| 0 < j, 0 < j, 0 ≤ i1, ∀ i0, j. i→n(i0) < i→n(i1 + 1) → 0 < i0 ∧ 0 < j → (fac(i0) ≤ fac(j) ↔ i0 ≤ j) ⊦ (i1 + 1) * fac(i1) ≤ j * fac(j - 1) ↔ i1 < j |
j = i2 + 1, 0 < j, 0 < j, 0 ≤ i1, ∀ i0, j. i→n(i0) < i→n(i1 + 1) → 0 < i0 ∧ 0 < j → (fac(i0) ≤ fac(j) ↔ i0 ≤ j) ⊦ (i1 + 1) * fac(i1) ≤ j * fac(i2) ↔ i1 < j
Used simplifier rules: ⊦ i0 = i - j ↔ i = i0 + j; (elim) Used terms: j, 1, i