8 lines
357 B
Text
8 lines
357 B
Text
def h.{u_1, u_2} : {α : Type u_1} → {β : Type u_2} → {f : α → β} → {b : β} → Imf f b → α :=
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fun {α} {β} {f} x x_1 =>
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match x, x_1 with
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| .(f a), Imf.mk a => a
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theorem ex.{u} : ∀ {α β : Sort u} (h : α = β) (a : α), cast h a ≅ a :=
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fun x x_1 x_2 x_3 =>
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match x, x_1, x_2, x_3 with
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| α, .(α), Eq.refl α, a => HEq.refl a
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