⊦ prime(n) ↔ n ≠ 0 ∧ n ≠ 1 ∧ (∀ m. 2 ≤ m ∧ prime(m) ∧ m * m ≤ n → n % m ≠ 0)
Used simplifier rules: one: ⊦ 1 < m ↔ ¬(m = 0 ∨ m = 1); from specification nat-basic1