(motive : ℤ → ℤ → Sort u_1) →
  (x x_1 : ℤ) →
    ((m n : ℕ) → motive (Int.ofNat m) (Int.ofNat n)) →
      ((m n : ℕ) → motive (Int.ofNat m) (Int.negSucc n)) →
        ((a : ℕ) → motive (Int.negSucc a) 0) →
          ((m n : ℕ) → motive (Int.negSucc m) (Int.ofNat n.succ)) →
            ((m n : ℕ) → motive (Int.negSucc m) (Int.negSucc n)) → motive x x_1