Module

HenselianLocalRing_of_moduleFinite_of_isLocalRing.lean

Nyll.SchemeTheory.RingTheory.HenselianLocalRing_of_moduleFinite_of_isLocalRing
2 declarations indexed from sourceView source ↗

Henselian Local Ring of module Finite of is Local Ring

Declarations

AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianLocalRing_of_moduleFinite_of_isLocalRing.HensFinAux.main

A finite local algebra over a henselian local ring lifts simple roots of monic polynomials.

Source context 7 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs
namespace HenselianLocalRing_of_moduleFinite_of_isLocalRing
universe u v
namespace HensFinAux
open IsLocalRing Polynomial
open _root_.HenselianLocalRing
  (exists_completeOrthogonalIdempotents_forall_isLocalRing_quotient_of_moduleFinite)
theorem main (R : Type u) [CommRing R] [HenselianLocalRing R]
    {S : Type v} [CommRing S] [IsLocalRing S] [Algebra R S] [Module.Finite R S]
    (f : S[X]) (hf : f.Monic) (a₀ : S) (h₁ : f.eval a₀ ∈ maximalIdeal S)
    (h₂ : IsUnit (f.derivative.eval a₀)) : ∃ a : S, f.IsRoot a ∧ a - a₀ ∈ maximalIdeal S
HenselianLocalRing.of_moduleFinite_of_isLocalRing

A finite local algebra over a henselian local ring is henselian.

Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs
namespace HenselianLocalRing_of_moduleFinite_of_isLocalRing
universe u v
open HensFinAux in
theorem _root_.HenselianLocalRing.of_moduleFinite_of_isLocalRing
    {R : Type u} [CommRing R] [HenselianLocalRing R]
    {S : Type v} [CommRing S] [IsLocalRing S] [Algebra R S] [Module.Finite R S] :
    HenselianLocalRing S