29 lines
475 B
Text
29 lines
475 B
Text
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open nat
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definition id [unfold-f] {A : Type} (a : A) := a
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definition compose {A B C : Type} (g : B → C) (f : A → B) (a : A) := g (f a)
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notation g ∘ f := compose g f
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example (a b : nat) (H : a = b) : id a = b :=
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begin
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esimp,
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state,
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exact H
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end
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example (a b : nat) (H : a = b) : (id ∘ id) a = b :=
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begin
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esimp,
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state,
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exact H
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end
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attribute compose [unfold-f]
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example (a b : nat) (H : a = b) : (id ∘ id) a = b :=
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begin
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esimp,
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state,
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exact H
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end
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