⊦ n ≠ 0 → (n0 = n -1 ↔ n = n0 +1)
Used simplifier rules: succ: ⊦ m +1 = m + 1;%l: ⊦ m + n < m + n0 ↔ n < n0;%a: ⊦ (m + n0) + n1 = m + n0 + n1;%c: ⊦ m + n = n + m; Used terms: n0, n1