
omega
· simp only [length_reverse, sub_le]
theorem takeWhile_cons (p : α Bool) (a : α) (l : List α) :
(a :: l).takeWhile p = if p a then a :: l.takeWhile p else [] := by
simp only [takeWhile]
by_cases h: p a <;> simp [h]
@[simp] theorem takeWhile_cons_of_pos {p : α Bool} {a : α} {l : List α} (h : p a) :
(a :: l).takeWhile p = a :: l.takeWhile p := by
simp [takeWhile_cons, h]
@[simp] theorem takeWhile_cons_of_neg {p : α Bool} {a : α} {l : List α} (h : ¬ p a) :
(a :: l).takeWhile p = [] := by
simp [takeWhile_cons, h]
theorem dropWhile_cons :
(x :: xs : List α).dropWhile p = if p x then xs.dropWhile p else x :: xs := by
split <;> simp_all [dropWhile]
@[simp] theorem dropWhile_cons_of_pos {a : α} {l : List α} (h : p a) :
(a :: l).dropWhile p = l.dropWhile p := by
simp [dropWhile_cons, h]
@[simp] theorem dropWhile_cons_of_neg {a : α} {l : List α} (h : ¬ p a) :
(a :: l).dropWhile p = a :: l := by
simp [dropWhile_cons, h]
theorem head?_takeWhile (p : α Bool) (l : List α) : (l.takeWhile p).head? = l.head?.filter p := by
cases l with
| nil => rfl
| cons x xs =>
simp only [takeWhile_cons, head?_cons, Option.filter_some]
split <;> simp
theorem head_takeWhile (p : α Bool) (l : List α) (w) :
(l.takeWhile p).head w = l.head (by rintro rfl; simp_all) := by
cases l with
| nil => rfl
| cons x xs =>
simp only [takeWhile_cons, head_cons]
simp only [takeWhile_cons] at w
split <;> simp_all
theorem head?_dropWhile_not (p : α Bool) (l : List α) :
match (l.dropWhile p).head? with | some x => p x = false | none => True := by
induction l with
| nil => simp
| cons x xs ih =>
simp only [dropWhile_cons]
split <;> rename_i h <;> split at h <;> simp_all
theorem head_dropWhile_not (p : α Bool) (l : List α) (w) :
p ((l.dropWhile p).head w) = false := by
simpa [head?_eq_head, w] using head?_dropWhile_not p l
theorem takeWhile_map (f : α β) (p : β Bool) (l : List α) :
(l.map f).takeWhile p = (l.takeWhile (p f)).map f := by
induction l with
| nil => rfl
| cons x xs ih =>
simp only [map_cons, takeWhile_cons]
split <;> simp_all
theorem dropWhile_map (f : α β) (p : β Bool) (l : List α) :
(l.map f).dropWhile p = (l.dropWhile (p f)).map f := by
induction l with
| nil => rfl
| cons x xs ih =>
simp only [map_cons, dropWhile_cons]
split <;> simp_all
theorem takeWhile_filterMap (f : α Option β) (p : β Bool) (l : List α) :
(l.filterMap f).takeWhile p = (l.takeWhile fun a => (f a).all p).filterMap f := by
induction l with
| nil => rfl
| cons x xs ih =>
simp only [filterMap_cons]
split <;> rename_i h
· simp only [takeWhile_cons, h]
split <;> simp_all
· simp [takeWhile_cons, h, ih]
split <;> simp_all [filterMap_cons]
theorem dropWhile_filterMap (f : α Option β) (p : β Bool) (l : List α) :
(l.filterMap f).dropWhile p = (l.dropWhile fun a => (f a).all p).filterMap f := by
induction l with
| nil => rfl
| cons x xs ih =>
simp only [filterMap_cons]
split <;> rename_i h
· simp only [dropWhile_cons, h]
split <;> simp_all
· simp [dropWhile_cons, h, ih]
split <;> simp_all [filterMap_cons]
theorem takeWhile_filter (p q : α Bool) (l : List α) :
(l.filter p).takeWhile q = (l.takeWhile fun a => !p a || q a).filter p := by
simp [ filterMap_eq_filter, takeWhile_filterMap]
theorem dropWhile_filter (p q : α Bool) (l : List α) :
(l.filter p).dropWhile q = (l.dropWhile fun a => !p a || q a).filter p := by
simp [ filterMap_eq_filter, dropWhile_filterMap]
@[simp] theorem takeWhile_append_dropWhile (p : α Bool) :
(l : List α), takeWhile p l ++ dropWhile p l = l
| [] => rfl
| x :: xs => by simp [takeWhile, dropWhile]; cases p x <;> simp [takeWhile_append_dropWhile p xs]
theorem takeWhile_append {xs ys : List α} :
(xs ++ ys).takeWhile p =
if (xs.takeWhile p).length = xs.length then xs ++ ys.takeWhile p else xs.takeWhile p := by
induction xs with
| nil => simp
| cons x xs ih =>
simp only [cons_append, takeWhile_cons]
split
· simp_all only [length_cons, add_one_inj]
split <;> rfl
· simp_all
@[simp] theorem takeWhile_append_of_pos {p : α Bool} {l₁ l₂ : List α} (h : a l₁, p a) :
(l₁ ++ l₂).takeWhile p = l₁ ++ l₂.takeWhile p := by
induction l₁ with
| nil => simp
| cons x xs ih => simp_all [takeWhile_cons]
theorem dropWhile_append {xs ys : List α} :
(xs ++ ys).dropWhile p =
if (xs.dropWhile p).isEmpty then ys.dropWhile p else xs.dropWhile p ++ ys := by
induction xs with
| nil => simp
| cons h t ih =>
simp only [cons_append, dropWhile_cons]
split <;> simp_all
@[simp] theorem dropWhile_append_of_pos {p : α Bool} {l₁ l₂ : List α} (h : a l₁, p a) :
(l₁ ++ l₂).dropWhile p = l₂.dropWhile p := by
induction l₁ with
| nil => simp
| cons x xs ih => simp_all [dropWhile_cons]
@[simp] theorem takeWhile_replicate_eq_filter (p : α Bool) :
(replicate n a).takeWhile p = (replicate n a).filter p := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate_succ, takeWhile_cons]
split <;> simp_all
theorem takeWhile_replicate (p : α Bool) :
(replicate n a).takeWhile p = if p a then replicate n a else [] := by
rw [takeWhile_replicate_eq_filter, filter_replicate]
@[simp] theorem dropWhile_replicate_eq_filter_not (p : α Bool) :
(replicate n a).dropWhile p = (replicate n a).filter (fun a => !p a) := by
induction n with
| zero => simp
| succ n ih =>
simp only [replicate_succ, dropWhile_cons]
split <;> simp_all
theorem dropWhile_replicate (p : α Bool) :
(replicate n a).dropWhile p = if p a then [] else replicate n a := by
simp only [dropWhile_replicate_eq_filter_not, filter_replicate]
split <;> simp_all
theorem take_takeWhile {l : List α} (p : α Bool) n :
(l.takeWhile p).take n = (l.take n).takeWhile p := by
induction l generalizing n with
| nil => simp
| cons x xs ih =>
by_cases h : p x <;> cases n <;> simp [takeWhile_cons, h, ih, take_succ_cons]
@[simp] theorem all_takeWhile {l : List α} : (l.takeWhile p).all p = true := by
induction l with
| nil => rfl
| cons h t ih => by_cases p h <;> simp_all
@[simp] theorem any_dropWhile {l : List α} :
(l.dropWhile p).any (fun x => !p x) = !l.all p := by
induction l with
| nil => rfl
| cons h t ih => by_cases p h <;> simp_all
/-! ### rotateLeft -/
@[simp] theorem rotateLeft_replicate (n) (a : α) : rotateLeft (replicate m a) n = replicate m a := by
cases n with
| zero => simp
| succ n =>
suffices 1 < m m - (n + 1) % m + min ((n + 1) % m) m = m by
simpa [rotateLeft]
intro h
rw [Nat.min_eq_left (Nat.le_of_lt (Nat.mod_lt _ (by omega)))]
have : (n + 1) % m < m := Nat.mod_lt _ (by omega)
omega
@[simp] theorem rotateLeft_zero (l : List α) : rotateLeft l 0 = l := by
simp [rotateLeft]
-- TODO Batteries defines its own `getElem?_rotate`, which we need to adapt.
-- TODO Prove `map_rotateLeft`, using `ext` and `getElem?_rotateLeft`.
/-! ### rotateRight -/
@[simp] theorem rotateRight_replicate (n) (a : α) : rotateRight (replicate m a) n = replicate m a := by
cases n with
| zero => simp
| succ n =>
suffices 1 < m m - (m - (n + 1) % m) + min (m - (n + 1) % m) m = m by
simpa [rotateRight]
intro h
have : (n + 1) % m < m := Nat.mod_lt _ (by omega)
rw [Nat.min_eq_left (by omega)]
omega
@[simp] theorem rotateRight_zero (l : List α) : rotateRight l 0 = l := by
simp [rotateRight]
/-! ### zipWith -/
@[simp] theorem length_zipWith (f : α β γ) (l₁ l₂) :
length (zipWith f l₁ l₂) = min (length l₁) (length l₂) := by
induction l₁ generalizing l₂ <;> cases l₂ <;>
simp_all [succ_min_succ, Nat.zero_min, Nat.min_zero]
theorem lt_length_left_of_zipWith {f : α β γ} {i : Nat} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l.length := by rw [length_zipWith] at h; omega
theorem lt_length_right_of_zipWith {f : α β γ} {i : Nat} {l : List α} {l' : List β}
(h : i < (zipWith f l l').length) : i < l'.length := by rw [length_zipWith] at h; omega
@[simp]
theorem getElem_zipWith {f : α β γ} {l : List α} {l' : List β}
{i : Nat} {h : i < (zipWith f l l').length} :
(zipWith f l l')[i] =
f (l[i]'(lt_length_left_of_zipWith h))
(l'[i]'(lt_length_right_of_zipWith h)) := by
rw [ Option.some_inj, getElem?_eq_getElem, getElem?_zipWith_eq_some]
exact
l[i]'(lt_length_left_of_zipWith h), l'[i]'(lt_length_right_of_zipWith h),
by rw [getElem?_eq_getElem], by rw [getElem?_eq_getElem]; exact rfl, rfl
theorem zipWith_eq_zipWith_take_min : (l₁ : List α) (l₂ : List β),
zipWith f l₁ l₂ = zipWith f (l₁.take (min l₁.length l₂.length)) (l₂.take (min l₁.length l₂.length))
| [], _ => by simp
| _, [] => by simp
| a :: l₁, b :: l₂ => by simp [succ_min_succ, zipWith_eq_zipWith_take_min l₁ l₂]
theorem reverse_zipWith (h : l.length = l'.length) :
(zipWith f l l').reverse = zipWith f l.reverse l'.reverse := by
induction l generalizing l' with
| nil => simp
| cons hd tl hl =>
cases l' with
| nil => simp
| cons hd' tl' =>
simp only [Nat.add_right_cancel_iff, length] at h
have : tl.reverse.length = tl'.reverse.length := by simp [h]
simp [hl h, zipWith_append _ _ _ _ _ this]
@[deprecated reverse_zipWith (since := "2024-07-28")] abbrev zipWith_distrib_reverse := @reverse_zipWith
@[simp] theorem zipWith_replicate {a : α} {b : β} {m n : Nat} :
zipWith f (replicate m a) (replicate n b) = replicate (min m n) (f a b) := by
rw [zipWith_eq_zipWith_take_min]
simp
/-! ### zip -/
@[simp] theorem length_zip (l₁ : List α) (l₂ : List β) :
length (zip l₁ l₂) = min (length l₁) (length l₂) := by
simp [zip]
theorem lt_length_left_of_zip {i : Nat} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l.length :=
lt_length_left_of_zipWith h
theorem lt_length_right_of_zip {i : Nat} {l : List α} {l' : List β} (h : i < (zip l l').length) :
i < l'.length :=
lt_length_right_of_zipWith h
@[simp]
theorem getElem_zip {l : List α} {l' : List β} {i : Nat} {h : i < (zip l l').length} :
(zip l l')[i] =
(l[i]'(lt_length_left_of_zip h), l'[i]'(lt_length_right_of_zip h)) :=
getElem_zipWith (h := h)
theorem zip_eq_zip_take_min : (l₁ : List α) (l₂ : List β),
zip l₁ l₂ = zip (l₁.take (min l₁.length l₂.length)) (l₂.take (min l₁.length l₂.length))
| [], _ => by simp
| _, [] => by simp
| a :: l₁, b :: l₂ => by simp [succ_min_succ, zip_eq_zip_take_min l₁ l₂]
@[simp] theorem zip_replicate {a : α} {b : β} {m n : Nat} :
zip (replicate m a) (replicate n b) = replicate (min m n) (a, b) := by
rw [zip_eq_zip_take_min]
simp
-- TODO Batteries defines its own `getElem?_rotate`, which we need to adapt.
-- TODO Prove `map_rotateRight`, using `ext` and `getElem?_rotateRight`.
end List

