Module

TruncatedFoxSequence.lean

Nyll.ProCGroups.GolodShafarevich.TruncatedFoxSequence
4 declarations indexed from sourceView source ↗

Right exactness of the truncated mod-p Fox sequence

Strict lifting for the filtered Fox complex and the augmentation-ideal description of the boundary range give a concrete right-exact sequence on shifted finite truncations.

Declarations

ClassFieldTower.ProP.presentationModPTruncatedRelationBoundary_exact

Strict filtered lifting makes the induced relation--boundary pair exact.

Source context 10 commands

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

namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
noncomputable section
universe u
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
theorem presentationModPTruncatedRelationBoundary_exact
    (P : FiniteProPPresentation p d r sourceData G)
    (ν : Fin r → ℕ)
    (hν : ∀ j, P.RelatorZassenhausDepthAtLeast (ν j) j)
    (N : ℕ) :
    Function.Exact (presentationModPTruncatedRelationMap P ν hν N)
      (presentationModPTruncatedFoxBoundary P N)
ClassFieldTower.ProP.presentationModPTruncatedBoundaryAugmentation_exact

Tail equality identifies the induced boundary kernel with its range.

Source context 10 commands

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

namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
noncomputable section
universe u
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
theorem presentationModPTruncatedBoundaryAugmentation_exact
    (P : FiniteProPPresentation p d r sourceData G) (N : ℕ) :
    Function.Exact (presentationModPTruncatedFoxBoundary P N)
      (presentationModPTruncatedAugmentation (p := p) (G := G) N)
ClassFieldTower.ProP.presentationModPTruncatedAugmentation_surjective

The induced augmentation is surjective.

Source context 11 commands

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

namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
noncomputable section
universe u
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
omit [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G] in
theorem presentationModPTruncatedAugmentation_surjective (N : ℕ) :
    Function.Surjective
      (presentationModPTruncatedAugmentation (p := p) (G := G) N)
ClassFieldTower.ProP.presentationModP_truncatedFoxSequence_rightExact

Concrete right-exact data for the truncated mod-p Fox sequence.

Source context 10 commands

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

namespace ClassFieldTower.ProP
open CompletedGroupAlgebra
open FoxDifferential
open ProCGroups
noncomputable section
universe u
variable {p d r : ℕ} [Fact p.Prime]
variable {sourceData :
  FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
    (FiniteGroupClass.pGroup p)}
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
theorem presentationModP_truncatedFoxSequence_rightExact
    (P : FiniteProPPresentation p d r sourceData G)
    (ν : Fin r → ℕ)
    (hν : ∀ j, P.RelatorZassenhausDepthAtLeast (ν j) j)
    (N : ℕ) :
    Function.Exact (presentationModPTruncatedRelationMap P ν hν N)
        (presentationModPTruncatedFoxBoundary P N) ∧
      Function.Exact (presentationModPTruncatedFoxBoundary P N)
        (presentationModPTruncatedAugmentation (p := p) (G := G) N) ∧
      Function.Surjective
        (presentationModPTruncatedAugmentation (p := p) (G := G) N)