| n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ x0 = [], restn(n - 1, x0).last = x0.last, n = 0 |
n = m + 1, n ≤ # x0, ∀ n. n < # x0 → restn(n, x0).last = x0.last ⊦ x0 = [], restn(m, x0).last = x0.last, n = 0
Used simplifier rules: n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: n, m