{motive : ℕ → ℕ → Sort u_1} →
  motive 0 0 →
    ((n : ℕ) → motive 0 n → motive 0 (n + 1)) →
      ((m : ℕ) → motive m 0 → motive (m + 1) 0) →
        ((m n : ℕ) → motive m n → motive (m + 1) (n + 1)) → (m n : ℕ) → motive m n