English
For any prime I ⊆ R, the ideal I × ⊤ is prime in R × S.
Русский
Для любого простого I в R, I × ⊤ простый в R × S.
LaTeX
$$$\\text{isPrime_ideal_prod_top}(I) : (\\mathrm{prod}\\, I \\; (\\top)) \\text{IsPrime}$$$
Lean4
theorem isPrime_of_isPrime_prod_top' {I : Ideal S} (h : (Ideal.prod (⊤ : Ideal R) I).IsPrime) : I.IsPrime :=
by
apply isPrime_of_isPrime_prod_top (S := R)
rw [← map_prodComm_prod]
-- Note: couldn't synthesize the right instances without the `R` and `S` hints
exact map_isPrime_of_equiv (RingEquiv.prodComm (R := R) (S := S))