| j - 1 ≤ i ∧ 0 ≤ j - 1 → fac(i - (j - 1)) * fac(j - 1) | fac(i), 0 ≤ j - 1 ∧ j - 1 ≤ i, 0 ≤ j ∧ j ≤ i, j ≤ i, 0 < j, 0 < i ⊦ (fac(i) / (fac(i - j) * fac(j)) - fac(i) / (fac(i - (j - 1)) * fac(j - 1))) * fac(j) * fac(i + 1 - j) = fac(i) * (i + 1 - 2 * j) |
⊦ i ≤ j ∧ 0 ≤ i → fac(j - i) * fac(i) | fac(j)
j ≤ i ∧ 0 ≤ j → fac(i - j) * fac(j) | fac(i), j - 1 ≤ i ∧ 0 ≤ j - 1 → fac(i - (j - 1)) * fac(j - 1) | fac(i), 0 ≤ j - 1 ∧ j - 1 ≤ i, 0 ≤ j ∧ j ≤ i, j ≤ i, 0 < j, 0 < i ⊦ (fac(i) / (fac(i - j) * fac(j)) - fac(i) / (fac(i - (j - 1)) * fac(j - 1))) * fac(j) * fac(i + 1 - j) = fac(i) * (i + 1 - 2 * j)
Used terms: j, i