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/-
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.TakeDrop
/-!
# Lemmas about `List.zip`, `List.zipWith`, `List.zipWithAll`, and `List.unzip`.
-/
namespace List
open Nat
/-! ## Zippers -/
/-! ### zip -/
theorem zip_map (f : α γ) (g : β δ) :
(l₁ : List α) (l₂ : List β), zip (l₁.map f) (l₂.map g) = (zip l₁ l₂).map (Prod.map f g)
| [], l₂ => rfl
| l₁, [] => by simp only [map, zip_nil_right]
| a :: l₁, b :: l₂ => by
simp only [map, zip_cons_cons, zip_map, Prod.map]; constructor
theorem zip_map_left (f : α γ) (l₁ : List α) (l₂ : List β) :
zip (l₁.map f) l₂ = (zip l₁ l₂).map (Prod.map f id) := by rw [ zip_map, map_id]
theorem zip_map_right (f : β γ) (l₁ : List α) (l₂ : List β) :
zip l₁ (l₂.map f) = (zip l₁ l₂).map (Prod.map id f) := by rw [ zip_map, map_id]
theorem zip_append :
{l₁ r₁ : List α} {l₂ r₂ : List β} (_h : length l₁ = length l₂),
zip (l₁ ++ r₁) (l₂ ++ r₂) = zip l₁ l₂ ++ zip r₁ r₂
| [], r₁, l₂, r₂, h => by simp only [eq_nil_of_length_eq_zero h.symm]; rfl
| l₁, r₁, [], r₂, h => by simp only [eq_nil_of_length_eq_zero h]; rfl
| a :: l₁, r₁, b :: l₂, r₂, h => by
simp only [cons_append, zip_cons_cons, zip_append (Nat.succ.inj h)]
theorem zip_map' (f : α β) (g : α γ) :
l : List α, zip (l.map f) (l.map g) = l.map fun a => (f a, g a)
| [] => rfl
| a :: l => by simp only [map, zip_cons_cons, zip_map']
theorem of_mem_zip {a b} : {l₁ : List α} {l₂ : List β}, (a, b) zip l₁ l₂ a l₁ b l₂
| _ :: l₁, _ :: l₂, h => by
cases h
case head => simp
case tail h =>
· have := of_mem_zip h
exact Mem.tail _ this.1, Mem.tail _ this.2
@[deprecated of_mem_zip (since := "2024-07-28")] abbrev mem_zip := @of_mem_zip
theorem map_fst_zip :
(l₁ : List α) (l₂ : List β), l₁.length l₂.length map Prod.fst (zip l₁ l₂) = l₁
| [], bs, _ => rfl
| _ :: as, _ :: bs, h => by
simp [Nat.succ_le_succ_iff] at h
show _ :: map Prod.fst (zip as bs) = _ :: as
rw [map_fst_zip as bs h]
| a :: as, [], h => by simp at h
theorem map_snd_zip :
(l₁ : List α) (l₂ : List β), l₂.length l₁.length map Prod.snd (zip l₁ l₂) = l₂
| _, [], _ => by
rw [zip_nil_right]
rfl
| [], b :: bs, h => by simp at h
| a :: as, b :: bs, h => by
simp [Nat.succ_le_succ_iff] at h
show _ :: map Prod.snd (zip as bs) = _ :: bs
rw [map_snd_zip as bs h]
theorem map_prod_left_eq_zip {l : List α} (f : α β) :
(l.map fun x => (x, f x)) = l.zip (l.map f) := by
rw [ zip_map']
congr
exact map_id _
theorem map_prod_right_eq_zip {l : List α} (f : α β) :
(l.map fun x => (f x, x)) = (l.map f).zip l := by
rw [ zip_map']
congr
exact map_id _
/-- See also `List.zip_replicate` in `Init.Data.List.TakeDrop` for a generalization with different lengths. -/
@[simp] theorem zip_replicate' {a : α} {b : β} {n : Nat} :
zip (replicate n a) (replicate n b) = replicate n (a, b) := by
induction n with
| zero => rfl
| succ n ih => simp [replicate_succ, ih]
/-! ### zipWith -/
theorem zipWith_comm (f : α β γ) :
(la : List α) (lb : List β), zipWith f la lb = zipWith (fun b a => f a b) lb la
| [], _ => List.zipWith_nil_right.symm
| _ :: _, [] => rfl
| _ :: as, _ :: bs => congrArg _ (zipWith_comm f as bs)
theorem zipWith_comm_of_comm (f : α α β) (comm : x y : α, f x y = f y x) (l l' : List α) :
zipWith f l l' = zipWith f l' l := by
rw [zipWith_comm]
simp only [comm]
@[simp]
theorem zipWith_same (f : α α δ) : l : List α, zipWith f l l = l.map fun a => f a a
| [] => rfl
| _ :: xs => congrArg _ (zipWith_same f xs)
/--
See also `getElem?_zipWith'` for a variant
using `Option.map` and `Option.bind` rather than a `match`.
-/
theorem getElem?_zipWith {f : α β γ} {i : Nat} :
(List.zipWith f as bs)[i]? = match as[i]?, bs[i]? with
| some a, some b => some (f a b) | _, _ => none := by
induction as generalizing bs i with
| nil => cases bs with
| nil => simp
| cons b bs => simp
| cons a as aih => cases bs with
| nil => simp
| cons b bs => cases i <;> simp_all
/-- Variant of `getElem?_zipWith` using `Option.map` and `Option.bind` rather than a `match`. -/
theorem getElem?_zipWith' {f : α β γ} {i : Nat} :
(zipWith f l₁ l₂)[i]? = (l₁[i]?.map f).bind fun g => l₂[i]?.map g := by
induction l₁ generalizing l₂ i with
| nil => rw [zipWith] <;> simp
| cons head tail =>
cases l₂
· simp
· cases i <;> simp_all
theorem getElem?_zipWith_eq_some (f : α β γ) (l₁ : List α) (l₂ : List β) (z : γ) (i : Nat) :
(zipWith f l₁ l₂)[i]? = some z
x y, l₁[i]? = some x l₂[i]? = some y f x y = z := by
induction l₁ generalizing l₂ i
· simp
· cases l₂ <;> cases i <;> simp_all
theorem getElem?_zip_eq_some (l₁ : List α) (l₂ : List β) (z : α × β) (i : Nat) :
(zip l₁ l₂)[i]? = some z l₁[i]? = some z.1 l₂[i]? = some z.2 := by
cases z
rw [zip, getElem?_zipWith_eq_some]; constructor
· rintro x, y, h₀, h₁, h₂
simpa [h₀, h₁] using h₂
· rintro h₀, h₁
exact _, _, h₀, h₁, rfl
@[deprecated getElem?_zipWith (since := "2024-06-12")]
theorem get?_zipWith {f : α β γ} :
(List.zipWith f as bs).get? i = match as.get? i, bs.get? i with
| some a, some b => some (f a b) | _, _ => none := by
simp [getElem?_zipWith]
set_option linter.deprecated false in
@[deprecated getElem?_zipWith (since := "2024-06-07")] abbrev zipWith_get? := @get?_zipWith
theorem head?_zipWith {f : α β γ} :
(List.zipWith f as bs).head? = match as.head?, bs.head? with
| some a, some b => some (f a b) | _, _ => none := by
simp [head?_eq_getElem?, getElem?_zipWith]
theorem head_zipWith {f : α β γ} (h):
(List.zipWith f as bs).head h = f (as.head (by rintro rfl; simp_all)) (bs.head (by rintro rfl; simp_all)) := by
apply Option.some.inj
rw [ head?_eq_head, head?_zipWith, head?_eq_head, head?_eq_head]
@[simp]
theorem zipWith_map {μ} (f : γ δ μ) (g : α γ) (h : β δ) (l₁ : List α) (l₂ : List β) :
zipWith f (l₁.map g) (l₂.map h) = zipWith (fun a b => f (g a) (h b)) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWith_map_left (l₁ : List α) (l₂ : List β) (f : α α') (g : α' β γ) :
zipWith g (l₁.map f) l₂ = zipWith (fun a b => g (f a) b) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWith_map_right (l₁ : List α) (l₂ : List β) (f : β β') (g : α β' γ) :
zipWith g l₁ (l₂.map f) = zipWith (fun a b => g a (f b)) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWith_foldr_eq_zip_foldr {f : α β γ} (i : δ):
(zipWith f l₁ l₂).foldr g i = (zip l₁ l₂).foldr (fun p r => g (f p.1 p.2) r) i := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWith_foldl_eq_zip_foldl {f : α β γ} (i : δ):
(zipWith f l₁ l₂).foldl g i = (zip l₁ l₂).foldl (fun r p => g r (f p.1 p.2)) i := by
induction l₁ generalizing i l₂ <;> cases l₂ <;> simp_all
@[simp]
theorem zipWith_eq_nil_iff {f : α β γ} {l l'} : zipWith f l l' = [] l = [] l' = [] := by
cases l <;> cases l' <;> simp
theorem map_zipWith {δ : Type _} (f : α β) (g : γ δ α) (l : List γ) (l' : List δ) :
map f (zipWith g l l') = zipWith (fun x y => f (g x y)) l l' := by
induction l generalizing l' with
| nil => simp
| cons hd tl hl =>
· cases l'
· simp
· simp [hl]
theorem take_zipWith : (zipWith f l l').take n = zipWith f (l.take n) (l'.take n) := by
induction l generalizing l' n with
| nil => simp
| cons hd tl hl =>
cases l'
· simp
· cases n
· simp
· simp [hl]
@[deprecated take_zipWith (since := "2024-07-26")] abbrev zipWith_distrib_take := @take_zipWith
theorem drop_zipWith : (zipWith f l l').drop n = zipWith f (l.drop n) (l'.drop n) := by
induction l generalizing l' n with
| nil => simp
| cons hd tl hl =>
· cases l'
· simp
· cases n
· simp
· simp [hl]
@[deprecated drop_zipWith (since := "2024-07-26")] abbrev zipWith_distrib_drop := @drop_zipWith
theorem tail_zipWith : (zipWith f l l').tail = zipWith f l.tail l'.tail := by
rw [ drop_one]; simp [drop_zipWith]
@[deprecated tail_zipWith (since := "2024-07-28")] abbrev zipWith_distrib_tail := @tail_zipWith
theorem zipWith_append (f : α β γ) (l la : List α) (l' lb : List β)
(h : l.length = l'.length) :
zipWith f (l ++ la) (l' ++ lb) = zipWith f l l' ++ zipWith f la lb := by
induction l generalizing l' with
| nil =>
have : l' = [] := eq_nil_of_length_eq_zero (by simpa using h.symm)
simp [this]
| cons hl tl ih =>
cases l' with
| nil => simp at h
| cons head tail =>
simp only [length_cons, Nat.succ.injEq] at h
simp [ih _ h]
/-- See also `List.zipWith_replicate` in `Init.Data.List.TakeDrop` for a generalization with different lengths. -/
@[simp] theorem zipWith_replicate' {a : α} {b : β} {n : Nat} :
zipWith f (replicate n a) (replicate n b) = replicate n (f a b) := by
induction n with
| zero => rfl
| succ n ih => simp [replicate_succ, ih]
/-! ### zipWithAll -/
theorem getElem?_zipWithAll {f : Option α Option β γ} {i : Nat} :
(zipWithAll f as bs)[i]? = match as[i]?, bs[i]? with
| none, none => .none | a?, b? => some (f a? b?) := by
induction as generalizing bs i with
| nil => induction bs generalizing i with
| nil => simp
| cons b bs bih => cases i <;> simp_all
| cons a as aih => cases bs with
| nil =>
specialize @aih []
cases i <;> simp_all
| cons b bs => cases i <;> simp_all
@[deprecated getElem?_zipWithAll (since := "2024-06-12")]
theorem get?_zipWithAll {f : Option α Option β γ} :
(zipWithAll f as bs).get? i = match as.get? i, bs.get? i with
| none, none => .none | a?, b? => some (f a? b?) := by
simp [getElem?_zipWithAll]
set_option linter.deprecated false in
@[deprecated getElem?_zipWithAll (since := "2024-06-07")] abbrev zipWithAll_get? := @get?_zipWithAll
theorem head?_zipWithAll {f : Option α Option β γ} :
(zipWithAll f as bs).head? = match as.head?, bs.head? with
| none, none => .none | a?, b? => some (f a? b?) := by
simp [head?_eq_getElem?, getElem?_zipWithAll]
theorem head_zipWithAll {f : Option α Option β γ} (h) :
(zipWithAll f as bs).head h = f as.head? bs.head? := by
apply Option.some.inj
rw [ head?_eq_head, head?_zipWithAll]
split <;> simp_all
theorem zipWithAll_map {μ} (f : Option γ Option δ μ) (g : α γ) (h : β δ) (l₁ : List α) (l₂ : List β) :
zipWithAll f (l₁.map g) (l₂.map h) = zipWithAll (fun a b => f (g <$> a) (h <$> b)) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWithAll_map_left (l₁ : List α) (l₂ : List β) (f : α α') (g : Option α' Option β γ) :
zipWithAll g (l₁.map f) l₂ = zipWithAll (fun a b => g (f <$> a) b) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem zipWithAll_map_right (l₁ : List α) (l₂ : List β) (f : β β') (g : Option α Option β' γ) :
zipWithAll g l₁ (l₂.map f) = zipWithAll (fun a b => g a (f <$> b)) l₁ l₂ := by
induction l₁ generalizing l₂ <;> cases l₂ <;> simp_all
theorem map_zipWithAll {δ : Type _} (f : α β) (g : Option γ Option δ α) (l : List γ) (l' : List δ) :
map f (zipWithAll g l l') = zipWithAll (fun x y => f (g x y)) l l' := by
induction l generalizing l' with
| nil => simp
| cons hd tl hl =>
cases l' <;> simp_all
@[simp] theorem zipWithAll_replicate {a : α} {b : β} {n : Nat} :
zipWithAll f (replicate n a) (replicate n b) = replicate n (f a b) := by
induction n with
| zero => rfl
| succ n ih => simp [replicate_succ, ih]
/-! ### unzip -/
@[simp] theorem unzip_fst : (unzip l).fst = l.map Prod.fst := by
induction l <;> simp_all
@[simp] theorem unzip_snd : (unzip l).snd = l.map Prod.snd := by
induction l <;> simp_all
@[deprecated unzip_fst (since := "2024-07-28")] abbrev unzip_left := @unzip_fst
@[deprecated unzip_snd (since := "2024-07-28")] abbrev unzip_right := @unzip_snd
theorem unzip_eq_map : l : List (α × β), unzip l = (l.map Prod.fst, l.map Prod.snd)
| [] => rfl
| (a, b) :: l => by simp only [unzip_cons, map_cons, unzip_eq_map l]
theorem zip_unzip : l : List (α × β), zip (unzip l).1 (unzip l).2 = l
| [] => rfl
| (a, b) :: l => by simp only [unzip_cons, zip_cons_cons, zip_unzip l]
theorem unzip_zip_left :
{l₁ : List α} {l₂ : List β}, length l₁ length l₂ (unzip (zip l₁ l₂)).1 = l₁
| [], l₂, _ => rfl
| l₁, [], h => by rw [eq_nil_of_length_eq_zero (Nat.eq_zero_of_le_zero h)]; rfl
| a :: l₁, b :: l₂, h => by
simp only [zip_cons_cons, unzip_cons, unzip_zip_left (le_of_succ_le_succ h)]
theorem unzip_zip_right :
{l₁ : List α} {l₂ : List β}, length l₂ length l₁ (unzip (zip l₁ l₂)).2 = l₂
| [], l₂, _ => by simp_all
| l₁, [], _ => by simp
| a :: l₁, b :: l₂, h => by
simp only [zip_cons_cons, unzip_cons, unzip_zip_right (le_of_succ_le_succ h)]
theorem unzip_zip {l₁ : List α} {l₂ : List β} (h : length l₁ = length l₂) :
unzip (zip l₁ l₂) = (l₁, l₂) := by
ext
· rw [unzip_zip_left (Nat.le_of_eq h)]
· rw [unzip_zip_right (Nat.le_of_eq h.symm)]
theorem zip_of_prod {l : List α} {l' : List β} {lp : List (α × β)} (hl : lp.map Prod.fst = l)
(hr : lp.map Prod.snd = l') : lp = l.zip l' := by
rw [ hl, hr, zip_unzip lp, unzip_fst, unzip_snd, zip_unzip, zip_unzip]
@[simp] theorem unzip_replicate {n : Nat} {a : α} {b : β} :
unzip (replicate n (a, b)) = (replicate n a, replicate n b) := by
ext1 <;> simp

