| n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ restn(n, a ' + x0).last = x0.last, x0 = [] |
⊦ 0 < n → restn(n, x) = restn(n -1, x.tail)
0 < n, n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ restn(n -1, (a ' + x0).tail).last = x0.last, x0 = []
Used simplifier rules: restN-zero: ⊦ restn(0, x) = x;% ⊦ 0 < n ↔ n ≠ 0; (s)% ⊦ x ≠ [] → (a ' + x).last = x.last; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list Used terms: a ' + x0, n