Module

Carrier.lean

Nyll.ProCGroups.CompletedGroupAlgebra.Basic.AllFinite.Carrier
13 declarations indexed from sourceView source ↗

Completed Group Algebra / Basic / All Finite / Carrier

This module defines the all-finite completed group algebra as a named inverse-limit carrier. Its compatible-family realization is available only through the explicit equivalence, coordinate projection, compatibility, and extensionality API below. Ring and module structures are inherited once from the generic inverse-limit construction.

Declarations

CompletedGroupAlgebra.CompletedGroupAlgebraCarrier

The all-finite completed group algebra \(\widehat{R[G]}=\varprojlim_U R[G/U]\), kept opaque from 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
def CompletedGroupAlgebraCarrier (R : Type u) (G : Type v) [CommRing R]
    [TopologicalSpace R] [IsTopologicalRing R] [Group G] [TopologicalSpace G]
    [IsTopologicalGroup G] : Type (max u v)
CompletedGroupAlgebra.instTopologicalSpaceCompletedGroupAlgebraCarrier

The completed group algebra carries the inverse-limit topology of its finite stages.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
instance instTopologicalSpaceCompletedGroupAlgebraCarrier :
    TopologicalSpace (CompletedGroupAlgebraCarrier R G)
CompletedGroupAlgebra.completedGroupAlgebraCompatibleFamilyEquiv

Explicit exchange between the named completed carrier and the concrete compatible-family realization. Ordinary code should use finite-stage projections instead.

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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
def completedGroupAlgebraCompatibleFamilyEquiv
    (R : Type u) (G : Type v) [CommRing R] [TopologicalSpace R]
    [IsTopologicalRing R] [Group G] [TopologicalSpace G] [IsTopologicalGroup G] :
    CompletedGroupAlgebraCarrier R G ≃
      (completedGroupAlgebraSystem R G).inverseLimit
CompletedGroupAlgebra.instRingCompletedGroupAlgebraSystemStage
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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U)
CompletedGroupAlgebra.instModuleCompletedGroupAlgebraSystemStage
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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U)
CompletedGroupAlgebra.instIsRingSystemCompletedGroupAlgebraSystem

The all-finite tower is a ring-valued inverse system.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
instance instIsRingSystemCompletedGroupAlgebraSystem :
    IsRingSystem (completedGroupAlgebraSystem R G) where
  map_zero := by
    intro U V hUV
    exact map_zero (completedGroupAlgebraTransition R G hUV)
  map_one := by
    intro U V hUV
    exact map_one (completedGroupAlgebraTransition R G hUV)
  map_add := by
    intro U V hUV x y
    exact map_add (completedGroupAlgebraTransition R G hUV) x y
  map_mul := by
    intro U V hUV x y
    exact map_mul (completedGroupAlgebraTransition R G hUV) x y
CompletedGroupAlgebra.instRingCompletedGroupAlgebra

The ring structure is inherited once from the generic ring inverse limit.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
instance instRingCompletedGroupAlgebra :
    Ring (CompletedGroupAlgebraCarrier R G)
CompletedGroupAlgebra.completedGroupAlgebraProjection

The canonical finite-stage projection, bundled at its source as a ring homomorphism.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
def completedGroupAlgebraProjection
    (R : Type u) (G : Type v) [CommRing R] [TopologicalSpace R]
    [IsTopologicalRing R] [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
    (U : CompletedGroupAlgebraIndex G) :
    CompletedGroupAlgebraCarrier R G →+* CompletedGroupAlgebraStage R G U
CompletedGroupAlgebra.completedGroupAlgebraProjection_compatible

The canonical projections satisfy the inverse-system compatibility equations.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
theorem completedGroupAlgebraProjection_compatible
    (x : CompletedGroupAlgebraCarrier R G)
    {U V : CompletedGroupAlgebraIndex G} (hUV : U ≤ V) :
    completedGroupAlgebraTransition R G hUV
        (completedGroupAlgebraProjection R G V x) =
      completedGroupAlgebraProjection R G U x
CompletedGroupAlgebra.completedGroupAlgebra_ext

Completed elements are equal when all bundled finite-stage projections agree.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
theorem completedGroupAlgebra_ext {x y : CompletedGroupAlgebraCarrier R G}
    (h : ∀ U, completedGroupAlgebraProjection R G U x =
      completedGroupAlgebraProjection R G U y) :
    x = y
CompletedGroupAlgebra.completedGroupAlgebraTransition_smul

Transition maps commute with coefficient scalar multiplication.

Source context 13 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
omit [TopologicalSpace R] [IsTopologicalRing R] in
theorem completedGroupAlgebraTransition_smul
    {U V : CompletedGroupAlgebraIndex G} (hUV : U ≤ V)
    (r : R) (x : CompletedGroupAlgebraStage R G V) :
    completedGroupAlgebraTransition R G hUV (r • x) =
      r • completedGroupAlgebraTransition R G hUV x
CompletedGroupAlgebra.instIsModuleSystemCompletedGroupAlgebra

The all-finite tower is a module-valued inverse system over its coefficient ring.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
instance instIsModuleSystemCompletedGroupAlgebra :
    @IsModuleSystem _ _ R _ (completedGroupAlgebraSystem R G)
      (fun U => @Ring.toAddCommGroup _
        (instRingCompletedGroupAlgebraSystemStage (G := G) (R := R) U))
      (fun U => instModuleCompletedGroupAlgebraSystemStage (G := G) (R := R) U) :=
  @IsModuleSystem.mk _ _ R _ (completedGroupAlgebraSystem R G)
    (fun U => @Ring.toAddCommGroup _
      (instRingCompletedGroupAlgebraSystemStage (G := G) (R := R) U))
    (fun U => instModuleCompletedGroupAlgebraSystemStage (G := G) (R := R) U)
    (completedGroupAlgebraTransition_smul (R := R) (G := G))
CompletedGroupAlgebra.instModuleCoeffCompletedGroupAlgebra

The module structure is inherited once from the generic module inverse limit.

Source context 12 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 (G : Type v) [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
variable (R : Type u) [CommRing R] [TopologicalSpace R] [IsTopologicalRing R]
local instance instRingCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Ring ((completedGroupAlgebraSystem R G).X U) := by
  change Ring (CompletedGroupAlgebraStage R G U)
  infer_instance
local instance instModuleCompletedGroupAlgebraSystemStage
    (U : CompletedGroupAlgebraIndex G) :
    Module R ((completedGroupAlgebraSystem R G).X U) := by
  change Module R (CompletedGroupAlgebraStage R G U)
  infer_instance
instance instModuleCoeffCompletedGroupAlgebra :
    Module R (CompletedGroupAlgebraCarrier R G)