∀ {R : Type u_1} {A : Type u_2} [inst : CommRing R] [inst_1 : CommRing A] [inst_2 : Algebra R A]
  [Algebra.FinitePresentation R A] {f : A},
  ↑(PrimeSpectrum.basicOpen f) ⊆ Algebra.smoothLocus R A ↔ Algebra.Smooth R (Localization.Away f)