Module

System.lean

Nyll.ProCGroups.CompletedGroupAlgebra.OpenFiniteQuotientTopology.OpenFiniteLimit.System
10 declarations indexed from sourceView source ↗

Completed Group Algebra / Open Finite Quotient Topology / Open Finite Limit / System

This module defines the two-parameter open-finite quotient system and its named inverse-limit carrier. The compatible-family representation is exposed only by an explicit equivalence and the canonical projection/compatibility/extensionality API.

Declarations

CompletedGroupAlgebra.completedGroupAlgebraOpenFiniteQuotientSystem

The two-parameter inverse system \(K = (I, U) \mapsto (R/I)[G/U]\) for the kernel-neighborhood topology.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraOpenFiniteQuotientSystem
    (R : Type u) (G : Type v) [CommRing R] [TopologicalSpace R] [Group G]
    [TopologicalSpace G] [IsTopologicalGroup G] :
    ProCGroups.InverseSystems.InverseSystem
      (I := CompletedGroupAlgebraOpenQuotientIndex R G) where
  X := CompletedGroupAlgebraOpenQuotientStage R G
  topologicalSpace := completedGroupAlgebraOpenFiniteQuotientStageTopology R G
  map := fun {K L} hKL => completedGroupAlgebraOpenFiniteQuotientTransition R G hKL
  continuous_map := by
    intro K L hKL
    let : TopologicalSpace (CompletedGroupAlgebraOpenQuotientStage R G K) :=
      completedGroupAlgebraOpenFiniteQuotientStageTopology R G K
    let : TopologicalSpace (CompletedGroupAlgebraOpenQuotientStage R G L) :=
      completedGroupAlgebraOpenFiniteQuotientStageTopology R G L
    have : DiscreteTopology (CompletedGroupAlgebraOpenQuotientStage R G L) :=
      completedGroupAlgebraOpenFiniteQuotientStage_discrete R G L
    exact continuous_of_discreteTopology
  map_id := by
    intro K
    exact congrArg DFunLike.coe
      (completedGroupAlgebraOpenFiniteQuotientTransition_id R G K)
  map_comp := by
    intro K L M hKL hLM
    exact congrArg DFunLike.coe
      (completedGroupAlgebraOpenFiniteQuotientTransition_comp R G hKL hLM)
CompletedGroupAlgebra.CompletedGroupAlgebraOpenFiniteQuotientLimit

The two-parameter inverse limit \(\varprojlim_{I,U}(R/I)[G/U]\), kept opaque from its concrete compatible-family realization.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def CompletedGroupAlgebraOpenFiniteQuotientLimit
    (R : Type u) (G : Type v) [CommRing R] [TopologicalSpace R] [Group G]
    [TopologicalSpace G] [IsTopologicalGroup G] :
    Type (max u v)
CompletedGroupAlgebra.instTopologicalSpaceCompletedGroupAlgebraOpenFiniteQuotientLimit

The two-parameter completion carries its inverse-limit topology.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
instance instTopologicalSpaceCompletedGroupAlgebraOpenFiniteQuotientLimit :
    TopologicalSpace (CompletedGroupAlgebraOpenFiniteQuotientLimit R G)
CompletedGroupAlgebra.completedGroupAlgebraOpenFiniteQuotientCompatibleFamilyEquiv

Explicit exchange between the named two-parameter carrier and its compatible-family model.

Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
def completedGroupAlgebraOpenFiniteQuotientCompatibleFamilyEquiv :
    CompletedGroupAlgebraOpenFiniteQuotientLimit R G ≃
      (completedGroupAlgebraOpenFiniteQuotientSystem R G).inverseLimit
Source context 10 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K)
CompletedGroupAlgebra.instIsRingSystemCompletedGroupAlgebraOpenFiniteQuotientSystem

The open-finite quotient tower is a ring-valued inverse system.

