13 lines
219 B
Text
13 lines
219 B
Text
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import data.nat
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open nat
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constant f : nat → nat
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constant g : nat → nat
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definition lemma1 [forward] : ∀ x, g (f x) = x :=
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sorry
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set_option blast.ematch true
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example (a b : nat) : f a = f b → a = b :=
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by blast
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