ext n
α β α' β' : Type
γ : β → Type
x y : ℕ → Bool
⊢ xorSeq x y =
    propagate Empty.elim (fun x y => (Empty.elim, _root_.xor (y true) (y false))) fun b => bif b then x else y
case h
α β α' β' : Type
γ : β → Type
x y : ℕ → Bool
n : ℕ
⊢ xorSeq x y n =
    propagate Empty.elim (fun x y => (Empty.elim, _root_.xor (y true) (y false))) (fun b => bif b then x else y) n