| 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 ⊦ |
⊦ upper-bound(ar, i) ↔ (∀ n, m. n + m ≤ # ar → sum(ar, n, m) ≤ i)
i0 < sum(ar0, n, m), n + m ≤ # ar0, ∀ n, m. (n + m ≤ # ar → sum(ar, n, m) ≤ i) → n + m ≤ # ar0 → sum(ar0, n, m) ≤ i0, ∀ n, m. n + m ≤ # ar → sum(ar, n, m) ≤ i ⊦
Used terms: i, ar