max(m, n) < n0, n < m, n0 ≤ m, n < n0 ⊦ n0 = 0, m = max(max(m, n), n0), m = 0
n < m, n0 ≤ m, n < n0 ⊦ max(m, n) < n0, n0 = 0, m = max(max(m, n), n0), m = 0
Used formulas: max(m, n) < n0