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@@ -102,6 +102,13 @@ def blt (a b : Nat) : Bool :=
attribute [simp] Nat.zero_le
attribute [simp] Nat.not_lt_zero
theorem and_forall_add_one {p : Nat Prop} : p 0 ( n, p (n + 1)) n, p n :=
fun h n => Nat.casesOn n h.1 h.2, fun h => h _, fun _ => h _
theorem or_exists_add_one : p 0 (Exists fun n => p (n + 1)) Exists p :=
fun h => h.elim (fun h0 => 0, h0) fun n, hn => n + 1, hn,
fun n, h => match n with | 0 => Or.inl h | n+1 => Or.inr n, h
/-! # Helper "packing" theorems -/
@[simp] theorem zero_eq : Nat.zero = 0 := rfl

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@@ -20,7 +20,12 @@ and later these lemmas should be organised into other files more systematically.
namespace Nat
attribute [simp] not_lt_zero
@[deprecated and_forall_add_one (since := "2024-07-30")] abbrev and_forall_succ := @and_forall_add_one
@[deprecated or_exists_add_one (since := "2024-07-30")] abbrev or_exists_succ := @or_exists_add_one
@[simp] theorem exists_ne_zero {P : Nat Prop} : ( n, ¬ n = 0 P n) n, P (n + 1) :=
fun n, h, w => by cases n with | zero => simp at h | succ n => exact n, w,
fun n, w => n + 1, by simp, w
/-! ## add -/

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@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
Authors: Scott Morrison
-/
prelude
import Init.Data.List.Lemmas
import Init.Data.List.Zip
import Init.Data.Int.DivModLemmas
import Init.Data.Nat.Gcd

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@@ -202,6 +202,17 @@ theorem exists_imp : ((∃ x, p x) → b) ↔ ∀ x, p x → b := forall_exists_
@[simp] theorem exists_const (α) [i : Nonempty α] : ( _ : α, b) b :=
fun _, h => h, i.elim Exists.intro
@[congr]
theorem exists_prop_congr {p p' : Prop} {q q' : p Prop} (hq : h, q h q' h) (hp : p p') :
Exists q h : p', q' (hp.2 h) :=
fun _, _ hp.1 _, (hq _).1 _, fun _, _ _, (hq _).2 _
theorem exists_prop_of_true {p : Prop} {q : p Prop} (h : p) : (Exists fun h' : p => q h') q h :=
@exists_const (q h) p h
@[simp] theorem exists_true_left (p : True Prop) : Exists p p True.intro :=
exists_prop_of_true _
section forall_congr
theorem forall_congr' (h : a, p a q a) : ( a, p a) a, q a :=

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@@ -109,4 +109,4 @@ A more restrictive but efficient max sharing primitive.
Remark: it optimizes the number of RC operations, and the strategy for caching results.
-/
@[extern "lean_sharecommon_quick"]
def ShareCommon.shareCommon' (a : α) : α := a
def ShareCommon.shareCommon' (a : @& α) : α := a

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@@ -31,7 +31,16 @@ register_builtin_option maxHeartbeats : Nat := {
descr := "maximum amount of heartbeats per command. A heartbeat is number of (small) memory allocations (in thousands), 0 means no limit"
}
def useDiagnosticMsg := s!"use `set_option {diagnostics.name} true` to get diagnostic information"
/--
If the `diagnostics` option is not already set, gives a message explaining this option.
Begins with a `\n`, so an error message can look like `m!"some error occurred{useDiagnosticMsg}"`.
-/
def useDiagnosticMsg : MessageData :=
MessageData.lazy fun ctx =>
if diagnostics.get ctx.opts then
pure ""
else
pure s!"\nAdditional diagnostic information may be available using the `set_option {diagnostics.name} true` command."
namespace Core
@@ -300,8 +309,10 @@ register_builtin_option debug.moduleNameAtTimeout : Bool := {
def throwMaxHeartbeat (moduleName : Name) (optionName : Name) (max : Nat) : CoreM Unit := do
let includeModuleName := debug.moduleNameAtTimeout.get ( getOptions)
let atModuleName := if includeModuleName then s!" at `{moduleName}`" else ""
let msg := s!"(deterministic) timeout{atModuleName}, maximum number of heartbeats ({max/1000}) has been reached\nuse `set_option {optionName} <num>` to set the limit\n{useDiagnosticMsg}"
throw <| Exception.error ( getRef) (MessageData.ofFormat (Std.Format.text msg))
throw <| Exception.error ( getRef) m!"\
(deterministic) timeout{atModuleName}, maximum number of heartbeats ({max/1000}) has been reached\n\
Use `set_option {optionName} <num>` to set the limit.\
{useDiagnosticMsg}"
def checkMaxHeartbeatsCore (moduleName : String) (optionName : Name) (max : Nat) : CoreM Unit := do
unless max == 0 do

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@@ -743,7 +743,7 @@ structure State where
abbrev M := ReaderT Context $ StateRefT State TermElabM
/-- Infer the `motive` using the expected type by `kabstract`ing the discriminants. -/
def mkMotive (discrs : Array Expr) (expectedType : Expr): MetaM Expr := do
def mkMotive (discrs : Array Expr) (expectedType : Expr) : MetaM Expr := do
discrs.foldrM (init := expectedType) fun discr motive => do
let discr instantiateMVars discr
let motiveBody kabstract motive discr
@@ -878,7 +878,16 @@ partial def main : M Expr := do
main
let idx := ( get).idx
if ( read).elimInfo.motivePos == idx then
let motive mkImplicitArg binderType binderInfo
let motive
match ( getNextArg? binderName binderInfo) with
| .some arg =>
/- Due to `Lean.Elab.Term.elabAppArgs.elabAsElim?`, this must be a positional argument that is the syntax `_`. -/
elabArg arg binderType
| .none | .undef =>
/- Note: undef occurs when the motive is explicit but missing.
In this case, we treat it as if it were an implicit argument
to support writing `h.rec` when `h : False`, rather than requiring `h.rec _`. -/
mkImplicitArg binderType binderInfo
setMotive motive
addArgAndContinue motive
else if let some tidx := ( read).elimInfo.targetsPos.indexOf? idx then
@@ -970,15 +979,34 @@ where
unless ( shouldElabAsElim declName) do return none
let elimInfo getElimInfo declName
forallTelescopeReducing ( inferType f) fun xs _ => do
if h : elimInfo.motivePos < xs.size then
let x := xs[elimInfo.motivePos]
/- Process arguments similar to `Lean.Elab.Term.ElabElim.main` to see if the motive has been
provided, in which case we use the standard app elaborator.
If the motive is explicit (like for `False.rec`), then a positional `_` counts as "not provided". -/
let mut args := args.toList
let mut namedArgs := namedArgs.toList
for x in xs[0:elimInfo.motivePos] do
let localDecl x.fvarId!.getDecl
if findBinderName? namedArgs.toList localDecl.userName matches some _ then
match findBinderName? namedArgs localDecl.userName with
| some _ => namedArgs := eraseNamedArg namedArgs localDecl.userName
| none => if localDecl.binderInfo.isExplicit then args := args.tailD []
-- Invariant: `elimInfo.motivePos < xs.size` due to construction of `elimInfo`.
let some x := xs[elimInfo.motivePos]? | unreachable!
let localDecl x.fvarId!.getDecl
if findBinderName? namedArgs localDecl.userName matches some _ then
-- motive has been explicitly provided, so we should use standard app elaborator
return none
else
match localDecl.binderInfo.isExplicit, args with
| true, .expr _ :: _ =>
-- motive has been explicitly provided, so we should use standard app elaborator
return none
return some elimInfo
else
return none
| true, .stx arg :: _ =>
if arg.isOfKind ``Lean.Parser.Term.hole then
return some elimInfo
else
-- positional motive is not `_`, so we should use standard app elaborator
return none
| _, _ => return some elimInfo
/--
Collect extra argument positions that must be elaborated eagerly when using `elab_as_elim`.

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@@ -42,7 +42,7 @@ def mkCalcTrans (result resultType step stepType : Expr) : MetaM (Expr × Expr)
unless ( getCalcRelation? resultType).isSome do
throwError "invalid 'calc' step, step result is not a relation{indentExpr resultType}"
return (result, resultType)
| _ => throwError "invalid 'calc' step, failed to synthesize `Trans` instance{indentExpr selfType}\n{useDiagnosticMsg}"
| _ => throwError "invalid 'calc' step, failed to synthesize `Trans` instance{indentExpr selfType}{useDiagnosticMsg}"
/--
Adds a type annotation to a hole that occurs immediately at the beginning of the term.

