Module

DepthTwoRegularPair.lean

Nyll.SchemeTheory.RingTheory.DepthTwoRegularPair
1 declaration indexed from sourceView source ↗

Regular pairs in local rings of depth at least two

Declarations

SchemeTheory.exists_regular_pair_of_two_le_depth

Depth at least two supplies two elements of the maximal ideal that are regular in either order.

Source context 2 commands

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

open RingTheory IsLocalRing
namespace SchemeTheory
theorem exists_regular_pair_of_two_le_depth
    (R : Type*) [CommRing R] [IsLocalRing R] [IsNoetherianRing R]
    (hdepth : (2 : ℕ∞) ≤ Module.depth R R) :
    ∃ x ∈ maximalIdeal R, ∃ y ∈ maximalIdeal R,
      Sequence.IsWeaklyRegular R [x, y] ∧ Sequence.IsWeaklyRegular R [y, x]