| n < # x + # x0 ⊦ (x + x0)[n] = (n < # x ⊃ x[n];(n < # x0 + # x ⊃ x0[n - # x];nf(n - # x - # x0))) |
n < # x + # x0 ⊦ (x + x0)[n] = (n < # x ⊃ x[n];x0[n - # x]), # x + # x0 = 0
Used simplifier rules: f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic1%c: ⊦ m + n = n + m; from specification nat-basic2