This PR fixes disequality propagation for constructor applications in
`grind`. The equivalence class representatives may be distinct
constructor applications, but we must ensure they have the same type.
Examples that were panic'ing before this PR:
```lean
example (a b : List Nat)
: a ≍ ([] : List Int) → b ≍ ([1] : List Int) → a = b ∨ p → p := by
grind
example (a b : List Nat)
: a = [] → a ≍ ([] : List Int) → b = [1] → a = b ∨ p → p := by
grind
example (a b : List Nat)
: a = [] → a ≍ ([] : List Int) → b = [1] → b ≍ [(1 : Int)] → a = b ∨ p → p := by
grind
example (a b : List Nat)
: a = [] → b = [1] → a = b ∨ p → p := by
grind
example (a b : List Nat)
: a = [] → a ≍ ([] : List Int) → b = [1] → a = b ∨ p → p := by
grind
```
Closes#11124
This PR lets the match compilation procedure use sparse case analysis
when the patterns only match on some but not all constructors of an
inductive type. This way, less code is produce. Before, code handling
each of the other cases was then optimized and commoned-up by later
compilation pipeline, but that is wasteful to do.
In some cases this will prevent Lean from noticing that a match
statement is complete
because it performs less case-splitting for the unreachable case. In
this case, give explicit
patterns to perform the deeper split with `by contradiction` as the
right-hand side.
At least temporarily, there is also the option to disable this behaviour
with
```
set_option backwards.match.sparseCases false
```
This PR adds “sparse casesOn” constructions. They are similar to
`.casesOn`, but have arms only for some constructors and a catch-all
(providing `t.ctorIdx ≠ 42` assumptions). The compiler has native
support for these constructors and now (because of the similarity) also
the per-constructor elimination principles.
This PR ensures that the `denote` functions used to implement
proof-by-reflection terms in `grind` are abbreviations. This change
eliminates the need for the `withAbstractAtoms` gadget.
This PR fixes a panic during equality propagation in the `grind ring`
module. If the maximum number of steps has been reached, the polynomials
may not be fully simplified.
Closes#11073
This PR implements equality propagation for `Nat` in `grind order`.
`grind order` supports offset equalities for rings, but it has an
adapter for `Nat`. Example:
```lean
example (a b : Nat) (f : Nat → Int) : a ≤ b + 1 → b + 1 ≤ a → f (1 + a) = f (1 + b + 1) := by
grind -offset -mbtc -lia -linarith (splits := 0)
```
This PR implements (nested term) equality propagation in `grind order`.
That is, it propagates implied equalities from `grind order` back to the
`grind` core. Examples:
```lean
open Lean Grind Std
example [LE α] [IsPartialOrder α] (a b : α) (f : α → Nat) : a ≤ b → b ≤ c → c ≤ a → f a = f b := by
grind (splits := 0)
example [CommRing α] [LE α] [LT α] [LawfulOrderLT α] [IsPartialOrder α] [OrderedRing α]
(a b : α) (f : α → Int) : a ≤ b + 1 → b ≤ a - 1 → f a = f (2 + b - 1) := by
grind -mbtc -lia -linarith (splits := 0)
example (a b : Int) (f : Int → Int) : a ≤ b + 1 → b ≤ a - 1 → f a = f (2 + b - 1) := by
grind -mbtc -lia -linarith (splits := 0)
```
This PR adds a new suggestion to `finish?`. It now generates the `grind`
tactic script as before, and a `finish only` tactic. Example:
```lean
/--
info: Try these:
[apply] ⏎
instantiate only [findIdx, insert, = mem_indices_of_mem]
instantiate only [= getElem?_neg, = getElem?_pos]
cases #1bba
· instantiate only [findIdx]
· instantiate only
instantiate only [= HashMap.mem_insert, = HashMap.getElem_insert]
[apply] finish only [findIdx, insert, = mem_indices_of_mem, = getElem?_neg, = getElem?_pos, = HashMap.mem_insert,
= HashMap.getElem_insert, #1bba]
-/
example (m : IndexMap α β) (a : α) (b : β) :
(m.insert a b).findIdx a = if h : a ∈ m then m.findIdx a else m.size := by
grind => finish?
```
This PR establishes `String.ofList` and `String.toList` as the preferred
method for converting between strings and lists of characters and
deprecates the alternatives `String.mk`, `List.asString` and
`String.data`.
