| m1 ≤ # x0, m2 + m ≤ m1, m2 + m ≤ # x0, m1 ≤ m → firstn(0, restn(m1, firstn(m, restn(m2, x0)))) = firstn(0, restn(m2 + m1, x0)), ∀ n0, m0, n, m. n0 + m0 ≤ # x0 ∧ n + m ≤ m0 → firstn(m, restn(n, firstn(m0, restn(n0, x0)))) = firstn(m, restn(n0 + n, x0)) ⊦ firstn(m, restn(m2, firstn(m1, x0))) = firstn(m, restn(m2, x0)) |
⊦ n ≤ # x → (y = firstn(n, x) ∧ z = restn(n, x) ↔ x = y + z ∧ # y = n)
Used simplifier rules: rest-append: ⊦ n + m ≤ # x → restn(n, x + y) = restn(n, x) + y;%first-append-01: ⊦ n + m ≤ # x → firstn(m, restn(n, x) + y) = firstn(m, restn(n, x));%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%c: ⊦ m + n = n + m; from specification nat-basic%a: ⊦ (x + y) + z = x + y + z; from specification list Used terms: x0, m1, y, z