English
If p divides q and both are irreducible, then q divides p.
Русский
Если p делит q, и оба несводимы, тогда q делит p.
LaTeX
$$p \mid q \Rightarrow q \mid p$$
Lean4
/-- If `p` and `q` are irreducible, then `p ∣ q` implies `q ∣ p`. -/
theorem dvd_symm [Monoid M] {p q : M} (hp : Irreducible p) (hq : Irreducible q) : p ∣ q → q ∣ p :=
by
rintro ⟨q', rfl⟩
rw [IsUnit.mul_right_dvd (Or.resolve_left (of_irreducible_mul hq) hp.not_isUnit)]