| j % 2 = 0, i0 < 0, ~1 ≤ i0 + j ⊦ ((i0 + 1) + j) / 2 = i0 / 2 + j / 2 |
⊦ 0 < j ∧ 0 ≤ i → (i0 = i / j ∧ j0 = i % j ↔ i = i0 * j + j0 ∧ 0 ≤ j0 ∧ j0 < j)
j % 2 = 0, i0 < 0, ~1 ≤ i0 + j ⊦ ((i0 + 1) + j) / 2 = i0 / 2 + j / 2, 0 < 2 ∧ 0 ≤ j
j = i1 * 2 + j0, j0 = 0, i0 < 0, j0 < 2, 0 < 2, ~1 ≤ i0 + j, 0 ≤ j0, 0 ≤ j ⊦ ((i0 + 1) + j) / 2 = i0 / 2 + i1
Used terms: j, 2, i, j0