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@@ -91,8 +91,14 @@ def mkAuxFunction (ctx : Context) (auxFunName : Name) (indVal : InductiveVal): T
let header mkDecEqHeader indVal
let body mkMatch ctx header indVal
let binders := header.binders
let type `(Decidable ($(mkIdent header.targetNames[0]!) = $(mkIdent header.targetNames[1]!)))
`(private def $(mkIdent auxFunName):ident $binders:bracketedBinder* : $type:term := $body:term)
let target₁ := mkIdent header.targetNames[0]!
let target₂ := mkIdent header.targetNames[1]!
let termSuffix if indVal.isRec
then `(Parser.Termination.suffix|termination_by structural $target₁)
else `(Parser.Termination.suffix|)
let type `(Decidable ($target₁ = $target₂))
`(private def $(mkIdent auxFunName):ident $binders:bracketedBinder* : $type:term := $body:term
$termSuffix:suffix)
def mkAuxFunctions (ctx : Context) : TermElabM (TSyntax `command) := do
let mut res : Array (TSyntax `command) := #[]

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@@ -39,7 +39,7 @@ def parseImports (input : String) (fileName : Option String := none) : IO (Array
def printImports (input : String) (fileName : Option String) : IO Unit := do
let (deps, _, _) parseImports input fileName
for dep in deps do
let fname findOLean dep.module
let fname findOLean (checkExists := false) dep.module
IO.println fname
end Lean.Elab

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@@ -6,7 +6,7 @@ Authors: Scott Morrison
prelude
import Init.BinderPredicates
import Init.Data.Int.Order
import Init.Data.List.Lemmas
import Init.Data.List.MinMax
import Init.Data.Nat.MinMax
import Init.Data.Option.Lemmas

View File

@@ -996,7 +996,7 @@ def synthesizeInstMVarCore (instMVar : MVarId) (maxResultSize? : Option Nat := n
if ( read).ignoreTCFailures then
return false
else
throwError "failed to synthesize{indentExpr type}{extraErrorMsg}\n{useDiagnosticMsg}"
throwError "failed to synthesize{indentExpr type}{extraErrorMsg}{useDiagnosticMsg}"
def mkCoe (expectedType : Expr) (e : Expr) (f? : Option Expr := none) (errorMsgHeader? : Option String := none) : TermElabM Expr := do
withTraceNode `Elab.coe (fun _ => return m!"adding coercion for {e} : {← inferType e} =?= {expectedType}") do

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@@ -806,8 +806,6 @@ partial def importModulesCore (imports : Array Import) : ImportStateM Unit := do
continue
modify fun s => { s with moduleNameSet := s.moduleNameSet.insert i.module }
let mFile findOLean i.module
unless ( mFile.pathExists) do
throw <| IO.userError s!"object file '{mFile}' of module {i.module} does not exist"
let (mod, region) readModuleData mFile
importModulesCore mod.imports
modify fun s => { s with

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@@ -10,8 +10,8 @@ Authors: Sebastian Ullrich
prelude
import Lean.Language.Basic
import Lean.Language.Lean.Types
import Lean.Parser.Module
import Lean.Elab.Command
import Lean.Elab.Import
/-!
@@ -166,11 +166,6 @@ namespace Lean.Language.Lean
open Lean.Elab Command
open Lean.Parser
private def pushOpt (a? : Option α) (as : Array α) : Array α :=
match a? with
| some a => as.push a
| none => as
/-- Option for capturing output to stderr during elaboration. -/
register_builtin_option stderrAsMessages : Bool := {
defValue := true
@@ -178,101 +173,6 @@ register_builtin_option stderrAsMessages : Bool := {
descr := "(server) capture output to the Lean stderr channel (such as from `dbg_trace`) during elaboration of a command as a diagnostic message"
}
/-! The hierarchy of Lean snapshot types -/
/-- Snapshot after elaboration of the entire command. -/
structure CommandFinishedSnapshot extends Language.Snapshot where
/-- Resulting elaboration state. -/
cmdState : Command.State
deriving Nonempty
instance : ToSnapshotTree CommandFinishedSnapshot where
toSnapshotTree s := s.toSnapshot, #[]
/-- State after a command has been parsed. -/
structure CommandParsedSnapshotData extends Snapshot where
/-- Syntax tree of the command. -/
stx : Syntax
/-- Resulting parser state. -/
parserState : Parser.ModuleParserState
/--
Snapshot for incremental reporting and reuse during elaboration, type dependent on specific
elaborator.
-/
elabSnap : SnapshotTask DynamicSnapshot
/-- State after processing is finished. -/
finishedSnap : SnapshotTask CommandFinishedSnapshot
/-- Cache for `save`; to be replaced with incrementality. -/
tacticCache : IO.Ref Tactic.Cache
deriving Nonempty
/-- State after a command has been parsed. -/
-- workaround for lack of recursive structures
inductive CommandParsedSnapshot where
/-- Creates a command parsed snapshot. -/
| mk (data : CommandParsedSnapshotData)
(nextCmdSnap? : Option (SnapshotTask CommandParsedSnapshot))
deriving Nonempty
/-- The snapshot data. -/
abbrev CommandParsedSnapshot.data : CommandParsedSnapshot CommandParsedSnapshotData
| mk data _ => data
/-- Next command, unless this is a terminal command. -/
abbrev CommandParsedSnapshot.nextCmdSnap? : CommandParsedSnapshot
Option (SnapshotTask CommandParsedSnapshot)
| mk _ next? => next?
partial instance : ToSnapshotTree CommandParsedSnapshot where
toSnapshotTree := go where
go s := s.data.toSnapshot,
#[s.data.elabSnap.map (sync := true) toSnapshotTree,
s.data.finishedSnap.map (sync := true) toSnapshotTree] |>
pushOpt (s.nextCmdSnap?.map (·.map (sync := true) go))
/-- State after successful importing. -/
structure HeaderProcessedState where
/-- The resulting initial elaboration state. -/
cmdState : Command.State
/-- First command task (there is always at least a terminal command). -/
firstCmdSnap : SnapshotTask CommandParsedSnapshot
/-- State after the module header has been processed including imports. -/
structure HeaderProcessedSnapshot extends Snapshot where
/-- State after successful importing. -/
result? : Option HeaderProcessedState
isFatal := result?.isNone
instance : ToSnapshotTree HeaderProcessedSnapshot where
toSnapshotTree s := s.toSnapshot, #[] |>
pushOpt (s.result?.map (·.firstCmdSnap.map (sync := true) toSnapshotTree))
/-- State after successfully parsing the module header. -/
structure HeaderParsedState where
/-- Resulting parser state. -/
parserState : Parser.ModuleParserState
/-- Header processing task. -/
processedSnap : SnapshotTask HeaderProcessedSnapshot
/-- State after the module header has been parsed. -/
structure HeaderParsedSnapshot extends Snapshot where
/-- Parser input context supplied by the driver, stored here for incremental parsing. -/
ictx : Parser.InputContext
/-- Resulting syntax tree. -/
stx : Syntax
/-- State after successful parsing. -/
result? : Option HeaderParsedState
isFatal := result?.isNone
/-- Cancellation token for interrupting processing of this run. -/
cancelTk? : Option IO.CancelToken
instance : ToSnapshotTree HeaderParsedSnapshot where
toSnapshotTree s := s.toSnapshot,
#[] |> pushOpt (s.result?.map (·.processedSnap.map (sync := true) toSnapshotTree))
/-- Shortcut accessor to the final header state, if successful. -/
def HeaderParsedSnapshot.processedResult (snap : HeaderParsedSnapshot) :
SnapshotTask (Option HeaderProcessedState) :=
snap.result?.bind (·.processedSnap.map (sync := true) (·.result?)) |>.getD (.pure none)
/-- Initial snapshot of the Lean language processor: a "header parsed" snapshot. -/
abbrev InitialSnapshot := HeaderParsedSnapshot
/-- Lean-specific processing context. -/
structure LeanProcessingContext extends ProcessingContext where
/-- Position of the first file difference if there was a previous invocation. -/

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@@ -0,0 +1,119 @@
/-
Copyright (c) 2023 Lean FRO. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Implementation of the Lean language: parsing and processing of header and commands, incremental
recompilation
Authors: Sebastian Ullrich
-/
prelude
import Lean.Language.Basic
import Lean.Elab.Command
set_option linter.missingDocs true
namespace Lean.Language.Lean
open Lean.Elab Command
open Lean.Parser
private def pushOpt (a? : Option α) (as : Array α) : Array α :=
match a? with
| some a => as.push a
| none => as
/-! The hierarchy of Lean snapshot types -/
/-- Snapshot after elaboration of the entire command. -/
structure CommandFinishedSnapshot extends Language.Snapshot where
/-- Resulting elaboration state. -/
cmdState : Command.State
deriving Nonempty
instance : ToSnapshotTree CommandFinishedSnapshot where
toSnapshotTree s := s.toSnapshot, #[]
/-- State after a command has been parsed. -/
structure CommandParsedSnapshotData extends Snapshot where
/-- Syntax tree of the command. -/
stx : Syntax
/-- Resulting parser state. -/
parserState : Parser.ModuleParserState
/--
Snapshot for incremental reporting and reuse during elaboration, type dependent on specific
elaborator.
-/
elabSnap : SnapshotTask DynamicSnapshot
/-- State after processing is finished. -/
finishedSnap : SnapshotTask CommandFinishedSnapshot
/-- Cache for `save`; to be replaced with incrementality. -/
tacticCache : IO.Ref Tactic.Cache
deriving Nonempty
/-- State after a command has been parsed. -/
-- workaround for lack of recursive structures
inductive CommandParsedSnapshot where
/-- Creates a command parsed snapshot. -/
| mk (data : CommandParsedSnapshotData)
(nextCmdSnap? : Option (SnapshotTask CommandParsedSnapshot))
deriving Nonempty
/-- The snapshot data. -/
abbrev CommandParsedSnapshot.data : CommandParsedSnapshot CommandParsedSnapshotData
| mk data _ => data
/-- Next command, unless this is a terminal command. -/
abbrev CommandParsedSnapshot.nextCmdSnap? : CommandParsedSnapshot
Option (SnapshotTask CommandParsedSnapshot)
| mk _ next? => next?
partial instance : ToSnapshotTree CommandParsedSnapshot where
toSnapshotTree := go where
go s := s.data.toSnapshot,
#[s.data.elabSnap.map (sync := true) toSnapshotTree,
s.data.finishedSnap.map (sync := true) toSnapshotTree] |>
pushOpt (s.nextCmdSnap?.map (·.map (sync := true) go))
/-- State after successful importing. -/
structure HeaderProcessedState where
/-- The resulting initial elaboration state. -/
cmdState : Command.State
/-- First command task (there is always at least a terminal command). -/
firstCmdSnap : SnapshotTask CommandParsedSnapshot
/-- State after the module header has been processed including imports. -/
structure HeaderProcessedSnapshot extends Snapshot where
/-- State after successful importing. -/
result? : Option HeaderProcessedState
isFatal := result?.isNone
instance : ToSnapshotTree HeaderProcessedSnapshot where
toSnapshotTree s := s.toSnapshot, #[] |>
pushOpt (s.result?.map (·.firstCmdSnap.map (sync := true) toSnapshotTree))
/-- State after successfully parsing the module header. -/
structure HeaderParsedState where
/-- Resulting parser state. -/
parserState : Parser.ModuleParserState
/-- Header processing task. -/
processedSnap : SnapshotTask HeaderProcessedSnapshot
/-- State after the module header has been parsed. -/
structure HeaderParsedSnapshot extends Snapshot where
/-- Parser input context supplied by the driver, stored here for incremental parsing. -/
ictx : Parser.InputContext
/-- Resulting syntax tree. -/
stx : Syntax
/-- State after successful parsing. -/
result? : Option HeaderParsedState
isFatal := result?.isNone
/-- Cancellation token for interrupting processing of this run. -/
cancelTk? : Option IO.CancelToken
instance : ToSnapshotTree HeaderParsedSnapshot where
toSnapshotTree s := s.toSnapshot,
#[] |> pushOpt (s.result?.map (·.processedSnap.map (sync := true) toSnapshotTree))
/-- Shortcut accessor to the final header state, if successful. -/
def HeaderParsedSnapshot.processedResult (snap : HeaderParsedSnapshot) :
SnapshotTask (Option HeaderProcessedState) :=
snap.result?.bind (·.processedSnap.map (sync := true) (·.result?)) |>.getD (.pure none)
/-- Initial snapshot of the Lean language processor: a "header parsed" snapshot. -/
abbrev InitialSnapshot := HeaderParsedSnapshot

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@@ -636,7 +636,7 @@ def main (type : Expr) (maxResultSize : Nat) : MetaM (Option AbstractMVarsResult
(action.run { maxResultSize := maxResultSize, maxHeartbeats := getMaxHeartbeats ( getOptions) } |>.run' {})
fun ex =>
if ex.isRuntime then
throwError "failed to synthesize{indentExpr type}\n{ex.toMessageData}\n{useDiagnosticMsg}"
throwError "failed to synthesize{indentExpr type}\n{ex.toMessageData}{useDiagnosticMsg}"
else
throw ex
@@ -810,7 +810,7 @@ def trySynthInstance (type : Expr) (maxResultSize? : Option Nat := none) : MetaM
(fun _ => pure LOption.undef)
def throwFailedToSynthesize (type : Expr) : MetaM Expr :=
throwError "failed to synthesize{indentExpr type}\n{useDiagnosticMsg}"
throwError "failed to synthesize{indentExpr type}{useDiagnosticMsg}"
def synthInstance (type : Expr) (maxResultSize? : Option Nat := none) : MetaM Expr :=
catchInternalId isDefEqStuckExceptionId

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@@ -60,6 +60,16 @@ builtin_dsimproc [simp, seval] reducePow ((_ ^ _ : Nat)) := fun e => do
unless ( checkExponent m) do return .continue
return .done <| toExpr (n ^ m)
builtin_dsimproc [simp, seval] reduceAnd ((_ &&& _ : Nat)) := reduceBin ``HOr.hOr 6 (· &&& ·)
builtin_dsimproc [simp, seval] reduceXor ((_ ^^^ _ : Nat)) := reduceBin ``HXor.hXor 6 (· ^^^ ·)
builtin_dsimproc [simp, seval] reduceOr ((_ ||| _ : Nat)) := reduceBin ``HOr.hOr 6 (· ||| ·)
builtin_dsimproc [simp, seval] reduceShiftLeft ((_ <<< _ : Nat)) :=
reduceBin ``HShiftLeft.hShiftLeft 6 (· <<< ·)
builtin_dsimproc [simp, seval] reduceShiftRight ((_ >>> _ : Nat)) :=
reduceBin ``HShiftRight.hShiftRight 6 (· >>> ·)
builtin_dsimproc [simp, seval] reduceGcd (gcd _ _) := reduceBin ``gcd 2 gcd
builtin_simproc [simp, seval] reduceLT (( _ : Nat) < _) := reduceBinPred ``LT.lt 4 (. < .)

