| (m + 1) + m0 < # x, n0 ≤ m, ∀ n1, m0, x. n1 + m0 < # x ∧ n0 ≤ n1 → x = [] ∨ firstn(n0, restn(m0, x).rest) ⊑ firstn(n1, restn(m0, x).rest) ⊦ x = [], firstn(n0, restn(m0, x).rest.rest) ⊑ firstn(m, restn(m0, x).rest.rest) |
(m + 1) + m0 < # x, n0 ≤ m, m + m0 < # x ∧ n0 ≤ m → x = [] ∨ firstn(n0, restn(m0, x).rest) ⊑ firstn(m, restn(m0, x).rest), ∀ n1, m0, x. n1 + m0 < # x ∧ n0 ≤ n1 → x = [] ∨ firstn(n0, restn(m0, x).rest) ⊑ firstn(n1, restn(m0, x).rest) ⊦ x = [], firstn(n0, restn(m0, x).rest.rest) ⊑ firstn(m, restn(m0, x).rest.rest)
Used terms: m, m0, x