| i ≤ j ⊦ count-i2j(i, j) = i ' + count-i2j(i + 1, j) |
i ≤ j, ∀ j0, i0. i→n(j0 - i0) < i→n(j - i) → i0 ≤ j0 → count-i2j(i0, j0) = i0 ' + count-i2j(i0 + 1, j0) ⊦ count-i2j(i, j) = i ' + count-i2j(i + 1, j)
Used simplifier rules: <; (wellfounded) Used terms: i→n(j - i)