| 0 < i, 0 < j, j ≤ i, 0 ≤ j, 0 ≤ i ⊦ i * fac(i - 1) / (fac(i - j) * fac(j - 1)) = j * fac(i) / (fac(j) * fac(i - j)), fac(j) * fac(i - j) | fac(i) |
⊦ i ≤ j ∧ 0 ≤ i → fac(j - i) * fac(i) | fac(j)
Used simplifier rules: zero-gels-04: ⊦ i ≤ 0 ∧ 0 ≤ j → i ≤ j; from specification int-abs%commutativity: ⊦ i * j = j * i; from specification int-mult Used terms: j, i