m < n, m + n < 2 ⊦ n = 0, m = 0 ∧ n = 1
Used simplifier rules: a: ⊦ (m + n0) + n1 = m + n0 + n1;%c: ⊦ m + n = n + m;%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic1