Module

HenselianLocalRing_exists_completeOrthogonalIdempotents_forall_isLocalRing_quotient_of_moduleFinite.lean

Nyll.SchemeTheory.RingTheory.HenselianLocalRing_exists_completeOrthogonalIdempotents_forall_isLocalRing_quotient_of_moduleFinite
9 declarations indexed from sourceView source ↗

Henselian Local Ring exists complete Orthogonal Idempotents forall is Local Ring quotient

of module Finite

Declarations

AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_comap_map_mk
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_comap_map_mk {S : Type v} [CommRing S] {K m : Ideal S} (hK : K ≤ m) :
    (m.map (Ideal.Quotient.mk K)).comap (Ideal.Quotient.mk K) = m
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_isMaximal_map_mk
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_isMaximal_map_mk {S : Type v} [CommRing S] {K m : Ideal S} (hm : m.IsMaximal)
    (hK : K ≤ m) : (m.map (Ideal.Quotient.mk K)).IsMaximal
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_map_maximalIdeal_le
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_map_maximalIdeal_le {R : Type u} [CommRing R] [IsLocalRing R]
    {S : Type v} [CommRing S] [Algebra R S] [Module.Finite R S] (m : Ideal S) (hm : m.IsMaximal) :
    (maximalIdeal R).map (algebraMap R S) ≤ m
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_isArtinianRing_fibre
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_isArtinianRing_fibre {R : Type u} [CommRing R] [IsLocalRing R]
    {S : Type v} [CommRing S] [Algebra R S] [Module.Finite R S] :
    IsArtinianRing (S ⧸ (maximalIdeal R).map (algebraMap R S))
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_finite_maximalSpectrum
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_finite_maximalSpectrum {R : Type u} [CommRing R] [IsLocalRing R]
    {S : Type v} [CommRing S] [Algebra R S] [Module.Finite R S] : Finite (MaximalSpectrum S)
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_isIdempotentElem_eq_zero_or_one
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_isIdempotentElem_eq_zero_or_one {R : Type u} [CommRing R] [IsLocalRing R] {a : R}
    (ha : IsIdempotentElem a) : a = 0 ∨ a = 1
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_isIdempotentElem_eq_of_mk_eq
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_isIdempotentElem_eq_of_mk_eq {R : Type u} [CommRing R] [HenselianLocalRing R]
    {S : Type v} [CommRing S] [Algebra R S] [Module.Finite R S] {a b : S}
    (ha : IsIdempotentElem a) (hb : IsIdempotentElem b)
    (h : Ideal.Quotient.mk ((maximalIdeal R).map (algebraMap R S)) a =
      Ideal.Quotient.mk ((maximalIdeal R).map (algebraMap R S)) b) : a = b
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents.hensSplit_isLocalRing_quotient
Source context 5 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
section hensSplitHelpers
open IsLocalRing
theorem hensSplit_isLocalRing_quotient {S : Type v} [CommRing S] (e : S) (m : Ideal S) (hm :
  m.IsMaximal)
    (h1 : 1 - e ∈ m) (h2 : ∀ m' : Ideal S, m'.IsMaximal → m' ≠ m → e ∈ m') :
    IsLocalRing (S ⧸ Ideal.span {1 - e})
HenselianLocalRing.exists_completeOrthogonalIdempotents_forall_isLocalRing_quotient_of_moduleFinite
Source context 4 commands

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

section ProofImplementation
namespace HenselianLocalRing
open _root_.AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.HenselianOrthogonalIdempotents
universe u v
theorem exists_completeOrthogonalIdempotents_forall_isLocalRing_quotient_of_moduleFinite
    {R : Type u} [CommRing R] [HenselianLocalRing R]
    {S : Type v} [CommRing S] [Algebra R S] [Module.Finite R S] :
    ∃ (_ : Fintype (MaximalSpectrum S)) (e : MaximalSpectrum S → S),
      CompleteOrthogonalIdempotents e ∧
      (∀ m : MaximalSpectrum S, e m ∉ m.asIdeal) ∧
      (∀ m m' : MaximalSpectrum S, m ≠ m' → e m ∈ m'.asIdeal) ∧
      (∀ m : MaximalSpectrum S, IsLocalRing (S ⧸ Ideal.span {1 - e m}))