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@@ -703,6 +703,9 @@ list, so it should be brief.
@[builtin_command_parser] def genInjectiveTheorems := leading_parser
"gen_injective_theorems% " >> ident
/-- To be implemented. -/
@[builtin_command_parser] def «include» := leading_parser "include " >> many1 (checkColGt >> ident)
/-- No-op parser used as syntax kind for attaching remaining whitespace at the end of the input. -/
@[run_builtin_parser_attribute_hooks] def eoi : Parser := leading_parser ""

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@@ -339,19 +339,22 @@ inductive AppImplicitArg
| skip
/-- A regular argument. -/
| regular (s : Term)
/-- A regular argument that, if it comes as the last argument, may be omitted. -/
| optional (name : Name) (s : Term)
/-- It's a named argument. Named arguments inhibit applying unexpanders. -/
| named (s : TSyntax ``Parser.Term.namedArgument)
deriving Inhabited
/-- Whether unexpanding is allowed with this argument. -/
def AppImplicitArg.canUnexpand : AppImplicitArg Bool
| .regular .. | .skip => true
| .regular .. | .optional .. | .skip => true
| .named .. => false
/-- If the argument has associated syntax, returns it. -/
def AppImplicitArg.syntax? : AppImplicitArg Option Syntax
| .skip => none
| .regular s => s
| .optional _ s => s
| .named s => s
/--
@@ -371,13 +374,13 @@ def delabAppImplicitCore (unexpand : Bool) (numArgs : Nat) (delabHead : Delab) (
appFieldNotationCandidate?
else
pure none
let (fnStx, args)
let (fnStx, args')
withBoundedAppFnArgs numArgs
(do return (( delabHead), Array.mkEmpty numArgs))
(fun (fnStx, args) => do
let idx := args.size
let arg mkArg (numArgs - idx - 1) paramKinds[idx]!
return (fnStx, args.push arg))
(fun (fnStx, args) => return (fnStx, args.push ( mkArg paramKinds[args.size]!)))
-- Strip off optional arguments. We save the original `args'` for structure instance notation
let args := args'.popWhile (· matches .optional ..)
-- App unexpanders
if pure unexpand <&&> getPPOption getPPNotation then
@@ -385,11 +388,10 @@ def delabAppImplicitCore (unexpand : Bool) (numArgs : Nat) (delabHead : Delab) (
if let some stx (some <$> tryAppUnexpanders fnStx args) <|> pure none then
return stx
let stx := Syntax.mkApp fnStx (args.filterMap (·.syntax?))
-- Structure instance notation
if pure (unexpand && args.all (·.canUnexpand)) <&&> getPPOption getPPStructureInstances then
if pure (unexpand && args'.all (·.canUnexpand)) <&&> getPPOption getPPStructureInstances then
-- Try using the structure instance unexpander.
let stx := Syntax.mkApp fnStx (args'.filterMap (·.syntax?))
if let some stx (some <$> unexpandStructureInstance stx) <|> pure none then
return stx
@@ -416,7 +418,7 @@ def delabAppImplicitCore (unexpand : Bool) (numArgs : Nat) (delabHead : Delab) (
return Syntax.mkApp head (args'.filterMap (·.syntax?))
-- Normal application
return stx
return Syntax.mkApp fnStx (args.filterMap (·.syntax?))
where
mkNamedArg (name : Name) : DelabM AppImplicitArg :=
return .named <| `(Parser.Term.namedArgument| ($(mkIdent name) := $( delab)))
@@ -424,15 +426,16 @@ where
Delaborates the current argument.
The argument `remainingArgs` is the number of arguments in the application after this one.
-/
mkArg (remainingArgs : Nat) (param : ParamKind) : DelabM AppImplicitArg := do
mkArg (param : ParamKind) : DelabM AppImplicitArg := do
let arg getExpr
if getPPOption getPPAnalysisSkip then return .skip
else if getPPOption getPPAnalysisHole then return .regular ( `(_))
else if getPPOption getPPAnalysisNamedArg then
mkNamedArg param.name
else if param.defVal.isSome && remainingArgs == 0 && param.defVal.get! == arg then
-- Assumption: `useAppExplicit` has already detected whether it is ok to omit this argument
return .skip
else if param.defVal.isSome && param.defVal.get! == arg then
-- Assumption: `useAppExplicit` has already detected whether it is ok to omit this argument, if it is the last one.
-- We will later remove all optional arguments from the end.
return .optional param.name ( delab)
else if param.bInfo.isExplicit then
return .regular ( delab)
else if pure (param.name == `motive) <&&> shouldShowMotive arg ( getOptions) then

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@@ -16,7 +16,7 @@ import Lean.Data.Json.FromToJson
import Lean.Util.FileSetupInfo
import Lean.LoadDynlib
import Lean.Language.Basic
import Lean.Language.Lean
import Lean.Server.Utils
import Lean.Server.AsyncList

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@@ -5,7 +5,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
Authors: Wojciech Nawrocki, Marc Huisinga
-/
prelude
import Lean.Language.Lean
import Lean.Language.Lean.Types
import Lean.Server.Utils
import Lean.Server.Snapshots
import Lean.Server.AsyncList

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@@ -9,7 +9,6 @@ import Init.System.IO
import Lean.Elab.Import
import Lean.Elab.Command
import Lean.Language.Lean
import Lean.Widget.InteractiveDiagnostic

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@@ -5,7 +5,6 @@ Authors: Leonardo de Moura
-/
prelude
import Lean.Expr
import Lean.Util.PtrSet
namespace Lean
namespace Expr

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@@ -11,52 +11,35 @@ namespace Lean
namespace Expr
namespace FoldConstsImpl
abbrev cacheSize : USize := 8192 - 1
unsafe structure State where
visited : PtrSet Expr := mkPtrSet
visitedConsts : NameHashSet := {}
structure State where
visitedTerms : Array Expr -- Remark: cache based on pointer address. Our "unsafe" implementation relies on the fact that `()` is not a valid Expr
visitedConsts : NameHashSet -- cache based on structural equality
unsafe abbrev FoldM := StateM State
abbrev FoldM := StateM State
unsafe def visited (e : Expr) (size : USize) : FoldM Bool := do
let s get
let h := ptrAddrUnsafe e
let i := h % size
let k := s.visitedTerms.uget i lcProof
if ptrAddrUnsafe k == h then pure true
else do
modify fun s => { s with visitedTerms := s.visitedTerms.uset i e lcProof }
pure false
unsafe def fold {α : Type} (f : Name α α) (size : USize) (e : Expr) (acc : α) : FoldM α :=
unsafe def fold {α : Type} (f : Name α α) (e : Expr) (acc : α) : FoldM α :=
let rec visit (e : Expr) (acc : α) : FoldM α := do
if ( visited e size) then
pure acc
else
match e with
| Expr.forallE _ d b _ => visit b ( visit d acc)
| Expr.lam _ d b _ => visit b ( visit d acc)
| Expr.mdata _ b => visit b acc
| Expr.letE _ t v b _ => visit b ( visit v ( visit t acc))
| Expr.app f a => visit a ( visit f acc)
| Expr.proj _ _ b => visit b acc
| Expr.const c _ =>
let s get
if s.visitedConsts.contains c then
pure acc
else do
modify fun s => { s with visitedConsts := s.visitedConsts.insert c };
pure $ f c acc
| _ => pure acc
if ( get).visited.contains e then
return acc
modify fun s => { s with visited := s.visited.insert e }
match e with
| .forallE _ d b _ => visit b ( visit d acc)
| .lam _ d b _ => visit b ( visit d acc)
| .mdata _ b => visit b acc
| .letE _ t v b _ => visit b ( visit v ( visit t acc))
| .app f a => visit a ( visit f acc)
| .proj _ _ b => visit b acc
| .const c _ =>
if ( get).visitedConsts.contains c then
return acc
else
modify fun s => { s with visitedConsts := s.visitedConsts.insert c };
return f c acc
| _ => return acc
visit e acc
unsafe def initCache : State :=
{ visitedTerms := mkArray cacheSize.toNat (cast lcProof ()),
visitedConsts := {} }
@[inline] unsafe def foldUnsafe {α : Type} (e : Expr) (init : α) (f : Name α α) : α :=
(fold f cacheSize e init).run' initCache
(fold f e init).run' {}
end FoldConstsImpl

View File

@@ -40,25 +40,52 @@ where
| Name.anonymous => base
| Name.num _ _ => panic! "ill-formed import"
variable (base : FilePath) (ext : String) in
/--
Checks whether a module of the given name and extension exists in `base`; this uses case-sensitive
path comparisons regardless of underlying file system to ensure the check is consistent across
platforms.
-/
partial def moduleExists : Name IO Bool := go ext
where go (ext : String)
| .mkStr parent str => do
-- Case-sensitive check for file with extension in top-level call, for directory recursively
let entryName := if ext.isEmpty then str else s!"{str}.{ext}"
unless ( go "" parent) do
return false
return ( (modToFilePath base parent "").readDir).any (·.fileName == entryName)
| .anonymous => base.pathExists
| .num .. => panic! "ill-formed import"
/-- A `.olean' search path. -/
abbrev SearchPath := System.SearchPath
namespace SearchPath
def findRoot (sp : SearchPath) (ext : String) (pkg : String) : IO (Option FilePath) := do
sp.findM? fun p => do
unless ( p.isDir) do -- Lake may pass search roots that do not exist (yet)
return false
if ( (p / pkg).isDir) then
return ( p.readDir).any (·.fileName == pkg)
else
let fileName := s!"{pkg}.{ext}"
return ( p.readDir).any (·.fileName == fileName)
/-- If the package of `mod` can be found in `sp`, return the path with extension
`ext` (`lean` or `olean`) corresponding to `mod`. Otherwise, return `none`. Does
not check whether the returned path exists. -/
def findWithExt (sp : SearchPath) (ext : String) (mod : Name) : IO (Option FilePath) := do
let pkg := mod.getRoot.toString (escape := false)
let root? sp.findM? fun p =>
(p / pkg).isDir <||> ((p / pkg).addExtension ext).pathExists
let root? findRoot sp ext pkg
return root?.map (modToFilePath · mod ext)
/-- Like `findWithExt`, but ensures the returned path exists. -/
def findModuleWithExt (sp : SearchPath) (ext : String) (mod : Name) : IO (Option FilePath) := do
if let some path findWithExt sp ext mod then
if path.pathExists then
return some path
let pkg := mod.getRoot.toString (escape := false)
if let some root findRoot sp ext pkg then
if ( moduleExists root ext mod) then
return some <| modToFilePath root mod ext
return none
def findAllWithExt (sp : SearchPath) (ext : String) : IO (Array FilePath) := do
@@ -105,12 +132,20 @@ def initSearchPath (leanSysroot : FilePath) (sp : SearchPath := ∅) : IO Unit :
private def initSearchPathInternal : IO Unit := do
initSearchPath ( getBuildDir)
partial def findOLean (mod : Name) : IO FilePath := do
/--
Returns the path of the .olean file for `mod`. Throws an error if no search path entry for `mod`
could be located, or if `checkExists` is true and the resulting path does not exist.
-/
partial def findOLean (mod : Name) (checkExists := true) : IO FilePath := do
let sp searchPathRef.get
if let some fname sp.findWithExt "olean" mod then
return fname
let pkg := mod.getRoot.toString (escape := false)
if let some root sp.findRoot "olean" pkg then
let path := modToFilePath root mod "olean"
if !checkExists || ( moduleExists root "olean" mod) then
return path
else
throw <| IO.userError s!"object file '{path}' of module {mod} does not exist"
else
let pkg := FilePath.mk <| mod.getRoot.toString (escape := false)
let mut msg := s!"unknown module prefix '{pkg}'
No directory '{pkg}' or file '{pkg}.olean' in the search path entries:

View File

@@ -9,6 +9,7 @@ Author: Leonardo de Moura
#include <limits>
#include "runtime/sstream.h"
#include "runtime/thread.h"
#include "runtime/sharecommon.h"
#include "util/map_foreach.h"
#include "util/io.h"
#include "kernel/environment.h"
@@ -220,12 +221,15 @@ environment environment::add_theorem(declaration const & d, bool check) const {
theorem_val const & v = d.to_theorem_val();
if (check) {
type_checker checker(*this, diag.get());
if (!checker.is_prop(v.get_type()))
throw theorem_type_is_not_prop(*this, v.get_name(), v.get_type());
sharecommon_persistent_fn share;
expr val(share(v.get_value().raw()));
expr type(share(v.get_type().raw()));
if (!checker.is_prop(type))
throw theorem_type_is_not_prop(*this, v.get_name(), type);
check_constant_val(*this, v.to_constant_val(), checker);
check_no_metavar_no_fvar(*this, v.get_name(), v.get_value());
expr val_type = checker.check(v.get_value(), v.get_lparams());
if (!checker.is_def_eq(val_type, v.get_type()))
check_no_metavar_no_fvar(*this, v.get_name(), val);
expr val_type = checker.check(val, v.get_lparams());
if (!checker.is_def_eq(val_type, type))
throw definition_type_mismatch_exception(*this, d, val_type);
}
return diag.update(add(constant_info(d)));

