| m0 + n0 + n1 < m + n, m ≤ m0, n ≤ n0 ⊦ m + n = 0 |
m + n ≤ m0 + n, m0 + n0 + n1 < m + n, m ≤ m0, n ≤ n0 ⊦ m + n = 0
Used simplifier rules: lep-02: ⊦ m + n ≤ m + n0 ↔ n ≤ n0;%lels-01: ⊦ ¬ m ≤ n ↔ n < m;%le-ls-simp: ⊦ m ≤ n → (n < m ↔ false);%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%c: ⊦ m + n = n + m; from specification nat-basic2 Used formulas: m + n ≤ m0 + n