rfl
case pos
α β : Type
inst✝ : DecidableEq α
f g : α → β
x : α
h1 : f x = g x
xs_hd : α
xs_tl : List α
xs_ih : ∀ (ys : List α), updateListITE f xs_tl (List.map f ys) x = updateListITE g xs_tl (List.map f ys) x
ys_hd : α
ys_tl : List α
h✝ : x = xs_hd
⊢ f ys_hd = f ys_hd
no goals