⊦ prime(j) ↔ 2 ≤ j ∧ (∀ i. 1 < i ∧ i < j → ¬ i | j)
2 ≤ i * j ∧ (∀ i0. 1 < i0 ∧ i0 < i * j → ¬ i0 | i * j), 0 < i, 1 < i, 0 < j, 1 < j ⊦
Used terms: i * j