21 lines
462 B
Text
21 lines
462 B
Text
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import data.nat
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open nat
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inductive functor (A B : Type) :=
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mk : (A → B) → functor A B
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definition functor.to_fun [coercion] {A B : Type} (f : functor A B) : A → B :=
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functor.rec (λ f, f) f
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inductive struct :=
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mk : Π (A : Type), (A → A → Prop) → struct
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definition struct.to_sort [coercion] (s : struct) : Type :=
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struct.rec (λA r, A) s
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definition g (f : nat → nat) (a : nat) := f a
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check
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λ f,
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(g f 0) = 0 ∧ (functor.to_fun f) 0 = 0
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