∀ {α : Type u_1} {β : Type u_2} {γ : Type u_3} {δ : Type u_4} {n : ℕ} {as : Vector α n} {bs : Vector β n}
  {g : γ → δ → δ} {f : α → β → γ} {i : δ},
  Vector.foldr g i (Vector.zipWith f as bs) = Vector.foldr (fun p r => g (f p.1 p.2) r) i (as.zip bs)