| n0 + n1 ≤ # x ⊦ firstn(n0 + n1, x) = firstn(n0, x) + sublist(n0, n1, x) |
# y = n0 + n1, x = y + z, n0 + n1 ≤ # x ⊦ y = firstn(n0, x) + sublist(n0, n1, x)
Used simplifier rules: ⊦ n ≤ # x → (y = firstn(n, x) ∧ z = restn(n, x) ↔ x = y + z ∧ # y = n); (elim) Used terms: x, n0 + n1, y, z