English
If α is a principal ideal ring with no zero divisors and nontrivial, then for any P, P is prime iff P = ⊥ or P = span{p} for some prime p.
Русский
Если α — кольцо с главными идеалами без нулевых делителей и ненулевое, то для любого P: Pprime тогда, когда P = ⊥ или P = span{p} для некоторого простого p.
LaTeX
$$$P.IsPrime \\iff P = \\perp \\lor \\exists p, Prime p \\land P = \\operatorname{span}\\{p\\}.$$$
Lean4
theorem isPrime_iff_of_isPrincipalIdealRing_of_noZeroDivisors [NoZeroDivisors α] [Nontrivial α] {P : Ideal α} :
P.IsPrime ↔ P = ⊥ ∨ ∃ p, Prime p ∧ P = span { p } :=
by
rw [or_iff_not_imp_left, ← forall_congr' isPrime_iff_of_isPrincipalIdealRing, ← or_iff_not_imp_left,
or_iff_right_of_imp]
rintro rfl; exact bot_prime