English
The prime spectrum is in bijection with the set of maximal ideals via a natural equivalence mapping maximal ideals to their corresponding prime ideals and vice versa.
Русский
Спектр простых идеалов устанавливает биекцию с множеством максимальных идеалов через естественное отображение в обе стороны.
LaTeX
$$equivSubtype : MaximalSpectrum R ≃ { I : Ideal R // I.IsMaximal }$$
Lean4
/-- If `S` is `R`-standard smooth of relative dimension zero, it is étale. -/
instance (priority := 900) [IsStandardSmoothOfRelativeDimension 0 R S] : Etale R S
where
finitePresentation := (IsStandardSmoothOfRelativeDimension.isStandardSmooth 0).finitePresentation
formallyEtale :=
have : IsStandardSmooth R S := IsStandardSmoothOfRelativeDimension.isStandardSmooth 0
have : FormallyUnramified R S := ⟨inferInstance⟩
Algebra.FormallyEtale.of_unramified_and_smooth