Module

Basic.lean

Nyll.ProCGroups.ProP.Presentation.Basic
6 declarations indexed from sourceView source ↗

Finite pro-p presentations

This leaf packages an actual finite free pro-p source, a displayed finite relator family, and the existing IsFreePresentationOf certificate. The free source data is a type index, rather than a structure field, so its canonical group and topology instances remain syntactically determined.

Declarations

ClassFieldTower.ProP.FiniteProPPresentation

A finite pro-p presentation with d generators and r displayed relators.

Source context 6 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
structure FiniteProPPresentation
    (p d r : ℕ) [Fact p.Prime]
    (sourceData :
      FreeProC.EpimorphicallyFreeProCGroupOnConvergingSetData.{u, u}
        (FiniteGroupClass.pGroup p))
    (G : Type u) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G] where
  /-- The chosen free basis has cardinality `d`. -/
  basisCard : Cardinal.mk sourceData.basis = d
  /-- The displayed family of `r` relators in the free source. -/
  relator : Fin r → sourceData.carrier
  /-- The quotient is the closed normal quotient by the displayed relators. -/
  isPresentation :
    IsFreePresentationOf
      (X := ULift.{u} (Fin d))
      (F := sourceData.carrier)
      (G := G)
      (FiniteGroupClass.pGroup p)
      (CrowellExactSequence.freeProCChosenULiftFamilyOfBasisCard
        sourceData basisCard)
      (Set.range relator)
ClassFieldTower.ProP.FiniteProPPresentation.quotient

The canonical quotient map selected by the underlying presentation.

Source context 11 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
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]
def quotient (P : FiniteProPPresentation p d r sourceData G) :
    sourceData.carrier →ₜ* G
ClassFieldTower.ProP.FiniteProPPresentation.quotient_surjective

The presentation quotient is surjective.

Source context 11 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
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 quotient_surjective (P : FiniteProPPresentation p d r sourceData G) :
    Function.Surjective P.quotient
ClassFieldTower.ProP.FiniteProPPresentation.kernel_eq_closedNormalClosure

The kernel is the closed normal closure of the displayed relators.

Source context 11 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
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 kernel_eq_closedNormalClosure
    (P : FiniteProPPresentation p d r sourceData G) :
    P.quotient.toMonoidHom.ker = closedNormalClosure (Set.range P.relator)
ClassFieldTower.ProP.FiniteProPPresentation.targetProP

The target has a pro-p open-normal basis.

Source context 11 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
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 targetProP (P : FiniteProPPresentation p d r sourceData G) :
    ProC.HasPGroupOpenNormalBasis p G
ClassFieldTower.ProP.FiniteProPPresentation.relator_mem_kernel

Every displayed relator lies in the presentation kernel.

Source context 11 commands

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

open scoped Topology
namespace ClassFieldTower.ProP
open ProCGroups
open ProCGroups.Presentations
noncomputable section
universe u
namespace FiniteProPPresentation
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 relator_mem_kernel
    (P : FiniteProPPresentation p d r sourceData G) (i : Fin r) :
    P.relator i ∈ P.quotient.toMonoidHom.ker