This PR reworks the `simp` set around the `Id` monad, to not elide or
unfold `pure` and `Id.run`
In particular, it stops encoding the "defeq abuse" of `Id X = X` in the
statements of theorems, instead using `Id.run` and `pure` to pass back
and forth between these two spellings. Often when writing these with
`pure`, they generalize to other lawful monads; though such changes were
split off to other PRs.
This fixes the problem with the current simp set where `Id.run (pure x)`
is simplified to `Id.run x`, instead of the desirable `x`.
This is particularly bad because the` x` is sometimes inferred with type
`Id X` instead of `X`, which prevents other `simp` lemmas about `X` from
firing.
Making `Id` reducible instead is not an option, as then the `Monad`
instances would have nothing to key on.
---------
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR adds the `List/Array/Vector.ofFnM`, the monadic analogues of
`ofFn`, along with basic theory.
At the same time we pave some potholes in nearby API.
---------
Co-authored-by: Eric Wieser <wieser.eric@gmail.com>
This PR adjusts the experimental module system to not export the bodies
of `def`s unless opted out by the new attribute `@[expose]` on the `def`
or on a surrounding `section`.
---------
Co-authored-by: Markus Himmel <markus@lean-fro.org>
This PR adds simp/grind lemmas about `List`/`Array`/`Vector.contains`.
In the presence of `LawfulBEq` these effectively already held, via
simplifying `contains` to `mem`, but now these also fire without
`LawfulBEq`.
This PR adds an initial set of `@[grind]` annotations for
`List`/`Array`/`Vector`, enough to set up some regression tests using
`grind` in proofs about `List`. More annotations to follow.
This PR moves `ReflBEq` to `Init.Core` and changes `LawfulBEq` to extend
`ReflBEq`.
**BREAKING CHANGES:**
- The `refl` field of `ReflBEq` has been renamed to `rfl` to match
`LawfulBEq`
- `LawfulBEq` extends `ReflBEq`, so in particular `LawfulBEq.rfl` is no
longer valid
This PR reviews the implicitness of arguments across List/Array/Vector,
generally trying to make arguments implicit where possible, although
sometimes correcting propositional arguments which were incorrectly
implicit to explicit.
This PR makes functions defined by well-founded recursion use an
`opaque` well-founded proof by default. This reliably prevents kernel
reduction of such definitions and proofs, which tends to be
prohibitively slow (fixes#2171), and which regularly causes
hard-to-debug kernel type-checking failures. This changes renders
`unseal` ineffective for such definitions. To avoid the opaque proof,
annotate the function definition with `@[semireducible]`.
This PR takes Array-specific lemmas at the end of `Array/Lemmas.lean`
(i.e. material that does not have exact correspondences with
`List/Lemmas.lean`) and moves them to more appropriate homes. More to
come.
This PR adds `Array.replace` and `Vector.replace`, proves the
correspondences with `List.replace`, and reproduces the basic API. In
order to do so, it fills in some gaps in the `List.findX` APIs.
This PR moves away from using `List.get` / `List.get?` / `List.get!` and
`Array.get!`, in favour of using the `GetElem` mediated getters. In
particular it deprecates `List.get?`, `List.get!` and `Array.get?`. Also
adds `Array.back`, taking a proof, matching `List.getLast`.
This PR aligns current coverage of `find`-type theorems across
`List`/`Array`/`Vector`. There are still quite a few holes in this API,
which will be filled later.
This PR makes `take`/`drop`/`extract` available for each of
`List`/`Array`/`Vector`. The simp normal forms differ, however: in
`List`, we simplify `extract` to `take+drop`, while in `Array` and
`Vector` we simplify `take` and `drop` to `extract`. We also provide
`Array/Vector.shrink`, which simplifies to `take`, but is implemented by
repeatedly popping. Verification lemmas for `Array/Vector.extract` to
follow in a subsequent PR.
This PR adds missing monadic higher order functions on
`List`/`Array`/`Vector`. Only the most basic verification lemmas
(relating the operations on the three container types) are provided for
now.
