English
In a cancellative commutative monoid with zero and with subsingleton units, for primes p and q, p divides q if and only if p equals q.
Русский
В моноиде c нулём, с единицами, образующими подмножество, простые p,q: p делит q тогда и только если p = q.
LaTeX
$$$$\forall p,q \in M,\ \mathrm{Prime}(p) \land \mathrm{Prime}(q) \Rightarrow p \mid q \iff p = q.$$$$
Lean4
theorem prime_dvd_prime_iff_eq {M : Type*} [CancelCommMonoidWithZero M] [Subsingleton Mˣ] {p q : M} (pp : Prime p)
(qp : Prime q) : p ∣ q ↔ p = q := by rw [pp.dvd_prime_iff_associated qp, ← associated_eq_eq]