∀ (motive : (x : ℕ) → Fin2 x → Fin2 x → Sort u_1) (a : ℕ) (a_1 : Fin2 a.succ)
  (h_1 : (n : ℕ) → motive (n + 1) Fin2.fz Fin2.fz) (h_2 : (n : ℕ) → (j : Fin2 n) → motive (n + 1) Fin2.fz j.fs)
  (h_3 : (a : ℕ) → (a_2 : Fin2 a.succ) → motive (a.succ + 1) a_2.fs Fin2.fz)
  (h_4 : (a : ℕ) → (i : Fin2 a.succ) → (j : Fin2 (a + 1)) → motive (a.succ + 1) i.fs j.fs),
  (match a.succ + 1, a_1.fs, Fin2.fz with
    | .(n + 1), Fin2.fz, Fin2.fz => h_1 n
    | .(n + 1), Fin2.fz, j.fs => h_2 n j
    | .(a.succ + 1), a_2.fs, Fin2.fz => h_3 a a_2
    | .(a.succ + 1), i.fs, j.fs => h_4 a i j) =
    h_3 a a_1