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