23 lines
487 B
Text
23 lines
487 B
Text
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open equiv
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constants (A B : Type₀) (f : A → B) (g : B → A) (p : Πb, f (g b) = b) (q : Πa, g (f a) = a)
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definition e [constructor] : A ≃ B :=
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equiv.MK f g p q
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example (b : B) : g (f (g b)) = g b :=
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by rewrite [to_right_inv e b]
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example (b : B) : g (f (g b)) = g b :=
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by xrewrite [to_right_inv e b]
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example (b : B) : g (f (g b)) = g b :=
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by krewrite [to_right_inv e b]
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example (b : B) : g (f (g b)) = g b :=
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begin
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let H := to_right_inv e b,
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esimp at H,
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rewrite H
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end
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