Source context 11 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K) := by
  change Ring (CompletedGroupAlgebraOpenQuotientStage R G K)
  infer_instance
instance instIsRingSystemCompletedGroupAlgebraOpenFiniteQuotientSystem :
    IsRingSystem (completedGroupAlgebraOpenFiniteQuotientSystem R G) where
  map_zero := by
    intro K L hKL
    exact map_zero (completedGroupAlgebraOpenFiniteQuotientTransition R G hKL)
  map_one := by
    intro K L hKL
    exact map_one (completedGroupAlgebraOpenFiniteQuotientTransition R G hKL)
  map_add := by
    intro K L hKL x y
    exact map_add (completedGroupAlgebraOpenFiniteQuotientTransition R G hKL) x y
  map_mul := by
    intro K L hKL x y
    exact map_mul (completedGroupAlgebraOpenFiniteQuotientTransition R G hKL) x y
CompletedGroupAlgebra.instRingCompletedGroupAlgebraOpenFiniteQuotientLimit

The two-parameter completion inherits its ring structure from the generic inverse limit.

Source context 11 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K) := by
  change Ring (CompletedGroupAlgebraOpenQuotientStage R G K)
  infer_instance
instance instRingCompletedGroupAlgebraOpenFiniteQuotientLimit :
    Ring (CompletedGroupAlgebraOpenFiniteQuotientLimit R G)
CompletedGroupAlgebra.completedGroupAlgebraOpenFiniteQuotientLimitProjection

The canonical projection to one quotient \((R/I)[G/U]\), bundled at its source as a ring homomorphism.

Source context 11 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K) := by
  change Ring (CompletedGroupAlgebraOpenQuotientStage R G K)
  infer_instance
def completedGroupAlgebraOpenFiniteQuotientLimitProjection
    (R : Type u) (G : Type v) [CommRing R] [TopologicalSpace R] [Group G]
    [TopologicalSpace G] [IsTopologicalGroup G]
    (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    CompletedGroupAlgebraOpenFiniteQuotientLimit R G →+*
      CompletedGroupAlgebraOpenQuotientStage R G K
CompletedGroupAlgebra.completedGroupAlgebraOpenFiniteQuotientLimitProjection_compatible

The open-finite quotient projections satisfy the two-parameter transition equations.

Source context 11 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K) := by
  change Ring (CompletedGroupAlgebraOpenQuotientStage R G K)
  infer_instance
theorem completedGroupAlgebraOpenFiniteQuotientLimitProjection_compatible
    {K L : CompletedGroupAlgebraOpenQuotientIndex R G} (hKL : K ≤ L)
    (x : CompletedGroupAlgebraOpenFiniteQuotientLimit R G) :
    completedGroupAlgebraOpenFiniteQuotientTransition R G hKL
        (completedGroupAlgebraOpenFiniteQuotientLimitProjection R G L x) =
      completedGroupAlgebraOpenFiniteQuotientLimitProjection R G K x
CompletedGroupAlgebra.completedGroupAlgebraOpenFiniteQuotientLimit_ext

Two open-finite quotient completed elements are equal when all bundled coordinates agree.

Source context 11 commands

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

open scoped Topology
namespace CompletedGroupAlgebra
noncomputable section
open ProCGroups
open ProCGroups.ProC
open ProCGroups.InverseSystems
open ProCGroups.Completion
universe u v
variable (R : Type u) [CommRing R] [TopologicalSpace R]
variable (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
local instance (K : CompletedGroupAlgebraOpenQuotientIndex R G) :
    Ring ((completedGroupAlgebraOpenFiniteQuotientSystem R G).X K) := by
  change Ring (CompletedGroupAlgebraOpenQuotientStage R G K)
  infer_instance
theorem completedGroupAlgebraOpenFiniteQuotientLimit_ext
    {x y : CompletedGroupAlgebraOpenFiniteQuotientLimit R G}
    (h : ∀ K, completedGroupAlgebraOpenFiniteQuotientLimitProjection R G K x =
      completedGroupAlgebraOpenFiniteQuotientLimitProjection R G K y) :
    x = y