ProCGroups.FoxDifferential.Completed.Comparison.SourceProjection
The principal declarations in this module are:
freeProCZCCompletedFoxBoundary_finiteStageProjectionFinite-stage projection of the source-shaped completed Fox boundary map. -freeProCZCCompletedFoxBoundary_finiteStageProjection_stageFinite-stage projection of the source-shaped completed Fox boundary map, with generator boundaries written in the selected finite pro-Cquotient. -zcFreeFoxCoordinatesMap_finiteStageProjectionComponentwise finite-stage projection formula for target maps on completed Fox coordinates. -freeProCZCCompletedFoxBoundary_mapTarget_finiteStageProjection_stageFinite-stage projection of target naturality for source-shaped completed Fox boundary maps.
imports
theorem freeProCZCCompletedFoxBoundary_finiteStageProjection
(φ : X → H) (v : ZCFreeFoxCoordinates C (X := X) (H := H))
(j : ZCCompletedGroupAlgebraIndex C H) :
zcCompletedGroupAlgebraProjection C H j
(freeProCZCCompletedFoxBoundary C φ v) =
∑ x : X,
zcCompletedGroupAlgebraProjection C H j (v x) *
zcCompletedGroupAlgebraProjection C H j (zcGroupLike C H (φ x) - 1)Finite-stage projection of the source-shaped completed Fox boundary map.
Show Lean proof
by
rw [freeProCZCCompletedFoxBoundary_apply, zcCompletedGroupAlgebraProjection_sum]
apply Finset.sum_congr rfl
intro x _
simp only [zcCompletedGroupAlgebraProjection, zcCompletedGroupAlgebraProjection_mul,
zcCompletedGroupAlgebraProjection_sub, zcCompletedGroupAlgebraProjection_groupLike,
MonoidAlgebra.of_apply,
zcCompletedGroupAlgebraProjection_one]
theorem freeProCZCCompletedFoxBoundary_finiteStageProjection_stage
(φ : X → H) (v : ZCFreeFoxCoordinates C (X := X) (H := H))
(j : ZCCompletedGroupAlgebraIndex C H) :
zcCompletedGroupAlgebraProjection C H j
(freeProCZCCompletedFoxBoundary C φ v) =
∑ x : X,
zcCompletedGroupAlgebraProjection C H j (v x) *
(MonoidAlgebra.of (ModNCompletedCoeff j.1.modulus)
(CompletedGroupAlgebraQuotientInClass H C j.2)
(QuotientGroup.mk (φ x)) - 1)Finite-stage projection of the source-shaped completed Fox boundary map, with generator boundaries written in the selected finite pro-C quotient.
Show Lean proof
by
simpa [zcCompletedGroupAlgebraProjection] using
freeProCZCCompletedFoxBoundary_finiteStageProjection
(C := C) (X := X) (H := H) φ v j
omit [Fintype X] in
theorem zcFreeFoxCoordinatesMap_finiteStageProjection
(η : H →ₜ* K)
(v : ZCFreeFoxCoordinates C (X := X) (H := H))
(j : ZCCompletedGroupAlgebraIndex C K) (x : X) :
zcCompletedGroupAlgebraProjection C K j
(zcFreeFoxCoordinatesMap (X := X) C hC η v x) =
zcCompletedGroupAlgebraMapStage C hC η j
(zcCompletedGroupAlgebraProjection C H
(j.1, completedGroupAlgebraComapIndexInClass
(G := H) (H := K) C hC η j.2) (v x))Componentwise finite-stage projection formula for target maps on completed Fox coordinates.
Show Lean proof
by
simp only [zcFreeFoxCoordinatesMap, zcCompletedGroupAlgebraProjection_map]
theorem freeProCZCCompletedFoxBoundary_mapTarget_finiteStageProjection_stage
(η : H →ₜ* K) (φ : X → H)
(v : ZCFreeFoxCoordinates C (X := X) (H := H))
(j : ZCCompletedGroupAlgebraIndex C K) :
zcCompletedGroupAlgebraProjection C K j
(zcCompletedGroupAlgebraMap C hC η (freeProCZCCompletedFoxBoundary C φ v)) =
∑ x : X,
zcCompletedGroupAlgebraMapStage C hC η j
(zcCompletedGroupAlgebraProjection C H
(j.1, completedGroupAlgebraComapIndexInClass
(G := H) (H := K) C hC η j.2) (v x)) *
(MonoidAlgebra.of (ModNCompletedCoeff j.1.modulus)
(CompletedGroupAlgebraQuotientInClass K C j.2)
(QuotientGroup.mk (η (φ x))) - 1)Finite-stage projection of target naturality for source-shaped completed Fox boundary maps.
Show Lean proof
by
rw [freeProCZCCompletedFoxBoundary_mapTarget]
rw [freeProCZCCompletedFoxBoundary_finiteStageProjection_stage]
apply Finset.sum_congr rfl
intro x _
rw [zcFreeFoxCoordinatesMap_finiteStageProjection]
omit [DecidableEq X] in
theorem ZCFiniteStageQuotientBundle.finite_completedGroupAlgebraStage
(C : ProCGroups.FiniteGroupClass.{u})
(B : ZCFiniteStageQuotientBundle N)
(j : B.Index C) :
letI : TopologicalSpace B.Target := B.targetTopology
letI : IsTopologicalGroup B.Target := B.targetIsTopologicalGroup
Finite (ZCCompletedGroupAlgebraStage C B.Target j)A quotient bundle certifies that every associated pro-C completed group-algebra stage is actually finite. This is the canonical finite-stage consumer of ZCFiniteStageQuotientBundle; the unbundled comparison lemmas remain purely algebraic.
Show Lean proof
by
letI : TopologicalSpace B.Target := B.targetTopology
letI : IsTopologicalGroup B.Target := B.targetIsTopologicalGroup
letI : Fact (0 < j.1.modulus) := ⟨j.1.positive⟩
exact
finite_modNCompletedGroupAlgebraStageInClass
(n := j.1.modulus) (G := B.Target) C j.2