| (j1 + j2) % 2 = 0, 2 * i = j1 ^2 + j2 ^2 ⊦ (j1 - j2) % 2 = 0, i = ((j1 - j2) / 2)^2 + ((j1 + j2) / 2)^2 |
j ≠ 0 ⊦ i % j = 0 ↔ (∃ j0. i = j0 * j)
2 ≠ 0, ∃ j0. j1 + j2 = j0 * 2, 2 * i = j1 ^2 + j2 ^2 ⊦ (j1 - j2) % 2 = 0, i = ((j1 - j2) / 2)^2 + ((j1 + j2) / 2)^2
Used terms: 2, j1 + j2