| i0 * j + i1 * j + j0 = i2 * j + j1, j0 < i2 * j + j1, i1 ≤ i2 * j + j1, i1 * j + j0 < i2 * j + j1, 0 ≤ i2, 0 ≤ j1, j0 + 1 < i0, i1 < i0, 0 < j, (i1 * j + j0) + 1 < i0, 0 < i0, 1 < j, i1 < i0 * j, i1 * j + j0 < j, j0 < 0, j0 < j, j0 + 1 < j, 0 < j + j0, (i1 * j + j0) + 1 < j, i1 ≤ 0, i1 < j, i1 < j + j0, i1 * j + j0 < 0, (i1 * j + j0) + 1 < i0 * j, j0 + 1 < i0 * j, 0 ≤ i0, j1 < j ⊦ j0 = 0, i0 + i1 = i2 + 1, i2 * j + j1 = (i0 + i1) * j + j0 ∧ j1 < j0 + j, j * i2 + j1 = (i0 + i1) * j + j0 ∧ j0 + j ≤ j1 ∧ j1 < 2 * j + j0 |
⊦ (i + i0) * j = i * j + i0 * j
i0 * j + i1 * j + j0 = i2 * j + j1, j0 < i2 * j + j1, i1 ≤ i2 * j + j1, i1 * j + j0 < i2 * j + j1, 0 ≤ i2, 0 ≤ j1, j0 + 1 < i0, i1 < i0, 0 < j, (i1 * j + j0) + 1 < i0, 0 < i0, 1 < j, i1 < i0 * j, i1 * j + j0 < j, j0 < 0, j0 < j, j0 + 1 < j, 0 < j + j0, (i1 * j + j0) + 1 < j, i1 ≤ 0, i1 < j, i1 < j + j0, i1 * j + j0 < 0, (i1 * j + j0) + 1 < i0 * j, j0 + 1 < i0 * j, 0 ≤ i0, j1 < j ⊦ j0 = 0, i0 + i1 = i2 + 1, i2 * j + j1 = (i0 * j + i1 * j) + j0 ∧ j1 < j0 + j, j * i2 + j1 = (i0 * j + i1 * j) + j0 ∧ j0 + j ≤ j1 ∧ j1 < 2 * j + j0
Used terms: j, i1, i0