| a ∈ restn(n0, y), n0 ≤ # y, ∀ a, x. a ∈ restn(n0, x) ∧ n0 ≤ # x → a ∈ x ⊦ a = a0, a ∈ y |
⊦ n ≤ # x → (y = firstn(n, x) ∧ z = restn(n, x) ↔ x = y + z ∧ # y = n)
Used simplifier rules: ⊦ #(x + y) = # x + # y; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ m ≤ m + n; (s)%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic%c: ⊦ m + n = n + m; from specification nat-basic% ⊦ a ∈ y → a ∈ x + y; (s) Used terms: y, n0, y0, z