Module

PuncturedHypersurfacePrime.lean

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

Nonclosed points of local hypersurfaces

A principal hypersurface in a Noetherian local ring of dimension at least two contains a prime different from the maximal ideal. The same construction on a prime quotient produces a point on a specified irreducible component.

Imports3
  • Mathlib.RingTheory.Ideal.KrullsHeightTheorem
  • Mathlib.RingTheory.LocalRing.Quotient
  • Mathlib.RingTheory.LocalRing.RingHom.Basic
Imported by3

Declarations

SchemeTheory.exists_prime_containing_ne_maximal_of_two_le_ringKrullDim

A hypersurface in local dimension at least two contains a nonclosed point.

Source context 3 commands

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

open IsLocalRing
namespace SchemeTheory
universe u
theorem exists_prime_containing_ne_maximal_of_two_le_ringKrullDim
    (R : Type u) [CommRing R] [IsLocalRing R] [IsNoetherianRing R]
    (hdim : (2 : WithBot ℕ∞) ≤ ringKrullDim R)
    (f : R) (hf : f ∈ maximalIdeal R) :
    ∃ P : Ideal R, P.IsPrime ∧ f ∈ P ∧ P ≠ maximalIdeal R
SchemeTheory.exists_prime_over_containing_ne_maximal_of_two_le_quotient_ringKrullDim

The hypersurface meets the puncture on every prime quotient of dimension at least two.

Source context 3 commands

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

open IsLocalRing
namespace SchemeTheory
universe u
theorem exists_prime_over_containing_ne_maximal_of_two_le_quotient_ringKrullDim
    (R : Type u) [CommRing R] [IsLocalRing R] [IsNoetherianRing R]
    (P : Ideal R) [P.IsPrime]
    (hdim : (2 : WithBot ℕ∞) ≤ ringKrullDim (R ⧸ P))
    (f : R) (hf : f ∈ maximalIdeal R) :
    ∃ Q : Ideal R, Q.IsPrime ∧ P ≤ Q ∧ f ∈ Q ∧ Q ≠ maximalIdeal R