| 0 < n, n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ x0 = [], restn(n -1, (a ' + x0).rest).last = x0.last |
n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ x0 = [], restn(n - 1, x0).last = x0.last, n = 0
Used simplifier rules: zero: ⊦ 0 < m ↔ m ≠ 0; from specification nat-basic1%a: ⊦ (x + y) + z = x + y + z; from specification list%c-07: ⊦ (a ' + x).rest = x; from specification list%pred-03: ⊦ n -1 = n - 1; from specification nat