(motive : (x : ℕ) → TypeVec.{u_1} x → TypeVec.{u_1} x → Fin2 x → Sort u_2) →
  (x : ℕ) →
    (x_1 x_2 : TypeVec.{u_1} x) →
      (x_3 : Fin2 x) →
        ((n : ℕ) → (α β : TypeVec.{u_1} n.succ) → (i : Fin2 n) → motive n.succ α β i.fs) →
          ((n : ℕ) → (x x_4 : TypeVec.{u_1} n.succ) → motive n.succ x x_4 Fin2.fz) → motive x x_1 x_2 x_3