16 lines
416 B
Text
16 lines
416 B
Text
open tactic
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def f : nat → nat := λ x, x + 10
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@[simp] lemma f_lemma (x : nat) : f x = x + 10 :=
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rfl
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example (p : nat → Prop) (a : nat) (h : p (a + 10)) : p (f a) :=
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by do
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t ← target,
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S ← simp_lemmas.mk_default,
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new_t ← dsimplify (λ e, failed) (λ e, do new_e ← S^.drewrite e, return (new_e, tt)) t,
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expected ← to_expr `(p (a + 10)),
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guard (new_t = expected),
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change new_t,
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assumption
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