| upper-bound(ar, i), ∀ n, m. (n + m ≤ # ar → sum(ar, n, m) ≤ i) → n + m ≤ # ar0 → sum(ar0, n, m) ≤ i0 ⊦ ∀ n, m. n + m ≤ # ar0 → sum(ar0, n, m) ≤ i0 |
i0 < sum(ar0, n, m), upper-bound(ar, i), n + m ≤ # ar0, ∀ n, m. (n + m ≤ # ar → sum(ar, n, m) ≤ i) → n + m ≤ # ar0 → sum(ar0, n, m) ≤ i0 ⊦
Used simplifier rules: ⊦ i ≤ j ↔ ¬ j < i; (ss)