16bc6ebcb6
This PR ensures that `simp` and `dsimp` do not unfold definitions that are not intended to be unfolded by the user. See issue #5755 for an example affected by this issue. Closes #5755 --------- Co-authored-by: Kim Morrison <kim@tqft.net>
49 lines
932 B
Text
49 lines
932 B
Text
inductive C : Type where
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| C1 (b : Bool) : C
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| C2 (c1 c2 : C) : C
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deriving Inhabited
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open C
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def id1 (b : Bool) : C := C1 b
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def id2 (c : C) : C :=
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match c with
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| C1 b => id1 b
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| C2 c1 c2 => C2 (id2 c1) (id2 c2)
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theorem id2_is_idempotent : id2 (id2 c) ≠ id2 c :=
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match c with
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| C1 b => by
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guard_target =ₛ id2 (id2 (C1 b)) ≠ id2 (C1 b)
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dsimp only [id2]
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guard_target =ₛ id2 (id1 b) ≠ id1 b
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sorry
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| C2 _ _ => by
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sorry
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example : id2 (id1 b) ≠ a := by
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fail_if_success dsimp only [id2]
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dsimp only [id2, id1]
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guard_target =ₛ C1 b ≠ a
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sorry
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/-
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Here is another problematic example that has been fixed.
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-/
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def f : Nat → Nat
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| 0 => 1
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| x+1 => 2 * f x
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def fib : Nat → Nat
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| 0 => 1
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| 1 => 1
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| x+2 => fib (x+1) + fib x
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example : 0 + f (fib 10000) = a := by
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simp [f] -- should not trigger max rec depth
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guard_target =ₛ f (fib 10000) = a
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sorry
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