View File

@@ -11,65 +11,49 @@ Author: Leonardo de Moura
#include "kernel/expr.h"
#include "kernel/expr_sets.h"
#ifndef LEAN_EQ_CACHE_CAPACITY
#define LEAN_EQ_CACHE_CAPACITY 1024*8
#endif
namespace lean {
struct eq_cache {
struct entry {
object * m_a;
object * m_b;
entry():m_a(nullptr), m_b(nullptr) {}
};
unsigned m_capacity;
std::vector<entry> m_cache;
std::vector<unsigned> m_used;
eq_cache():m_capacity(LEAN_EQ_CACHE_CAPACITY), m_cache(LEAN_EQ_CACHE_CAPACITY) {}
/**
\brief Functional object for comparing expressions.
bool check(expr const & a, expr const & b) {
if (!is_shared(a) || !is_shared(b))
return false;
unsigned i = hash(hash(a), hash(b)) % m_capacity;
if (m_cache[i].m_a == a.raw() && m_cache[i].m_b == b.raw()) {
return true;
} else {
if (m_cache[i].m_a == nullptr)
m_used.push_back(i);
m_cache[i].m_a = a.raw();
m_cache[i].m_b = b.raw();
return false;
}
}
void clear() {
for (unsigned i : m_used)
m_cache[i].m_a = nullptr;
m_used.clear();
}
};
/* CACHE_RESET: No */
MK_THREAD_LOCAL_GET_DEF(eq_cache, get_eq_cache);
/** \brief Functional object for comparing expressions.
Remark if CompareBinderInfo is true, then functional object will also compare
binder information attached to lambda and Pi expressions */
Remark if CompareBinderInfo is true, then functional object will also compare
binder information attached to lambda and Pi expressions
*/
template<bool CompareBinderInfo>
class expr_eq_fn {
eq_cache & m_cache;
struct key_hasher {
std::size_t operator()(std::pair<lean_object *, lean_object *> const & p) const {
return hash((size_t)p.first >> 3, (size_t)p.first >> 3);
}
};
typedef std::unordered_set<std::pair<lean_object *, lean_object *>, key_hasher> cache;
cache * m_cache = nullptr;
bool check_cache(expr const & a, expr const & b) {
if (!is_shared(a) || !is_shared(b))
return false;
if (!m_cache)
m_cache = new cache();
std::pair<lean_object *, lean_object *> key(a.raw(), b.raw());
if (m_cache->find(key) != m_cache->end())
return true;
m_cache->insert(key);
return false;
}
static void check_system() {
::lean::check_system("expression equality test");
}
bool apply(expr const & a, expr const & b) {
bool apply(expr const & a, expr const & b, bool root = false) {
if (is_eqp(a, b)) return true;
if (hash(a) != hash(b)) return false;
if (a.kind() != b.kind()) return false;
if (is_bvar(a)) return bvar_idx(a) == bvar_idx(b);
if (m_cache.check(a, b))
switch (a.kind()) {
case expr_kind::BVar: return bvar_idx(a) == bvar_idx(b);
case expr_kind::Lit: return lit_value(a) == lit_value(b);
case expr_kind::MVar: return mvar_name(a) == mvar_name(b);
case expr_kind::FVar: return fvar_name(a) == fvar_name(b);
case expr_kind::Sort: return sort_level(a) == sort_level(b);
default: break;
}
if (!root && check_cache(a, b))
return true;
/*
We increase the number of heartbeats here because some code (e.g., `simp`) may spend a lot of time comparing
@@ -78,6 +62,10 @@ class expr_eq_fn {
lean_inc_heartbeat();
switch (a.kind()) {
case expr_kind::BVar:
case expr_kind::Lit:
case expr_kind::MVar:
case expr_kind::FVar:
case expr_kind::Sort:
lean_unreachable(); // LCOV_EXCL_LINE
case expr_kind::MData:
return
@@ -88,16 +76,10 @@ class expr_eq_fn {
apply(proj_expr(a), proj_expr(b)) &&
proj_sname(a) == proj_sname(b) &&
proj_idx(a) == proj_idx(b);
case expr_kind::Lit:
return lit_value(a) == lit_value(b);
case expr_kind::Const:
return
const_name(a) == const_name(b) &&
compare(const_levels(a), const_levels(b), [](level const & l1, level const & l2) { return l1 == l2; });
case expr_kind::MVar:
return mvar_name(a) == mvar_name(b);
case expr_kind::FVar:
return fvar_name(a) == fvar_name(b);
case expr_kind::App:
check_system();
return
@@ -117,15 +99,13 @@ class expr_eq_fn {
apply(let_value(a), let_value(b)) &&
apply(let_body(a), let_body(b)) &&
(!CompareBinderInfo || let_name(a) == let_name(b));
case expr_kind::Sort:
return sort_level(a) == sort_level(b);
}
lean_unreachable(); // LCOV_EXCL_LINE
}
public:
expr_eq_fn():m_cache(get_eq_cache()) {}
~expr_eq_fn() { m_cache.clear(); }
bool operator()(expr const & a, expr const & b) { return apply(a, b); }
expr_eq_fn() {}
~expr_eq_fn() { if (m_cache) delete m_cache; }
bool operator()(expr const & a, expr const & b) { return apply(a, b, true); }
};
bool is_equal(expr const & a, expr const & b) {

View File

@@ -14,7 +14,7 @@ namespace lean {
class replace_rec_fn {
struct key_hasher {
std::size_t operator()(std::pair<lean_object *, unsigned> const & p) const {
return hash((size_t)p.first, p.second);
return hash((size_t)p.first >> 3, p.second);
}
};
std::unordered_map<std::pair<lean_object *, unsigned>, expr, key_hasher> m_cache;

View File

@@ -31,6 +31,9 @@ Recursively parse the Lean files of a module and its imports
building an `Array` product of its direct local imports.
-/
def Module.recParseImports (mod : Module) : FetchM (Array Module) := do
-- Make sure we fail reading the file independently of the FS case sensitivity
unless ( Lean.moduleExists mod.lib.srcDir "lean" mod.name) do
error s!"module source file not found: {mod.leanFile}"
let contents IO.FS.readFile mod.leanFile
let imports Lean.parseImports' contents mod.leanFile.toString
let mods imports.foldlM (init := OrdModuleSet.empty) fun set imp =>

View File

@@ -4,11 +4,8 @@ Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <vector>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include "runtime/object.h"
#include "runtime/sharecommon.h"
#include "runtime/hash.h"
namespace lean {
@@ -271,176 +268,168 @@ extern "C" LEAN_EXPORT obj_res lean_state_sharecommon(b_obj_arg tc, obj_arg s, o
return sharecommon_fn(tc, s)(a);
}
/*
A faster version of `sharecommon_fn` which only uses a local state.
It optimizes the number of RC operations, the strategy for caching results,
and uses C++ hashmap.
We do not increment reference counters when inserting Lean objects at `m_cache` and `m_set`.
This is correct because
- The domain of `m_cache` contains only sub-objects of `lean_sharecommon_quick` parameter,
and we know the object referenced by this parameter will remain alive.
- The range of `m_cache` contains only new objects that have been maxed shared, and these
objects will be are sub-objects of the object returned by `lean_sharecommon_quick`.
- `m_set` is like the range of `m_cache`.
*/
class sharecommon_quick_fn {
struct set_hash {
std::size_t operator()(lean_object * o) const { return lean_sharecommon_hash(o); }
};
struct set_eq {
std::size_t operator()(lean_object * o1, lean_object * o2) const { return lean_sharecommon_eq(o1, o2); }
};
/*
We use `m_cache` to ensure we do **not** traverse a DAG as a tree.
We use pointer equality for this collection.
*/
std::unordered_map<lean_object *, lean_object *> m_cache;
/* Set of maximally shared terms. AKA hash-consing table. */
std::unordered_set<lean_object *, set_hash, set_eq> m_set;
/*
We do not increment reference counters when inserting Lean objects at `m_cache` and `m_set`.
This is correct because
- The domain of `m_cache` contains only sub-objects of `lean_sharecommon_quick` parameter,
and we know the object referenced by this parameter will remain alive.
- The range of `m_cache` contains only new objects that have been maxed shared, and these
objects will be are sub-objects of the object returned by `lean_sharecommon_quick`.
- `m_set` is like the range of `m_cache`.
*/
lean_object * check_cache(lean_object * a) {
if (!lean_is_exclusive(a)) {
// We only check the cache if `a` is a shared object
auto it = m_cache.find(a);
if (it != m_cache.end()) {
// All objects stored in the range of `m_cache` are single threaded.
lean_assert(lean_is_st(it->second));
// We increment the reference counter because this object
// will be returned by `lean_sharecommon_quick` or stored into a new object.
it->second->m_rc++;
return it->second;
lean_object * sharecommon_quick_fn::check_cache(lean_object * a) {
if (!lean_is_exclusive(a)) {
// We only check the cache if `a` is a shared object
auto it = m_cache.find(a);
if (it != m_cache.end()) {
// All objects stored in the range of `m_cache` are single threaded.
lean_assert(lean_is_st(it->second));
// We increment the reference counter because this object
// will be returned by `lean_sharecommon_quick` or stored into a new object.
it->second->m_rc++;
return it->second;
}
if (m_check_set) {
auto it = m_set.find(a);
if (it != m_set.end()) {
lean_object * result = *it;
lean_assert(lean_is_st(result));
result->m_rc++;
return result;
}
}
return nullptr;
}
return nullptr;
}
/*
`new_a` is a new object that is equal to `a`, but its subobjects are maximally shared.
*/
lean_object * save(lean_object * a, lean_object * new_a) {
lean_assert(lean_is_st(new_a));
lean_assert(new_a->m_rc == 1);
auto it = m_set.find(new_a);
lean_object * result;
if (it == m_set.end()) {
// `new_a` is a new object
m_set.insert(new_a);
result = new_a;
} else {
// We already have a maximally shared object that is equal to `new_a`
result = *it;
DEBUG_CODE({
if (lean_is_ctor(new_a)) {
lean_assert(lean_is_ctor(result));
unsigned num_objs = lean_ctor_num_objs(new_a);
lean_assert(lean_ctor_num_objs(result) == num_objs);
for (unsigned i = 0; i < num_objs; i++) {
lean_assert(lean_ctor_get(result, i) == lean_ctor_get(new_a, i));
}
/*
`new_a` is a new object that is equal to `a`, but its subobjects are maximally shared.
*/
lean_object * sharecommon_quick_fn::save(lean_object * a, lean_object * new_a) {
lean_assert(lean_is_st(new_a));
lean_assert(new_a->m_rc == 1);
auto it = m_set.find(new_a);
lean_object * result;
if (it == m_set.end()) {
// `new_a` is a new object
m_set.insert(new_a);
result = new_a;
} else {
// We already have a maximally shared object that is equal to `new_a`
result = *it;
DEBUG_CODE({
if (lean_is_ctor(new_a)) {
lean_assert(lean_is_ctor(result));
unsigned num_objs = lean_ctor_num_objs(new_a);
lean_assert(lean_ctor_num_objs(result) == num_objs);
for (unsigned i = 0; i < num_objs; i++) {
lean_assert(lean_ctor_get(result, i) == lean_ctor_get(new_a, i));
}
});
lean_dec_ref(new_a); // delete `new_a`
// All objects in `m_set` are single threaded.
lean_assert(lean_is_st(result));
result->m_rc++;
lean_assert(result->m_rc > 1);
}
if (!lean_is_exclusive(a)) {
// We only cache the result if `a` is a shared object.
m_cache.insert(std::make_pair(a, result));
}
lean_assert(result == new_a || result->m_rc > 1);
lean_assert(result != new_a || result->m_rc == 1);
return result;
}
});
lean_dec_ref(new_a); // delete `new_a`
// All objects in `m_set` are single threaded.
lean_assert(lean_is_st(result));
result->m_rc++;
lean_assert(result->m_rc > 1);
}
if (!lean_is_exclusive(a)) {
// We only cache the result if `a` is a shared object.
m_cache.insert(std::make_pair(a, result));
}
lean_assert(result == new_a || result->m_rc > 1);
lean_assert(result != new_a || result->m_rc == 1);
return result;
}
// `sarray` and `string`
lean_object * visit_terminal(lean_object * a) {
auto it = m_set.find(a);
if (it == m_set.end()) {
m_set.insert(a);
} else {
a = *it;
}
lean_inc_ref(a);
// `sarray` and `string`
lean_object * sharecommon_quick_fn::visit_terminal(lean_object * a) {
auto it = m_set.find(a);
if (it == m_set.end()) {
m_set.insert(a);
} else {
a = *it;
}
lean_inc_ref(a);
return a;
}
lean_object * sharecommon_quick_fn::visit_array(lean_object * a) {
lean_object * r = check_cache(a);
if (r != nullptr) { lean_assert(r->m_rc > 1); return r; }
size_t sz = array_size(a);
lean_array_object * new_a = (lean_array_object*)lean_alloc_array(sz, sz);
for (size_t i = 0; i < sz; i++) {
lean_array_set_core((lean_object*)new_a, i, visit(lean_array_get_core(a, i)));
}
return save(a, (lean_object*)new_a);
}
lean_object * sharecommon_quick_fn::visit_ctor(lean_object * a) {
lean_object * r = check_cache(a);
if (r != nullptr) { lean_assert(r->m_rc > 1); return r; }
unsigned num_objs = lean_ctor_num_objs(a);
unsigned tag = lean_ptr_tag(a);
unsigned sz = lean_object_byte_size(a);
unsigned scalar_offset = sizeof(lean_object) + num_objs*sizeof(void*);
unsigned scalar_sz = sz - scalar_offset;
lean_object * new_a = lean_alloc_ctor(tag, num_objs, scalar_sz);
for (unsigned i = 0; i < num_objs; i++) {
lean_ctor_set(new_a, i, visit(lean_ctor_get(a, i)));
}
if (scalar_sz > 0) {
memcpy(reinterpret_cast<char*>(new_a) + scalar_offset, reinterpret_cast<char*>(a) + scalar_offset, scalar_sz);
}
return save(a, new_a);
}
/*
**TODO:** We did not implement stack overflow detection.
We claim it is not needed in the current uses of `shareCommon'`.
If this becomes an issue, we can use the following approach to address the issue without
affecting the performance.
- Add an extra `depth` parameter.
- In `operator()`, estimate the maximum depth based on the remaining stack space. See `check_stack`.
- If the limit is reached, simply return `a`.
*/
lean_object * sharecommon_quick_fn::visit(lean_object * a) {
if (lean_is_scalar(a)) {
return a;
}
lean_object * visit_array(lean_object * a) {
lean_object * r = check_cache(a);
if (r != nullptr) { lean_assert(r->m_rc > 1); return r; }
size_t sz = array_size(a);
lean_array_object * new_a = (lean_array_object*)lean_alloc_array(sz, sz);
for (size_t i = 0; i < sz; i++) {
lean_array_set_core((lean_object*)new_a, i, visit(lean_array_get_core(a, i)));
}
return save(a, (lean_object*)new_a);
}
lean_object * visit_ctor(lean_object * a) {
lean_object * r = check_cache(a);
if (r != nullptr) { lean_assert(r->m_rc > 1); return r; }
unsigned num_objs = lean_ctor_num_objs(a);
unsigned tag = lean_ptr_tag(a);
unsigned sz = lean_object_byte_size(a);
unsigned scalar_offset = sizeof(lean_object) + num_objs*sizeof(void*);
unsigned scalar_sz = sz - scalar_offset;
lean_object * new_a = lean_alloc_ctor(tag, num_objs, scalar_sz);
for (unsigned i = 0; i < num_objs; i++) {
lean_ctor_set(new_a, i, visit(lean_ctor_get(a, i)));
}
if (scalar_sz > 0) {
memcpy(reinterpret_cast<char*>(new_a) + scalar_offset, reinterpret_cast<char*>(a) + scalar_offset, scalar_sz);
}
return save(a, new_a);
}
public:
switch (lean_ptr_tag(a)) {
/*
**TODO:** We did not implement stack overflow detection.
We claim it is not needed in the current uses of `shareCommon'`.
If this becomes an issue, we can use the following approach to address the issue without
affecting the performance.
- Add an extra `depth` parameter.
- In `operator()`, estimate the maximum depth based on the remaining stack space. See `check_stack`.
- If the limit is reached, simply return `a`.
Similarly to `sharecommon_fn`, we only maximally share arrays, scalar arrays, strings, and
constructor objects.
*/
lean_object * visit(lean_object * a) {
if (lean_is_scalar(a)) {
return a;
}
switch (lean_ptr_tag(a)) {
/*
Similarly to `sharecommon_fn`, we only maximally share arrays, scalar arrays, strings, and
constructor objects.
*/
case LeanMPZ: lean_inc_ref(a); return a;
case LeanClosure: lean_inc_ref(a); return a;
case LeanThunk: lean_inc_ref(a); return a;
case LeanTask: lean_inc_ref(a); return a;
case LeanRef: lean_inc_ref(a); return a;
case LeanExternal: lean_inc_ref(a); return a;
case LeanReserved: lean_inc_ref(a); return a;
case LeanScalarArray: return visit_terminal(a);
case LeanString: return visit_terminal(a);
case LeanArray: return visit_array(a);
default: return visit_ctor(a);
}
case LeanMPZ: lean_inc_ref(a); return a;
case LeanClosure: lean_inc_ref(a); return a;
case LeanThunk: lean_inc_ref(a); return a;
case LeanTask: lean_inc_ref(a); return a;
case LeanRef: lean_inc_ref(a); return a;
case LeanExternal: lean_inc_ref(a); return a;
case LeanReserved: lean_inc_ref(a); return a;
case LeanScalarArray: return visit_terminal(a);
case LeanString: return visit_terminal(a);
case LeanArray: return visit_array(a);
default: return visit_ctor(a);
}
lean_object * operator()(lean_object * a) {
return visit(a);
}
};
}
// def ShareCommon.shareCommon' (a : A) : A := a
extern "C" LEAN_EXPORT obj_res lean_sharecommon_quick(obj_arg a) {
return sharecommon_quick_fn()(a);
}
lean_object * sharecommon_persistent_fn::operator()(lean_object * e) {
lean_object * r = check_cache(e);
if (r != nullptr)
return r;
m_saved.push_back(object_ref(e, true));
r = visit(e);
m_saved.push_back(object_ref(r, true));
return r;
}
};

