| 2 * (j0 + i0 * j) = (2 * i0 + 1) * j + (2 * j0 - j), 2 * (j0 + i0 * j) = i1 * j + j1, j1 < 2 * j0, j ≤ 2 * j0, 0 ≤ i1, 0 ≤ j1, 0 ≤ i0, 0 ≤ j0, 1 + 2 * i0 < i1, j0 < j, j1 < j, 1 < j, 0 < j, 0 < j0 ⊦ |
(2 * i0 + 1) * j + (2 * j0 - j) = i1 * j + j1, j1 < 2 * j0, j ≤ 2 * j0, 0 ≤ i1, 0 ≤ j1, 0 ≤ i0, 0 ≤ j0, 1 + 2 * i0 < i1, j0 < j, j1 < j, 1 < j, 0 < j, 0 < j0 ⊦