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