71
src/runtime/sharecommon.h Normal file
View File

@@ -0,0 +1,71 @@
/*
Copyright (c) 2024 Amazon.com, Inc. or its affiliates. All Rights Reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#pragma once
#include <vector>
#include <unordered_map>
#include <unordered_set>
#include "runtime/object_ref.h"
namespace lean {
extern "C" LEAN_EXPORT uint8 lean_sharecommon_eq(b_obj_arg o1, b_obj_arg o2);
extern "C" LEAN_EXPORT uint64_t lean_sharecommon_hash(b_obj_arg o);
/*
A faster version of `sharecommon_fn` which only uses a local state.
It optimizes the number of RC operations, the strategy for caching results,
and uses C++ hashmap.
*/
class sharecommon_quick_fn {
protected:
struct set_hash {
std::size_t operator()(lean_object * o) const { return lean_sharecommon_hash(o); }
};
struct set_eq {
std::size_t operator()(lean_object * o1, lean_object * o2) const { return lean_sharecommon_eq(o1, o2); }
};
/*
We use `m_cache` to ensure we do **not** traverse a DAG as a tree.
We use pointer equality for this collection.
*/
std::unordered_map<lean_object *, lean_object *> m_cache;
/* Set of maximally shared terms. AKA hash-consing table. */
std::unordered_set<lean_object *, set_hash, set_eq> m_set;
/*
If `true`, `check_cache` will also check `m_set`.
This is useful when the input term may contain terms that have already
been hashconsed.
*/
bool m_check_set;
lean_object * check_cache(lean_object * a);
lean_object * save(lean_object * a, lean_object * new_a);
lean_object * visit_terminal(lean_object * a);
lean_object * visit_array(lean_object * a);
lean_object * visit_ctor(lean_object * a);
lean_object * visit(lean_object * a);
public:
sharecommon_quick_fn(bool s = false):m_check_set(s) {}
void set_check_set(bool f) { m_check_set = f; }
lean_object * operator()(lean_object * a) {
return visit(a);
}
};
/*
Similar to `sharecommon_quick_fn`, but we save the entry points and result values to ensure
they are not deleted.
*/
class sharecommon_persistent_fn : private sharecommon_quick_fn {
std::vector<object_ref> m_saved;
public:
sharecommon_persistent_fn(bool s = false):sharecommon_quick_fn(s) {}
void set_check_set(bool f) { m_check_set = f; }
lean_object * operator()(lean_object * e);
};
};

View File

@@ -8,4 +8,4 @@
1007.lean:39:4-39:7: warning: declaration uses 'sorry'
1007.lean:56:64-56:78: error: failed to synthesize
IsLin fun x => sum fun i => norm x
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
1102.lean:22:35-22:49: error: failed to synthesize
DVR 1
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,12 +1,12 @@
2040.lean:8:8-8:13: error: failed to synthesize
HPow Nat Nat Int
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
2040.lean:14:8-14:13: error: failed to synthesize
HPow Nat Nat Int
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
2040.lean:20:8-20:13: error: failed to synthesize
HPow Nat Nat Int
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
2040.lean:18:2-20:22: error: type mismatch
trans (sorryAx (a = 37)) (sorryAx (37 = 2 ^ n))
has type

View File

@@ -8,11 +8,11 @@
@HPow.hPow Int Nat Int Int.instHPowNat (@OfNat.ofNat Int 3 (@instOfNat 3)) (@OfNat.ofNat Nat 2 (instOfNatNat 2)) : Int
2220.lean:25:19-25:24: error: failed to synthesize
HPow Nat Nat Int
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
@HAdd.hAdd Int Int Int (@instHAdd Int Int.instAdd) (@OfNat.ofNat Int 1 (@instOfNat 1))
(@HPow.hPow Nat Nat Int ?m (@OfNat.ofNat Nat 3 (instOfNatNat 3)) (@OfNat.ofNat Nat 2 (instOfNatNat 2))) : Int
2220.lean:26:12-26:17: error: failed to synthesize
HPow Nat Nat Int
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
@HAdd.hAdd Int Int Int (@instHAdd Int Int.instAdd) (@OfNat.ofNat Int 1 (@instOfNat 1))
(@HPow.hPow Nat Nat Int ?m (@OfNat.ofNat Nat 3 (instOfNatNat 3)) (@OfNat.ofNat Nat 2 (instOfNatNat 2))) : Int

View File

@@ -1,3 +1,3 @@
2273.lean:9:8-9:14: error: failed to synthesize
P 37
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -5,5 +5,5 @@ set_option pp.all true in
#check fun {α : Sort v} => PEmpty.rec (fun _ => α)
-- but `def` doesn't work
-- error: (kernel) compiler failed to infer low level type, unknown declaration 'PEmpty.rec'
-- error: code generator does not support recursor 'PEmpty.rec' yet
def PEmpty.elim' {α : Sort v} := PEmpty.rec (fun _ => α)

View File

@@ -1,3 +1,2 @@
276.lean:5:27-5:50: error: failed to elaborate eliminator, expected type is not available
fun {α : Sort v} => @?m α : {α : Sort v} → @?m α
276.lean:9:33-9:56: error: failed to elaborate eliminator, expected type is not available
fun {α : Sort v} => PEmpty.rec.{v, u_1} fun (x : PEmpty.{u_1}) => α : {α : Sort v} → PEmpty.{u_1} → α
276.lean:9:4-9:16: error: code generator does not support recursor 'PEmpty.rec' yet, consider using 'match ... with' and/or structural recursion

View File

@@ -3,4 +3,4 @@
numerals are polymorphic in Lean, but the numeral `0` cannot be used in a context where the expected type is
Sort ?u
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
386.lean:9:2-9:46: error: failed to synthesize
Fintype ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
448.lean:21:2-23:20: error: failed to synthesize
MonadExceptOf IO.Error M
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
attrCmd.lean:6:0-6:6: error: failed to synthesize
Pure M
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -12,7 +12,7 @@ calcErrors.lean:24:8-24:11: error: invalid 'calc' step, relation expected
p a
calcErrors.lean:31:8-31:13: error: invalid 'calc' step, failed to synthesize `Trans` instance
Trans p p ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
calcErrors.lean:41:7-41:12: error: invalid 'calc' step, left-hand-side is
γ : Sort u_1
previous right-hand-side is

View File

@@ -6,6 +6,7 @@
let inst✝ := decEqListTree✝ @a✝ @b✝;
if h✝ : @a✝ = @b✝ then by subst h✝; exact isTrue✝ rfl✝
else isFalse✝ (by intro n✝; injection n✝; apply h✝ _; assumption)
termination_by structural x✝
private def decEqListTree✝ (x✝² : @ListTree✝) (x✝³ : @ListTree✝) : Decidable✝ (x✝² = x✝³) :=
match x✝², x✝³ with
| @ListTree.nil, @ListTree.nil => isTrue✝¹ rfl✝¹
@@ -19,6 +20,7 @@
if h✝³ : @a✝² = @b✝² then by subst h✝³; exact isTrue✝² rfl✝²
else isFalse✝² (by intro n✝¹; injection n✝¹; apply h✝³ _; assumption)
else isFalse✝³ (by intro n✝²; injection n✝²; apply h✝² _; assumption)
termination_by structural x✝²
end,
instance : DecidableEq✝ (@ListTree✝) :=
decEqListTree✝]
@@ -33,18 +35,21 @@
let inst✝ := decEqFoo₂✝ @a✝ @b✝;
if h✝¹ : @a✝ = @b✝ then by subst h✝¹; exact isTrue✝¹ rfl✝¹
else isFalse✝¹ (by intro n✝; injection n✝; apply h✝¹ _; assumption)
termination_by structural x✝
private def decEqFoo₂✝ (x✝² : @Foo₂✝) (x✝³ : @Foo₂✝) : Decidable✝ (x✝² = x✝³) :=
match x✝², x✝³ with
| @Foo₂.foo₂ a✝¹, @Foo₂.foo₂ b✝¹ =>
let inst✝¹ := decEqFoo₃✝ @a✝¹ @b✝¹;
if h✝² : @a✝¹ = @b✝¹ then by subst h✝²; exact isTrue✝² rfl✝²
else isFalse✝² (by intro n✝¹; injection n✝¹; apply h✝² _; assumption)
termination_by structural x✝²
private def decEqFoo₃✝ (x✝⁴ : @Foo₃✝) (x✝⁵ : @Foo₃✝) : Decidable✝ (x✝⁴ = x✝⁵) :=
match x✝⁴, x✝⁵ with
| @Foo₃.foo₃ a✝², @Foo₃.foo₃ b✝² =>
let inst✝² := decEqFoo₁✝ @a✝² @b✝²;
if h✝³ : @a✝² = @b✝² then by subst h✝³; exact isTrue✝³ rfl✝³
else isFalse✝³ (by intro n✝²; injection n✝²; apply h✝³ _; assumption)
termination_by structural x✝⁴
end,
instance : DecidableEq✝ (@Foo₁✝) :=
decEqFoo₁✝]

