| restn(n -1, (a ' + x0).tail) = [], 0 < n, n ≤ # x0, (∃ n. restn(n, x0) = [] ∧ n < # x0) → x0 = [] ⊦ |
restn(n - 1, x0) = [], n ≤ # x0 ⊦ n = 0, x0 = [], ∃ n. restn(n, x0) = [] ∧ n < # x0
Used simplifier rules: ⊦ m ≤ 0 ↔ m = 0; (s)% ⊦ # [] = 0; (s)% ⊦ 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)