m0 = n ∨ ¬ m0 < n ⊦ (m0 + 1) + 0 -1 = n, n ≠ m0 + 1 ∧ ¬ m0 + 1 < n
Used simplifier rules: z-02: ⊦ 0 + m = m;%a: ⊦ (m + n0) + n1 = m + n0 + n1;%c: ⊦ m + n = n + m;