j ≤ i ∧ 0 < j ∧ 0 < i, ∀ i0, j. i→n(i0) < i→n(i) → j ≤ i0 ∧ 0 < j ∧ 0 < i0 → fac(j) * fac(i0 - j) | fac(i0) ⊦ fac(j) * fac(i - j) | fac(i)
Used simplifier rules: <; (wellfounded) Used terms: i→n(i)