8 lines
441 B
Text
8 lines
441 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 :=
|
||
fun {α : Type u_1} {β : Type u_2} {f : α → β} (x : β) (x_1 : Imf f x) =>
|
||
match x, x_1 with
|
||
| .(f a), Imf.mk a => a
|
||
theorem ex.{u} : ∀ {α β : Sort u} (h : α = β) (a : α), cast h a ≅ a :=
|
||
fun (x x_1 : Sort u) (x_2 : x = x_1) (x_3 : x) =>
|
||
match x, x_1, x_2, x_3 with
|
||
| α, .(α), Eq.refl α, a => HEq.refl a
|