m | n, m | n0, n0 < n ⊦ n = 0, m | dist(n, n0)
Used simplifier rules: f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic1%lels-01: ⊦ ¬ m ≤ n ↔ n < m; from specification nat