ea10bdf154
This PR improves the case-split heuristics in `grind`. In this PR, we do not increment the number of case splits in the first case. The idea is to leverage non-chronological backtracking: if the first case is solved using a proof that doesn't depend on the case hypothesis, we backtrack and close the original goal directly. In this scenario, the case-split was "free", it didn't contribute to the proof. By not counting it, we allow deeper exploration when case-splits turn out to be irrelevant. The new heuristic addresses the second example in #11545
5 lines
202 B
Text
5 lines
202 B
Text
example (a b : Nat) (f g : Nat → Nat)
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(hf : (∀ i ≤ a, f i ≤ f (i + 1)) ∧ f 0 = 0)
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(hg : (∀ i ≤ b, g i ≤ g (i + 1)) ∧ g 0 = 0 ∧ g b = 0) :
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g (a + b - a) = 0 := by
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grind
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