| dups(count-i2j(i, i1 + i)), ∀ j0, i0. i→n(j0 - i0) < i→n(i1) → dups(count-i2j(i0, j0)) → false ⊦ |
⊦ i ≤ j → count-i2j(i, j) = count-i2j(i, j - 1) + j
¬ i ≤ i1 + i, dups(count-i2j(i, i1 + i)), ∀ j0, i0. i→n(j0 - i0) < i→n(i1) → dups(count-i2j(i0, j0)) → false ⊦
i ≤ i1 + i, dups(count-i2j(i, i1 + i - 1) + (i1 + i)), ∀ j0, i0. i→n(j0 - i0) < i→n(i1) → dups(count-i2j(i0, j0)) → false ⊦
Used terms: i1 + i, i