View File

@@ -1,7 +1,7 @@
[4, 5, 6]
defInst.lean:8:26-8:32: error: failed to synthesize
BEq Foo
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
fun x y => sorryAx (?m x y) true : (x y : Foo) → ?m x y
[4, 5, 6]
fun x y => x == y : Foo → Foo → Bool

View File

@@ -1,5 +1,5 @@
defaultInstance.lean:20:20-20:23: error: failed to synthesize
Foo Bool (?m x)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
defaultInstance.lean:22:35-22:38: error: typeclass instance problem is stuck, it is often due to metavariables
Foo Bool (?m x)

View File

@@ -1,51 +0,0 @@
/-!
# Testing features of the app delaborator, including overapplication
-/
/-!
Check that the optional value equality check is specialized to the supplied arguments
(rather than, formerly, the locally-defined fvars from a telescope).
-/
def foo (α : Type) [Inhabited α] (x : α := default) : α := x
#check foo Nat
#check foo Nat 1
/-!
Check that optional value omission is aware of unfolding.
-/
def Ty := (x : Nat := 1) Fin (x + 1)
def f (y : Nat := 2) : Ty := fun x => 0
#check f 3 4
#check f 3
#check (f)
/-!
Check that overapplied projections pretty print using projection notation.
-/
structure Foo where
f : Nat Nat
#check (x : Foo), x.f 1 = 0
/-!
Overapplied `letFun`
-/
#check (have f := id; f) 1
/-!
Overapplied `OfNat.ofNat`
-/
instance : OfNat (Nat Nat) 1 where
ofNat := id
#check (1 : Nat Nat) 2
/-!
Overapplied `dite`
-/
#check (if h : True then id else id) 1

View File

@@ -1,11 +0,0 @@
foo Nat : Nat
foo Nat 1 : Nat
f 3 4 : Fin (4 + 1)
f 3 : Fin (1 + 1)
f 2 : Fin (1 + 1)
∀ (x : Foo), x.f 1 = 0 : Prop
(let_fun f := id;
f)
1 : Nat
1 2 : Nat
(if h : True then id else id) 1 : Nat

View File

@@ -1,6 +1,6 @@
eagerUnfoldingIssue.lean:6:2-6:17: error: failed to synthesize
MonadLog (StateM Nat)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
eagerUnfoldingIssue.lean:12:2-12:17: error: failed to synthesize
MonadLog (StateM Nat)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
eraseInsts.lean:12:22-12:27: error: failed to synthesize
HAdd Foo Foo ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
forErrors.lean:3:29-3:30: error: failed to synthesize
ToStream α ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -1,3 +1,3 @@
kernelMVarBug.lean:5:15-5:20: error: failed to synthesize
HAdd α α α
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.

View File

@@ -11,7 +11,7 @@ while expanding
macroStack.lean:11:9-11:15: error: invalid use of `(<- ...)`, must be nested inside a 'do' expression
macroStack.lean:17:0-17:6: error: failed to synthesize
HAdd Nat String ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
with resulting expansion
binop% HAdd.hAdd✝ (x + x✝) x✝¹
while expanding

View File

@@ -1,6 +1,6 @@
macroSwizzle.lean:4:7-4:23: error: failed to synthesize
HAdd Bool String ?m
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
macroSwizzle.lean:6:7-6:10: error: application type mismatch
Nat.succ "x"
argument

View File

@@ -1,7 +1,7 @@
openScoped.lean:1:7-1:14: error: unknown identifier 'epsilon'
openScoped.lean:4:2-4:24: error: failed to synthesize
Decidable (f = g)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
Classical.epsilon.{u} {α : Sort u} [h : Nonempty α] (p : α → Prop) : α
openScoped.lean:15:7-15:14: error: unknown identifier 'epsilon'
openScoped.lean:20:7-20:14: error: unknown identifier 'epsilon'

View File

@@ -7,7 +7,7 @@ prvCtor.lean:27:7-27:8: error: unknown identifier 'a'
prvCtor.lean:29:25-29:27: error: overloaded, errors
failed to synthesize
EmptyCollection (Name "hello")
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
invalid {...} notation, constructor for `Name` is marked as private
prvCtor.lean:31:25-31:34: error: invalid ⟨...⟩ notation, constructor for `Name` is marked as private

View File

@@ -16,7 +16,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `0` cannot be used in a context where the expected type is
Bool
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
def x : Bool := 0
@@ -29,7 +29,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `0` cannot be used in a context where the expected type is
Bool
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
theorem result4 : False := by -- Does not generate a `sorry` warning because there is an error

View File

@@ -8,7 +8,7 @@ error: cannot evaluate expression that depends on the `sorry` axiom.
Use `#eval!` to evaluate nevertheless (which may cause lean to crash).
-/
#guard_msgs in
#eval show Nat from False.rec (by decide)
#eval show Nat from False.elim (by decide)
/--
warning: declaration uses 'sorry'

View File

@@ -41,7 +41,6 @@ info: [type_class] max synth pending failures (maxSynthPendingDepth: 1), use `se
---
error: failed to synthesize
HasQuotient (Synonym (Synonym R)) (Submodule R (Synonym (Synonym R)))
use `set_option diagnostics true` to get diagnostic information
-/
#guard_msgs in
set_option diagnostics true in

View File

@@ -6,7 +6,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
Sort _
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
axiom bla : 1
@@ -17,7 +17,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
Sort _
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
structure Foo where
@@ -29,7 +29,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
Sort _
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
inductive Bla (x : 1) : Type

View File

@@ -5,8 +5,12 @@ def foo : Nat → Nat
set_option debug.moduleNameAtTimeout false
/--
error: (deterministic) timeout, maximum number of heartbeats (100) has been reached
use `set_option maxHeartbeats <num>` to set the limit
use `set_option diagnostics true` to get diagnostic information
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout, maximum number of heartbeats (100) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
set_option maxHeartbeats 100 in

View File

@@ -17,7 +17,7 @@ instance instB10000 : B 10000 where
/--
error: failed to synthesize
A
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
#synth A -- should fail quickly

View File

@@ -14,7 +14,7 @@ def IsGood [DecidableEq dOut] [DecidableEq dOut₂] (Λ : Mappish dIn dOut) (Λ
/--
error: failed to synthesize
Fintype v
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
def MappishOrder [DecidableEq dIn] : Preorder

View File

@@ -37,7 +37,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
String
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
#check (1 : String)
@@ -48,7 +48,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
Bool
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
#check (1 : Bool)
@@ -59,7 +59,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `1` cannot be used in a context where the expected type is
Bool → Nat
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
#check (1 : Bool Nat)
@@ -70,7 +70,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `0` cannot be used in a context where the expected type is
String
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
def foo : String :=

View File

@@ -13,7 +13,7 @@ example (p : Prop) : True := by
/--
error: failed to synthesize
Decidable p
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
example (p : Prop) : True := by

View File

@@ -0,0 +1,79 @@
/-!
# Testing features of the app delaborator, including overapplication
-/
/-!
Check that the optional value equality check is specialized to the supplied arguments
(rather than, formerly, the locally-defined fvars from a telescope).
-/
def foo (α : Type) [Inhabited α] (x : α := default) : α := x
/-- info: foo Nat : Nat -/
#guard_msgs in #check foo Nat
/-- info: foo Nat 1 : Nat -/
#guard_msgs in #check foo Nat 1
/-!
Check that optional value omission is aware of unfolding.
-/
def Ty := (x : Nat := 1) Fin (x + 1)
def f (y : Nat := 2) : Ty := fun x => 0
/-- info: f 3 4 : Fin (4 + 1) -/
#guard_msgs in #check f 3 4
/-- info: f 3 : Fin (1 + 1) -/
#guard_msgs in #check f 3
/-- info: f : Fin (1 + 1) -/
#guard_msgs in #check (f)
/-!
Check that overapplied projections pretty print using projection notation.
-/
structure Foo where
f : Nat Nat
/-- info: ∀ (x : Foo), x.f 1 = 0 : Prop -/
#guard_msgs in #check (x : Foo), x.f 1 = 0
/-!
Overapplied `letFun`
-/
/--
info: (let_fun f := id;
f)
1 : Nat
-/
#guard_msgs in #check (have f := id; f) 1
/-!
Overapplied `OfNat.ofNat`
-/
instance : OfNat (Nat Nat) 1 where
ofNat := id
/-- info: 1 2 : Nat -/
#guard_msgs in #check (1 : Nat Nat) 2
/-!
Overapplied `dite`
-/
/-- info: (if _h : True then id else id) 1 : Nat -/
#guard_msgs in #check (if _h : True then id else id) 1
/-!
Testing that multiple optional arguments are omitted rather than just the last (issue #4812)
-/
def g (a : Nat) (b := 1) (c := 2) (d := 3) := a + b + c + d
/-- info: g 0 : Nat -/
#guard_msgs in #check g 0
-- Both the `start` and `stop` arguments are omitted.
/-- info: fun a => Array.foldl (fun x y => x + y) 0 a : Array Nat → Nat -/
#guard_msgs in #check fun (a : Array Nat) => a.foldl (fun x y => x + y) 0

View File

@@ -0,0 +1,20 @@
/-!
# Mentioning `set_option diagnostics true` depends on it not already being set
-/
/--
error: failed to synthesize
Coe Nat Int
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
#synth Coe Nat Int
set_option diagnostics true
/--
error: failed to synthesize
Coe Nat Int
-/
#guard_msgs in
#synth Coe Nat Int

View File

@@ -175,3 +175,14 @@ def leRecOn {C : Nat → Sort _} {n : Nat} : ∀ {m}, n ≤ m → (∀ {k}, C k
theorem leRecOn_self {C : Nat Sort _} {n} {next : {k}, C k C (k + 1)} (x : C n) :
(leRecOn n.le_refl next x : C n) = x :=
sorry
/-!
Issue https://github.com/leanprover/lean4/issues/4347
`False.rec` has `motive` as an explicit argument.
-/
example (h : False) : Nat := False.rec (fun _ => Nat) h
example (h : False) : Nat := False.rec _ h
example (h : False) : Nat := h.rec
example (h : False) : Nat := h.rec _

View File

@@ -3,7 +3,7 @@ import Lean
inductive MyEmpty
def f (x : MyEmpty) : Nat :=
MyEmpty.casesOn x
MyEmpty.casesOn _ x
set_option trace.Compiler.result true
/--

View File

@@ -51,7 +51,7 @@ error: failed to synthesize
numerals are polymorphic in Lean, but the numeral `22` cannot be used in a context where the expected type is
α
due to the absence of the instance above
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs(error) in
example : α := 22
@@ -107,7 +107,7 @@ Lax whitespace
/--
error: failed to synthesize
DecidableEq (Nat → Nat)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs (whitespace := lax) in
#synth DecidableEq (Nat Nat)
@@ -115,7 +115,7 @@ use `set_option diagnostics true` to get diagnostic information
/--
error: failed to synthesize
DecidableEq (Nat → Nat)
use `set_option diagnostics true` to get diagnostic information
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs (whitespace := lax) in
#synth DecidableEq (Nat Nat)

View File

@@ -52,8 +52,36 @@ where
/--
error: (deterministic) timeout at `whnf`, maximum number of heartbeats (400) has been reached
use `set_option maxHeartbeats <num>` to set the limit
use `set_option diagnostics true` to get diagnostic information
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `isDefEq`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `elaborator`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `isDefEq`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `isDefEq`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `elaborator`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `isDefEq`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
---
error: (deterministic) timeout at `whnf`, maximum number of heartbeats (400) has been reached
Use `set_option maxHeartbeats <num>` to set the limit.
Additional diagnostic information may be available using the `set_option diagnostics true` command.
-/
#guard_msgs in
set_option backward.isDefEq.lazyWhnfCore false in

View File

@@ -1,7 +1,3 @@
@[congr]
theorem exists_prop_congr {p p' : Prop} {q q' : p Prop} (hq : h, q h q' h) (hp : p p') :
Exists q h : p', q' (hp.2 h) := sorry
set_option maxHeartbeats 1000 in
example (x : Nat) :
(h : x = x)

View File

@@ -1,5 +1,13 @@
variable (a b : Nat)
/- bitwise operation tests -/
#check_simp (3 : Nat) &&& (1 : Nat) ~> 1
#check_simp (3 : Nat) ^^^ (1 : Nat) ~> 2
#check_simp (2 : Nat) ||| (1 : Nat) ~> 3
#check_simp (3 : Nat) <<< (2 : Nat) ~> 12
#check_simp (3 : Nat) >>> (1 : Nat) ~> 1
/- subtract diff tests -/
#check_simp (1000 : Nat) - 400 ~> 600

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