lean2/tests/lean/hott/619.hlean

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-- HoTT
open is_equiv equiv eq
definition my_rec_on_ua [recursor] {A B : Type} {P : A ≃ B → Type}
(f : A ≃ B) (H : Π(q : A = B), P (equiv_of_eq q)) : P f :=
right_inv equiv_of_eq f ▸ H (ua f)
theorem foo {A B : Type} (f : A ≃ B) : A = B :=
begin
induction f using my_rec_on_ua,
assumption
end