This PR adds “non-branching case statements”: For each inductive
constructor `T.con` this adds a function `T.con.with` that is similar
`T.casesOn`, but has only one arm (the one for `con`), and an additional
`t.toCtorIdx = 12` assumption.
For example:
```lean
inductive Vec (α : Type) : Nat → Type where
| nil : Vec α 0
| cons {n} : α → Vec α n → Vec α (n + 1)
/--
info: @[reducible] protected def Vec.cons.elim.{u} : {α : Type} →
{motive : (a : Nat) → Vec α a → Sort u} →
{a : Nat} →
(t : Vec α a) →
t.ctorIdx = 1 → ({n : Nat} → (a : α) → (a_1 : Vec α n) → motive (n + 1) (Vec.cons a a_1)) → motive a t
-/
#guard_msgs in
#print sig Vec.cons.elim
```
This is a building block for non-quadratic implementations of `BEq` and
`DecidableEq` etc.
Builds on top of #9951.
The compiled code for a these functions could presumably, without
branching on the inductive value, directly access the fields. Achieving
this optimization (and achieving it without a quadratic compilation
cost) is not in scope for this PR.
Although `HEq` was abbreviated as `≍` in #8503, many instances of the
form `HEq x y` still remain.
Therefore, I searched for occurrences of `HEq x y` using the regular
expression `(?<![A-Za-z/@]|``)HEq(?![A-Za-z.])` and replaced as many as
possible with the form `x ≍ y`.
This PR fixes an issue when including a hard line break in a `Format`
that caused subsequent (ordinary) line breaks to be erroneously
flattened to spaces.
This issue is especially important for displaying notes and hints in
error messages, as these components could appear garbled due to improper
line-break rendering.
This PR introduces a `noConfusionType` construction that’s sub-quadratic
in size, and reduces faster.
The previous `noConfusion` construction with two nested `match`
statements is quadratic in size and reduction behavior. Using some
helper definitions, a linear size construction is possible.
With this, processing the RISC-V-AST definition from
https://github.com/opencompl/sail-riscv-lean takes 6s instead of 60s.
The previous construction is still used when processing the early
prelude, and can be enabled elsewhere using `set_option
backwards.linearNoConfusionType false`.
This PR makes `#guard_msgs` to treat `trace` messages separate from
`info`, `warning` and `error`. It also introduce the ability to say
`#guard_msgs (pass info`, like `(drop info)` so far, and also adds
`(check info)` as the explicit form of `(info)`, for completeness.
Fixes#8266
This PR adds a convenience for inductive predicates in `grind`. Now,
give an inductive predicate `C`, `grind [C]` marks `C` terms as
case-split candidates **and** `C` constructors as E-matching theorems.
Here is an example:
```lean
example {B S T s t} (hcond : B s) : (ifThenElse B S T, s) ==> t → (S, s) ==> t := by
grind [BigStep]
```
Users can still use `grind [cases BigStep]` to only mark `C` as a case
split candidate.
This PR adds "performance" counters (e.g., number of instances per
theorem) to `grind`. The counters are always reported on failures, and
on successes when `set_option diagnostics true`.
This PR fixes a bug in the internalization of offset terms in the
`grind` tactic. For example, `grind` was failing to solve the following
example because of this bug.
```lean
example (f : Nat → Nat) : f (a + 1) = 1 → a = 0 → f 1 = 1 := by
grind
```
This PR fixes a few bugs in the `grind` tactic: missing issues, bad
error messages, incorrect threshold in the canonicalizer, and bug in the
ground pattern internalizer.
This PR introduces a new feature that allows users to specify which
inductive datatypes the `grind` tactic should perform case splits on.
The configuration option `splitIndPred` is now set to `false` by
default. The attribute `[grind cases]` is used to mark inductive
datatypes and predicates that `grind` may case split on during the
search. Additionally, the attribute `[grind cases eager]` can be used to
mark datatypes and predicates for case splitting both during
pre-processing and the search.
Users can also write `grind [HasType]` or `grind [cases HasType]` to
instruct `grind` to perform case splitting on the inductive predicate
`HasType` in a specific instance. Similarly, `grind [-Or]` can be used
to instruct `grind` not to case split on disjunctions.
Co-authored-by: Leonardo de Moura <leodemoura@amazon.com>
This PR improves the diagnostic information provided in `grind` failure
states. We now include the list of issues found during the search, and
all search thresholds that have been reached. This PR also improves its
formatting.
This PR adds support for numerals, lower & upper bounds to the offset
constraint module in the `grind` tactic. `grind` can now solve examples
such as:
```
example (f : Nat → Nat) :
f 2 = a →
b ≤ 1 → b ≥ 1 →
c = b + 1 →
f c = a := by
grind
```
In the example above, the literal `2` and the lower&upper bounds, `b ≤
1` and `b ≥ 1`, are now processed by offset constraint module.
This PR implements support for offset equality constraints in the
`grind` tactic and exhaustive equality propagation for them. The `grind`
tactic can now solve problems such as the following:
```lean
example (f : Nat → Nat) (a b c d e : Nat) :
f (a + 3) = b →
f (c + 1) = d →
c ≤ a + 2 →
a + 1 ≤ e →
e < c →
b = d := by
grind
```
This PR improves the failure message produced by the `grind` tactic. We
now include information about asserted facts, propositions that are
known to be true and false, and equivalence classes.
This PR adds a simple strategy to the (WIP) `grind` tactic. It just
keeps internalizing new theorem instances found by E-matching. The
simple strategy can solve examples such as:
```lean
grind_pattern Array.size_set => Array.set a i v h
grind_pattern Array.get_set_eq => a.set i v h
grind_pattern Array.get_set_ne => (a.set i v hi)[j]
example (as bs : Array α) (v : α)
(i : Nat)
(h₁ : i < as.size)
(h₂ : bs = as.set i v)
: as.size = bs.size := by
grind
example (as bs cs : Array α) (v : α)
(i : Nat)
(h₁ : i < as.size)
(h₂ : bs = as.set i v)
(h₃ : cs = bs)
(h₄ : i ≠ j)
(h₅ : j < cs.size)
(h₆ : j < as.size)
: cs[j] = as[j] := by
grind
opaque R : Nat → Nat → Prop
theorem Rtrans (a b c : Nat) : R a b → R b c → R a c := sorry
grind_pattern Rtrans => R a b, R b c
example : R a b → R b c → R c d → R d e → R a d := by
grind
```
This PR completes the implementation of `addCongrTable` in the (WIP)
`grind` tactic. It also adds a new test to demonstrate why the extra
check is needed. It also updates the field `cgRoot` (congruence root).
This PR adds support for constructors to the (WIP) `grind` tactic. When
merging equivalence classes, `grind` checks for equalities between
constructors. If they are distinct, it closes the goal; if they are the
same, it applies injectivity.
This PR adds support for detecting congruent terms in the (WIP) `grind`
tactic. It also introduces the `grind.debug` option, which, when set to
`true`, checks many invariants after each equivalence class is merged.
This option is intended solely for debugging purposes.
