| n0 +1 ≤ # x, ∀ x, y. n0 ≤ # x → restn(n0, x + y) = restn(n0, x) + y ⊦ restn(n0 +1, x + y) = restn(n0 +1, x) + y |
n0 < # x, ∀ x, y. n0 ≤ # x → restn(n0, x + y) = restn(n0, x) + y ⊦ restn(n0, x.tail + y) = restn(n0, x.tail) + y, x = []
Used simplifier rules: restN-rec: ⊦ restn(n + 1, x) = restn(n, x.tail);%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ x ≠ [] → (x + y).tail = x.tail + y; (s)% ⊦ # x = 0 ↔ x = []; (s)%f: ⊦ m < n → n ≠ 0; (forward) from specification nat-basic% ⊦ m + 1 ≤ n ↔ m < n; (s)%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic% ⊦ m +1 = m + 1; (s)