14 lines
276 B
Text
14 lines
276 B
Text
example (f : nat → nat) (a b : nat) : f a = a → f (f a) = a :=
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begin
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intro h₁,
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subst h₁ -- ERROR
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end
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open nat
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example (f : nat → nat) (a b : nat) : f a = a → a = 0 → f (f a) = a :=
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begin
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intro h₁ h₂,
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subst a, -- should use h₂
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rewrite +h₁
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end
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