contradiction
α β : Type
inst✝ : DecidableEq α
f g : α → β
v xs_hd : α
xs_tl : List α
xs_ih : ∀ (ys : List β), v ∈ xs_tl → xs_tl.length = ys.length → updateListITE f xs_tl ys v = updateListITE g xs_tl ys v
h1 : v = xs_hd ∨ v ∈ xs_tl
h2 : (xs_hd :: xs_tl).length = [].length
⊢ updateListITE f (xs_hd :: xs_tl) [] v = updateListITE g (xs_hd :: xs_tl) [] v
no goals