Module

ModuleDepthBound.lean

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

Bounding module depth by Krull dimension

The depth of a nontrivial finite module over a Noetherian local ring is bounded by the Krull dimension of its support and hence by the Krull dimension of the ring.

Imports6
  • Nyll.SchemeTheory.RingTheory.LocalAlgebra
  • Mathlib.RingTheory.KrullDimension.Basic
  • Mathlib.RingTheory.KrullDimension.NonZeroDivisors
  • Mathlib.RingTheory.Support
  • Mathlib.RingTheory.Regular.RegularSequence
  • Mathlib.RingTheory.Ideal.Quotient.Operations
Imported by3

Declarations

AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.Module_depth_le_ringKrullDim.Module.depth_le_krullDim_support'
Source context 8 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.Module_depth_le_ringKrullDim
open IsLocalRing RingTheory
namespace Module
open _root_.Module
open _root_.Module
variable (R M : Type*) [CommRing R] [IsLocalRing R] [AddCommGroup M] [Module R M]
open scoped Pointwise in
lemma depth_le_krullDim_support' [Nontrivial M] [Module.Finite R M] :
    .some (Module.depth R M) ≤ Order.krullDim (Module.support R M)
AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.Module_depth_le_ringKrullDim.Module.depth_le_dim_annihilator'
Source context 7 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.Module_depth_le_ringKrullDim
open IsLocalRing RingTheory
namespace Module
open _root_.Module
open _root_.Module
variable (R M : Type*) [CommRing R] [IsLocalRing R] [AddCommGroup M] [Module R M]
lemma depth_le_dim_annihilator' [Nontrivial M] [Module.Finite R M] :
    .some (Module.depth R M) ≤ ringKrullDim (R ⧸ Module.annihilator R M)
Module.depth_le_ringKrullDim
Source context 3 commands

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

section ProofImplementation
namespace AlgebraicCurves.Foundations.CommutativeAlgebra.Proofs.Module_depth_le_ringKrullDim
open IsLocalRing RingTheory
theorem _root_.Module.depth_le_ringKrullDim {R M : Type*} [CommRing R] [IsLocalRing R]
    [AddCommGroup M] [Module R M] [Nontrivial M] [Module.Finite R M] :
    .some (Module.depth R M) ≤ ringKrullDim R