This PR improves match compilation: Branch on variables in the order
suggested by the first remaining alternative, and do not branch when the
first remaining alternative does not require it. This fixes
https://github.com/leanprover/lean4/issues/10749. With `set_option
backwards.match.rowMajor false` the old behavior can be turned on.
(For now this is an experiment to get familiar with the code and the
whole
problem domain. It is likely overly naive.)
This PR extracts some refactorings from #10763, including dropping dead
code and not failing in `inaccessibleAsCtor`, which leadas to (slightly)
better error messages, and also on the grounds that the failing
alternative may actually be unreachable.
This PR adds support for specifying anchors to restrict the search space
in `grind` when using `grind only`. Anchors can limit which case splits
are performed and which local lemmas are instantiated.
This PR tries to preserve names of pattern variables in match
alternatives in `decreasing_by`, by telescoping into the concrete
alternative rather than the type of the matcher's alt. Fixes#10976.
This PR implements the following `grind` improvements:
1. `set_option` can now be used to set `grind` configuration options in
the interactive mode.
2. Fixes a bug in the repeated theorem instantiation detection.
3. Adds the macro `use [...]` as a shorthand for `instantiate only
[...]`.
This PR adds the combinator ` · t_1 ... t_n` to the `grind` interactive
mode. The `finish?` tactic now generates scripts using this combinator
to conform to Mathlib coding standards. The new format is also more
compact. Example:
```lean
/--
info: Try this:
[apply] ⏎
instantiate only [= mem_indices_of_mem, insert, = getElem_def]
instantiate only [= getElem?_neg, = getElem?_pos]
cases #f590
· cases #ffdf
· instantiate only
instantiate only [= Array.getElem_set]
· instantiate only
instantiate only [size, = HashMap.mem_insert, = HashMap.getElem_insert, = Array.getElem_push]
· instantiate only [= mem_indices_of_mem, = getElem_def]
instantiate only [usr getElem_indices_lt]
instantiate only [size]
cases #ffdf
· instantiate only [=_ WF]
instantiate only [= getElem?_neg, = getElem?_pos, = Array.getElem_set]
instantiate only [WF']
· instantiate only
instantiate only [= HashMap.mem_insert, = HashMap.getElem_insert, = Array.getElem_push]
-/
#guard_msgs in
example (m : IndexMap α β) (a a' : α) (b : β) (h : a' ∈ m.insert a b) :
(m.insert a b)[a'] = if h' : a' == a then b else m[a'] := by
grind => finish?
```
This PR ensures that model-based theory combination in `grind cutsat`
considers nonlinear terms. Nonlinear multiplications such as `x * y` are
treated as uninterpreted symbols in `cutsat`.
Closes#10885
This PR adds support for scientific literals for `Rat` in `grind`.
`grind` does not yet add support for this kind of literal in arbitrary
fields.
closes#10489
This PR fixes a bug in the equality propagation procedure in
`grind.order`. Specifically, it affects the procedure that asserts
equalities in the `grind` core state that are implied by (ring)
inequalities in the `grind.order` module.
closes#10622
This is a guard against #10705; if a kernel error is raised when the
return value of this function is eventually checked, it is often
silenced downstream, making it hard to spot the failure.
If we panic here via `assert!`, then the diagnostic cannot be missed.
This PR adds the `mbtc` tactic to the `grind` interactive mode. It
implements model-based theory combination. It also ensures `finish?` is
capable of generating it.
This PR ensures that solver propagation steps are necessary in the
generated tactic script to close the goal.
It produces more compact proof scripts, but this is not just an
optimization, if we include an unnecessary step, we may fail to replay
the generated script when `cases` steps are pruned using
non-chronological backtracking (NCB). For example, when executing
`finish?`, we may have performed a `cases #<anchor>` step that enabled
`ring` to propagate a new fact. If this fact is not used in the final
proof, and the corresponding `cases #<anchor>` step is pruned by NCB,
the `ring` step will fail during replay.
This PR ensures that `finish?` produces partial tactic scripts
containing `sorry`s.
We may add an option to disable this feature in the future.
It is enabled by default because it provides a useful way to debug
`grind` failures.
This PR topologically sorts abstracted vars in
`Meta.Closure.mkValueTypeClosure` if MVars are being abstracted.
Fixes#10705
---------
Co-authored-by: Eric Wieser <efw@google.com>
This PR fixes another instance of the “default parameter value in
constructor” footgun, which was affecting the `cases` tactic in the
`grind` interactive mode.
