n1 < m, n1 ≤ m - 1 → (n0 = m - 1 - n1 ↔ m - 1 = n0 + n1) ⊦ n0 = m - n1 + 1 ↔ m = n0 + n1 + 1, m = 0
Used terms: m - 1, n0