This PR updates the formatting of, and adds explanations for, "unknown
identifier" errors as well as "failed to infer type" errors for binders
and definitions.
It attempts to ameliorate some of the confusion encountered in #1592 by
modifying the wording of the "header is elaborated before body is
processed" note and adding further discussion and examples of this
behavior in the corresponding error explanation.
An earlier PR (#9017) replaced certain subarray functions such as
`Subarray.foldl` with generic slice functions `Slice.foldl`. For
backward compatibility reasons, This PR reintroduces `Subarray.foldl`
etc. as aliases for the `Slice` versions.
This PR fixes a performance issue that occurs when generating equation
lemmas for functions that use match-expressions containing several
literals. This issue was exposed by #9322 and arises from a combination
of factors:
1. Literal values are compiled into a chain of dependent if-then-else
expressions.
2. Dependent if-then-else expressions are significantly more expensive
to simplify than regular ones.
3. The `split` tactic selects a target, splits it, and then invokes
`simp` on the resulting subgoals. Moreover, `simp` traverses the entire
goal bottom-up and does not stop after reaching the target.
This PR addresses the issue by introducing a custom simproc that avoids
recursively simplifying nested if-then-else expressions. It does **not**
alter the user-facing behavior of the `split` tactic because such a
change would be highly disruptive. Instead, the PR adds a new flag,
`backward.split` to control the behavior of the user-facing `split`
tactic. It is currently set to `true`, i.e., the old behavior is still
the default one. In a future PR, we should set this flag to `false` by
default and begin repairing all affected proofs.
closes#9322
This PR modifies the encoding from `Nat` to `Int` used in `grind
cutsat`. It is simpler, more extensible, and similar to the generic
`ToInt`. After update stage0, we will be able to delete the leftovers.
This PR uses the `mkCongrSimpForConst?` API in `simp` to reduce the
number of times the same congruence lemma is generated. Before this PR,
`grind` would spend `1.5`s creating congruence theorems during
normalization in the `grind_bitvec2.lean` benchmark. It now spends
`0.6`s. This PR should make an even bigger difference after we merge
#9300.
This PR removes the unnecessary requirement of `BEq α` for
`Array.any_push`, `Array.any_push'`, `Array.all_push`, `Array.all_push'`
as well as `Vector.any_push` and `Vector.all_push`.
This PR replaces the `reduceCtorEq` simproc used in `grind` by a much
more efficient one. The default one use in `simp` is just overhead
because the `grind` normalizer is already normalizing arithmetic.
In a separate PR, we will push performance improvements to the default
`reduceCtorEq`.
This PR optimizes support for `Decidable` instances in `grind`. Because
`Decidable` is a subsingleton, the canonicalizer no longer wastes time
normalizing such instances, a significant performance bottleneck in
benchmarks like `grind_bitvec2.lean`. In addition, the
congruence-closure module now handles `Decidable` instances, and can
solve examples such as:
```lean
example (p q : Prop) (h₁ : Decidable p) (h₂ : Decidable (p ∧ q)) : (p ↔ q) → h₁ ≍ h₂ := by
grind
```
This PR improves the `congr` tactic so that it can handle function
applications with fewer arguments than the arity of the head function.
This also fixes a bug where `congr` could not make progress with
`Set`-valued functions in Mathlib, since `Set` was being unfolded and
making such functions have an apparently higher arity.
This addresses issue #2128 for the `congr` tactic, but not `simp` and
others.
This PR adds theorem `BitVec.clzAuxRec_eq_clzAuxRec_of_getLsbD_false` as
a more general statement than `BitVec.clzAuxRec_eq_clzAuxRec_of_le`,
replacing the latter in the bitblaster too.
This PR makes the logic and tactics of `Std.Do` universe polymorphic, at
the cost of a few definitional properties arising from the switch from
`Prop` to `ULift Prop` in the base case `SPred []`.
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
This PR migrates usages of `Std.Range` to the new polymorphic ranges.
This PR unfortunately increases the transitive imports for
frequently-used parts of `Init` because the ranges now rely on iterators
in order to provide their functionality for types other than `Nat`.
However, iteration over ranges in compiled code is as efficient as
before in the examples I checked. This is because of a special
`IteratorLoop` implementation provided in the PR for this purpose.
There were two issues that were uncovered during migration:
* In `IndPredBelow.lean`, migrating the last remaining range causes
`compilerTest1.lean` to break. I have minimized the issue and came to
the conclusion it's a compiler bug. Therefore, I have not replaced said
old range usage yet (see #9186).
* In `BRecOn.lean`, we are publicly importing the ranges. Making this
import private should theoretically work, but there seems to be a
problem with the module system, causing the build to panic later in
`Init.Data.Grind.Poly` (see #9185).
