| (i1 * j + j0) * (i2 * j + j1) = (i1 * i2 * j + i1 * j1 + j0 * i2) * j + j0 * j1, 0 < j, j0 < j, j1 < j, 0 ≤ i2, 0 ≤ j0, 0 ≤ j1, 0 ≤ i1 ⊦ (j0 * j1) % j = ((i1 * j + j0) * (i2 * j + j1)) % j |
j1 < j, j0 < j, 0 < j, 0 ≤ i1, 0 ≤ j1, 0 ≤ j0, 0 ≤ i2 ⊦ (j0 * j1) % j = ((i1 * i2 * j + i1 * j1 + j0 * i2) * j + j0 * j1) % j