20 lines
622 B
Text
20 lines
622 B
Text
module
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/-!
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This is a `grind` regression reported by David Renshaw:
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the following proof works in v4.22.0 but not in v4.23.0-rc2. (Increasing the splits threshold does not help.)
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**Cause:** `Nat.sub` embedding into `Int`.
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**Remark:** The benchmark is nonlinear.
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-/
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example (k m : Nat) (c : Nat → Nat)
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(hk₀ : k ≤ m)
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(h₅₀ : ∀ (a b : Nat), c a - c b = (a - b) * (a + b + 1))
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(x : Nat) : c k ≤ c (m + x) := by
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grind
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example (k m : Nat) (c : Nat → Nat)
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(hk₀ : k ≤ m)
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(h₅₀ : ∀ (a b : Nat), c a - c b = (a - b) * (a + b + 1))
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(x : Nat) : c k ≤ c (m + x) := by
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grind -ring
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