* In `FuzzyMatching.lean`, inlining fails with the new ranges, which
would have led to significant slowdown. Therefore, I have not migrated
this file either.
This PR extends the `Eq` simproc used in `grind`. It covers more cases
now. It also adds 3 reducible declarations to the list of declarations
to unfold.
This PR implements `exists` normalization using a simproc instead of
rewriting rules in grind. This is the first part of the PR, after update
stage0, we must remove the normalization theorems.
This PR implements `forall` normalization using a simproc instead of
rewriting rules in `grind`. This is the first part of the PR, after
update stage0, we must remove the normalization theorems.
This PR tries to improve the E-matching pattern inference for `grind`.
That said, we still need better tools for annotating and maintaining
`grind` annotations in libraries.
closes#9125
This PR removes the `Subarray`-specific `toArray`, `foldlM` and `foldl`
methods and instead provides these operations on `Std.Slice`, which are
implemented with the `ToIterator` instance of the slice. Calling
`subarray.toArray` etc. still works, since `Subarray` is an abbreviation
for `Slice _`.
Because the benchmarks are not so clear, to be safe, I will merge this
only after the release. In contrast to the ranges, the iteration over
slices is not quite as efficient as the old `Subarray`-specific
implementation, which would require either more optimizations in the
iterator library (special `IteratorLoop` and `IteratorCollect`
implementations) or better unboxing support by the compiler.
This PR resolves a defeq diamond, which caused a problem in Mathlib:
```
import Mathlib
example (R : Type) [I : Ring R] :
@AddCommGroup.toGrindIntModule R (@Ring.toAddCommGroup R I) =
@Lean.Grind.Ring.instIntModule R (@Ring.toGrindRing R I) := rfl -- fails
```
This PR fixes the syntax of `grind` modifiers to use `patternIgnore` for
cases where both unicode and ascii variants are matched. This fixes an
issue where several variants of grind syntax weren't accepted (e.g.
`@[grind ← gen]`). Additionally, this reduces the chance that we get
another syntax matching bootstrap hell.
This PR wraps `simpLemma` and `grindLemma` in `ppGroup` to make sure
that the modifiers aren't printed separately from the term / identifier.
Example:
```
simp only [very_long_lemma_oh_no_can_you_please_stop_we're_getting_to_the_limit, ←
wait_this_is_rewritten_backwards_oh_uhh_where's_the_arrow_you_ask?_oh_wait_it's_up_there!]
==>
simp only [very_long_lemma_oh_no_can_you_please_stop_we're_getting_to_the_limit,
← wait_this_is_rewritten_backwards_and_wow_it's_very_clear_and_obvious]
```
This PR removes a rather ugly hack in the module system, exposing the
bodies of theorems whose type mention `WellFounded`.
The original motivation was that reducing well-founded definitions (e.g.
in `by rfl`) requires reducing proofs, so they need to be available.
But reducing proofs is generally fraught with peril, and we have been
nudging our users away from using it for a while, e.g. in #5182. Since
the module system is opt-in and users will gradually migrate to it, it
may be reasonable to expect them to avoid reducing well-founded
recursion in the process
This way we don't need hacks like this (which, without evidence, I
believe would be incomplete anyways) and we get the nice guarantee that
within the module system, theorems bodies are always private.
This PR removes some unnecessary `Decidable*` instance arguments by
using lemmas in the `Classical` namespace instead of the `Decidable`
namespace.
This might lead to some additional dependency on classical axioms, but
large parts of the standard library are relying on them either way.
This PR fixes spacing in the `grind` attribute and tactic syntax.
Previously `@[grind]` was incorrectly pretty-printed as `@[grind ]`, and
`grind [...] on_failure ...` was pretty-printed `grind [...]on_failure
...`. Fixes that `on_failure` was reserved as keyword.
This PR moves the construction of the `Option.SomeLtNone.lt` (and `le`)
relation, in which `some` is less than `none`, to
`Init.Data.Option.Basic` and moves well-foundedness proofs for
`Option.lt` and `Option.SomeLtNone.lt` into `Init.Data.Option.Lemmas`.
This PR removes the `irreducible` attribute from `letFun`, which is one
step toward removing special `letFun` support; part of #9086.
Removing the attribute seems to break some `module` tests in stage2.
This PR adds an unexpander for `OfSemiring.toQ`. This an auxiliary
function used by the `ring` module in `grind`, but we want to reduce the
clutter in the diagnostic information produced by `grind`. Example:
```
example [CommSemiring α] [AddRightCancel α] [IsCharP α 0] (x y : α)
: x^2*y = 1 → x*y^2 = y → x + y = 2 → False := by
grind
```
produces
```
[ring] Ring `Ring.OfSemiring.Q α` ▼
[basis] Basis ▼
[_] ↑x + ↑y + -2 = 0
[_] ↑y + -1 = 0
```
