| fac(i - j) * j * fac(j - 1) | fac(i) ∧ fac(i - j) * j * fac(j - 1) ≠ 0, 0 < j, 0 < i, 0 < j, j ≤ i, 0 ≤ j, 0 ≤ i ⊦ i * fac(i - 1) / (fac(i - j) * fac(j - 1)) = (fac(i) * j) / (fac(i - j) * 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))
Used simplifier rules: fac-not-zero: ⊦ fac(i) * fac(j) ≠ 0;%fac-zero: ⊦ i ≤ 0 → fac(i) = 1;%fac-zero-02: ⊦ fac(i) ≠ 0;%zero-neq-01: ⊦ 0 < i → (i * j = 0 ↔ j = 0); from specification int-mult%zero-eq: ⊦ i * j = 0 ↔ i = 0 ∨ j = 0; from specification int-mult%div-mult-01: j ≠ 0, i0 ≠ 0 ⊦ (i * i0) / (j * i0) = i / j; from specification int-div%Mult-zero: ⊦ i * 0 = 0; from specification int-mult%sub-zero-01: ⊦ i - 0 = i; from specification int-abs%commutativity: ⊦ i * j = j * i; from specification int-mult%associativity: ⊦ i * j * j0 = (i * j) * j0; from specification int-mult