⊦ 0 ≤ j ∧ j ≤ i → binom_coef(i, j) = fac(i) / (fac(i - j) * fac(j))
0 ≤ 1 ∧ 1 ≤ i, 0 < i ⊦ fac(i) / (fac(i - 1) * fac(1)) = i
Used simplifier rules: leone: ⊦ 1 ≤ i ↔ 0 < i; from specification int-abs Used terms: 1, i