| n ≤ # x ⊦ x + y from n = (x from n) + y |
n ≤ #(a + x0), ∀ n, y. n ≤ # x0 → x0 + y from n = (x0 from n) + y ⊦ (a + x0) + y from n = (a + x0 from n) + y
Used simplifier rules: from-zero-l: ⊦ x from 0 = x;%list freely generated by [], +;;% ⊦ [] + x = x; (s)%a: ⊦ (x + y) + z = x + y + z; from specification list% ⊦ # [] = 0; (s)% ⊦ m ≤ 0 ↔ m = 0; (s)