| n < m ⊦ m = 0, m0 ≠ n0 ∧ ¬ n0 < m0, n + n0 ≠ m + m0 ∧ ¬ m + m0 < n + n0 |
⊦ m < m0 ∧ n < n0 → (m + n < m0 + n0 ↔ true)
n < m, n < m ∧ n0 < m0 → (n + n0 < m + m0 ↔ true) ⊦ m = 0, n + n0 ≠ m + m0 ∧ ¬ m + m0 < n + n0, m0 ≠ n0 ∧ ¬ n0 < m0
Used terms: n, m, n0, m0