∀ {α : Type u_3} {β : Type u_1} (motive : α → List β → Sort u_2) (x : α) (x_1 : List β) (h_1 : (a : α) → motive a [])
  (h_2 : (a : α) → (b : β) → (l : List β) → motive a (b :: l)) (a : α),
  x = a →
    x_1 = [] →
      (match x, x_1 with
        | a, [] => h_1 a
        | a, b :: l => h_2 a b l) ≍
        h_1 a