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