English
Every finitely generated R-algebra is Alg-equivalent to the evaluation of some FGAlgCatSkeleton, i.e., A ≅ P.eval.obj for some skeleton P.
Русский
Каждая конечно порожденная R-алгебра эквивалентна по Alg-эквивалентности вычислению некого FGAlgCatSkeleton: A ≅ P.eval.obj.
LaTeX
$$$\exists P\; \bigl(A \simeq_R P.\text{eval.obj}\bigr)$$$
Lean4
theorem exists_fgAlgCatSkeleton (A : Type v) [CommRing A] [Algebra R A] [h : Algebra.FiniteType R A] :
∃ (P : FGAlgCatSkeleton R), Nonempty (A ≃ₐ[R] P.eval.obj) :=
by
obtain ⟨n, f, hf⟩ := Algebra.FiniteType.iff_quotient_mvPolynomial''.mp h
exact ⟨⟨n, RingHom.ker f⟩, ⟨(Ideal.quotientKerAlgEquivOfSurjective hf).symm⟩⟩