| ¬(fac(j - 1) * fac(i - j) | fac(i - 1) ∧ fac(j - 1) * fac(i - j) ≠ 0), fac(i - j) * j * fac(j - 1) | fac(i), 0 < i, 0 < j, j ≤ i, 0 ≤ j, 0 ≤ i ⊦ i * fac(i - 1) / (fac(i - j) * fac(j - 1)) = fac(i) / (fac(i - j) * fac(j - 1)) |
fac(i - j) * j * fac(j - 1) | fac(i), 0 < i, 0 < j, j ≤ i, 0 ≤ j, 0 ≤ i ⊦ i * fac(i - 1) / (fac(i - j) * fac(j - 1)) = fac(i) / (fac(i - j) * fac(j - 1)), fac(j - 1) * fac(i - j) | fac(i - 1)
Used simplifier rules: fac-not-zero: ⊦ fac(i) * fac(j) ≠ 0;%commutativity: ⊦ i * j = j * i; from specification int-mult%associativity: ⊦ i * j * j0 = (i * j) * j0; from specification int-mult