∀ {α : Type u} (xs xs_1 : Array α) (e_xs : xs = xs_1) (ys ys_1 : Array α) (e_ys : ys = ys_1) (hsz : xs.size = ys.size)
  (p p_1 : α → α → Bool),
  p = p_1 → ∀ (i i_1 : ℕ) (e_i : i = i_1) (x : i ≤ xs.size), xs.isEqvAux ys hsz p i x = xs_1.isEqvAux ys_1 ⋯ p_1 i_1 ⋯