30 lines
594 B
Text
30 lines
594 B
Text
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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variable f : functor nat nat
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check g (functor.to_fun f) 0
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check g f 0
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definition id (A : Type) (a : A) := a
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variable S : struct
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variable a : S
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check id (struct.to_sort S) a
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check id S a
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