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