Module

SmoothReduced.lean

Nyll.SchemeTheory.RingTheory.SmoothReduced
3 declarations indexed from sourceView source ↗

Reducedness of smooth algebras over fields

The etale generic-fiber argument and local standard-etale presentations prove reducedness directly. This is the reusable ring part of the pinned FLT proof previously maintained in AlgebraicCurves.

Imports4
  • Mathlib.RingTheory.Unramified.LocalStructure
  • Mathlib.RingTheory.Unramified.Field
  • Mathlib.RingTheory.Localization.FractionRing
  • Mathlib.RingTheory.Flat.Basic
Imported by3

Declarations

Algebra.Etale.isReduced_of_field
Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open scoped TensorProduct
namespace Algebra.Etale
theorem _root_.Algebra.Etale.isReduced_of_field
    {K B : Type*} [Field K] [CommRing B] [Algebra K B] [Algebra.Etale K B] :
    IsReduced B
Algebra.Etale.isReduced_of_isDomain

An etale algebra over a domain is reduced, by flat injection into its generic fiber.

Source context 2 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open scoped TensorProduct
theorem Algebra.Etale.isReduced_of_isDomain
    {R B : Type*} [CommRing R] [IsDomain R] [CommRing B] [Algebra R B] [Algebra.Etale R B] :
    IsReduced B
Algebra.Smooth.isReduced_of_field

A smooth algebra over a field is reduced, by its standard-etale local presentations.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open scoped TensorProduct
namespace Algebra.Smooth
theorem _root_.Algebra.Smooth.isReduced_of_field
    {K A : Type*} [Field K] [CommRing A] [Algebra K A] [Algebra.Smooth K A] :
    IsReduced A