m2 < m1 ⊦ m2 * m + n ≤ m1 * m + n0 ↔ n ≤ (m1 - m2) * m + n0
Used simplifier rules: ⊦ m < n → n ≠ 0; (s)%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic