ProCGroups.FoxDifferential.Completed.Continuous.SemidirectKernelBasis
The principal declarations in this module are:
finiteCoordinateZeroRectangularNeighbourhoods_piFinite-coordinate product neighborhoods in a function space contain coordinate rectangles. This is the generic topological input needed to pass from coefficient-kernel bases for \(\mathbb{Z}_C\llbracket H\rrbracket\) to coordinate-kernel bases for \(\mathbb{Z}_C\llbracket H\rrbracket^{X}\). It uses the product topology directly and keeps no algebraic assumptions. -zcFreeFoxCoordinates_hasFiniteCoordinateZeroRectangularNeighbourhoodsStandard product-topology coordinate rectangles for completed Fox-coordinate families. -zcCompletedFoxSemidirect_hasRectangularIdentityNeighbourhoodsIn the standard topology on \(\mathbb{Z}_C\llbracket H\rrbracket^{X} \rtimes H\), every identity neighborhood contains a product rectangle around (0,1) in the coordinate and target components. -freeProCZCFoxSemiZCBifilteredStageMap_identity_basis_of_component_bases_standardTopologyStandard-topology form of the componentwise kernel-basis theorem for actual \(\mathbb{Z}_C\llbracket H\rrbracket\) bifiltered finite stages.
theorem finiteCoordinateZeroRectangularNeighbourhoods_pi :
HasFiniteCoordinateZeroRectangularNeighbourhoods (A := A) (X := X)Finite-coordinate product neighborhoods in a function space contain coordinate rectangles. This is the generic topological input needed to pass from coefficient-kernel bases for \(\mathbb{Z}_C\llbracket H\rrbracket\) to coordinate-kernel bases for \(\mathbb{Z}_C\llbracket H\rrbracket^{X}\). It uses the product topology directly and keeps no algebraic assumptions.
Show Lean proof
by
intro U hU hUzero
classical
rcases (isOpen_pi_iff.mp hU) (0 : X → A) hUzero with ⟨J, W, hW, hJU⟩
let V : X → Set A := fun x => if hx : x ∈ J then W x else Set.univ
refine ⟨V, ?_, ?_⟩
· intro x
by_cases hx : x ∈ J
· simpa [V, hx] using hW x hx
· simp only [dite_eq_ite, hx, ↓reduceIte, isOpen_univ, Set.mem_univ, and_self, V]
· intro v hv
apply hJU
intro x hx
have hvx := hv x
have hxJ : x ∈ J := by
simpa using hx
have hVx : V x = W x := by
simp only [dite_eq_ite, hxJ, ↓reduceIte, V]
rwa [hVx] at hvx
theorem zcFreeFoxCoordinates_hasFiniteCoordinateZeroRectangularNeighbourhoods
(C : ProCGroups.FiniteGroupClass.{u}) (X H : Type u)
[Group H] [TopologicalSpace H] [IsTopologicalGroup H] :
HasFiniteCoordinateZeroRectangularNeighbourhoods
(A := ZCCompletedGroupAlgebra C H) (X := X)Standard product-topology coordinate rectangles for completed Fox-coordinate families.
Show Lean proof
finiteCoordinateZeroRectangularNeighbourhoods_pi
omit [DecidableEq X] in
theorem zcCompletedFoxSemidirect_hasRectangularIdentityNeighbourhoods :
HasSemidirectRectangularIdentityNeighbourhoods
(X := X) (H := H) CIn the standard topology on \(\mathbb{Z}_C\llbracket H\rrbracket^{X} \rtimes H\), every identity neighborhood contains a product rectangle around (0,1) in the coordinate and target components.
Show Lean proof
by
intro U hU hUone
rcases isOpen_induced_iff.mp hU with ⟨V, hVopen, hVeq⟩
have hVone :
((0 : ZCFreeFoxCoordinates C (X := X) (H := H)), (1 : H)) ∈ V := by
have hpre :
(1 : ZCCompletedFoxSemidirect C X H) ∈
(fun a : ZCCompletedFoxSemidirect C X H => (a.left, a.right)) ⁻¹' V := by
simpa [hVeq]
using hUone
simpa using hpre
have hVnhds : V ∈ 𝓝 ((0 : ZCFreeFoxCoordinates C (X := X) (H := H)), (1 : H)) :=
hVopen.mem_nhds hVone
rcases mem_nhds_prod_iff.mp hVnhds with ⟨UL₀, hUL₀, UR₀, hUR₀, hprod⟩
rcases mem_nhds_iff.mp hUL₀ with ⟨UL, hULsub, hULopen, hULzero⟩
rcases mem_nhds_iff.mp hUR₀ with ⟨UR, hURsub, hURopen, hURone⟩
refine ⟨UL, UR, hULopen, hULzero, hURopen, hURone, ?_⟩
intro y hyL hyR
have hyV : (y.left, y.right) ∈ V :=
hprod (show (y.left, y.right) ∈ UL₀ ×ˢ UR₀ from ⟨hULsub hyL, hURsub hyR⟩)
have hyUpre : y ∈
(fun a : ZCCompletedFoxSemidirect C X H => (a.left, a.right)) ⁻¹' V := hyV
simpa [hVeq] using hyUpre
omit [DecidableEq X] [∀ (j : J), Fact (0 < nstage j)] in
theorem freeProCZCFoxSemiZCBifilteredStageMap_identity_basis_of_component_bases_standardTopology
(hdir : Directed (· ≤ ·) (id : J → J))
(hcoeff_mod : ∀ {i j : J} (hij : i ≤ j),
∀ a : ModNCompletedCoeff (zcIndex j).1.modulus,
modNCompletedCoeffMap
(n := nstage i) (m := (zcIndex i).1.modulus) (hmod i)
(modNCompletedCoeffMap
(n := (zcIndex i).1.modulus) (m := (zcIndex j).1.modulus)
(hzcIndex hij).1 a) =
modNCompletedCoeffMap (n := nstage i) (m := nstage j) (hn hij)
(modNCompletedCoeffMap
(n := nstage j) (m := (zcIndex j).1.modulus) (hmod j) a))
(hqmap_transition : ∀ {i j : J} (hij : i ≤ j),
∀ q : CompletedGroupAlgebraQuotientInClass H C (zcIndex j).2,
qmap i
((OpenNormalSubgroupInClass.map
(C := C) (G := H)
(U := OrderDual.ofDual (zcIndex i).2)
(V := OrderDual.ofDual (zcIndex j).2)
(hzcIndex hij).2) q) =
foxAlgebraicStageTargetQuotientMap (X := X) (hN hij) (qmap j q))
(hleft_basis :
HasAdditiveIdentityQuotientKernelNeighbourhoodBasis
(A := ZCFreeFoxCoordinates C (X := X) (H := H))
(fun j : J =>
zcFreeFoxCoordinatesBifilteredStageMap
(C := C) (X := X) (H := H) Nstage nstage
(fun k => zcCompletedGroupAlgebraBifilteredStageCoeffMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap k) j))
(hright_basis :
HasIdentityQuotientKernelNeighbourhoodBasis
(Y := H)
(fun j : J =>
zcCompletedGroupAlgebraBifilteredStageRightMap
(C := C) (X := X) (H := H) Nstage zcIndex qmap j)) :
HasIdentityQuotientKernelNeighbourhoodBasis
(Y := ZCCompletedFoxSemidirect C X H)
(fun j : J =>
freeProCZCCompletedFoxSemidirectZCBifilteredStageMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap j)Standard-topology form of the componentwise kernel-basis theorem for actual \(\mathbb{Z}_C\llbracket H\rrbracket\) bifiltered finite stages.
Show Lean proof
by
exact
freeProCZCFoxSemiZCBifilteredStageMap_identity_basis_of_component_bases
(C := C) (X := X) (H := H) Nstage nstage hN hn zcIndex hzcIndex
hmod qmap
(zcCompletedFoxSemidirect_hasRectangularIdentityNeighbourhoods
(C := C) X H)
hdir hcoeff_mod hqmap_transition hleft_basis hright_basis
omit [DecidableEq X] [∀ (j : J), Fact (0 < nstage j)] in
theorem zcFreeFoxCoordinatesBifilteredStageMap_additive_basis_of_coeff_basis_standardTopology
[Finite X] [Nonempty J]
(hdir : Directed (· ≤ ·) (id : J → J))
(hcoeff_mod : ∀ {i j : J} (hij : i ≤ j),
∀ a : ModNCompletedCoeff (zcIndex j).1.modulus,
modNCompletedCoeffMap
(n := nstage i) (m := (zcIndex i).1.modulus) (hmod i)
(modNCompletedCoeffMap
(n := (zcIndex i).1.modulus) (m := (zcIndex j).1.modulus)
(hzcIndex hij).1 a) =
modNCompletedCoeffMap (n := nstage i) (m := nstage j) (hn hij)
(modNCompletedCoeffMap
(n := nstage j) (m := (zcIndex j).1.modulus) (hmod j) a))
(hqmap_transition : ∀ {i j : J} (hij : i ≤ j),
∀ q : CompletedGroupAlgebraQuotientInClass H C (zcIndex j).2,
qmap i
((OpenNormalSubgroupInClass.map
(C := C) (G := H)
(U := OrderDual.ofDual (zcIndex i).2)
(V := OrderDual.ofDual (zcIndex j).2)
(hzcIndex hij).2) q) =
foxAlgebraicStageTargetQuotientMap (X := X) (hN hij) (qmap j q))
(hcoeff_basis :
HasAdditiveIdentityQuotientKernelNeighbourhoodBasis
(A := ZCCompletedGroupAlgebra C H)
(fun j : J =>
(zcCompletedGroupAlgebraBifilteredStageCoeffMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap j).toAddMonoidHom)) :
HasAdditiveIdentityQuotientKernelNeighbourhoodBasis
(A := ZCFreeFoxCoordinates C (X := X) (H := H))
(fun j : J =>
zcFreeFoxCoordinatesBifilteredStageMap
(C := C) (X := X) (H := H) Nstage nstage
(fun k => zcCompletedGroupAlgebraBifilteredStageCoeffMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap k) j)Standard-topology additive kernel basis for completed Fox coordinates, reduced to the coefficient-ring kernel basis. For finite Fox coordinate families, product neighborhoods give the coordinate rectangles needed for the coordinate-kernel theorem.
Show Lean proof
by
exact
zcFreeFoxCoordinatesBifilteredStageMap_additive_basis_of_coeff_basis
(C := C) (X := X) (H := H) Nstage nstage hN hn zcIndex hzcIndex
hmod qmap
(zcFreeFoxCoordinates_hasFiniteCoordinateZeroRectangularNeighbourhoods
(C := C) X H)
hdir hcoeff_mod hqmap_transition hcoeff_basis
omit [DecidableEq X] [∀ (j : J), Fact (0 < nstage j)] in
theorem semiZCBiStageMap_identityBasis_of_coeff_rightBases
[Finite X] [Nonempty J]
(hdir : Directed (· ≤ ·) (id : J → J))
(hcoeff_mod : ∀ {i j : J} (hij : i ≤ j),
∀ a : ModNCompletedCoeff (zcIndex j).1.modulus,
modNCompletedCoeffMap
(n := nstage i) (m := (zcIndex i).1.modulus) (hmod i)
(modNCompletedCoeffMap
(n := (zcIndex i).1.modulus) (m := (zcIndex j).1.modulus)
(hzcIndex hij).1 a) =
modNCompletedCoeffMap (n := nstage i) (m := nstage j) (hn hij)
(modNCompletedCoeffMap
(n := nstage j) (m := (zcIndex j).1.modulus) (hmod j) a))
(hqmap_transition : ∀ {i j : J} (hij : i ≤ j),
∀ q : CompletedGroupAlgebraQuotientInClass H C (zcIndex j).2,
qmap i
((OpenNormalSubgroupInClass.map
(C := C) (G := H)
(U := OrderDual.ofDual (zcIndex i).2)
(V := OrderDual.ofDual (zcIndex j).2)
(hzcIndex hij).2) q) =
foxAlgebraicStageTargetQuotientMap (X := X) (hN hij) (qmap j q))
(hcoeff_basis :
HasAdditiveIdentityQuotientKernelNeighbourhoodBasis
(A := ZCCompletedGroupAlgebra C H)
(fun j : J =>
(zcCompletedGroupAlgebraBifilteredStageCoeffMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap j).toAddMonoidHom))
(hright_basis :
HasIdentityQuotientKernelNeighbourhoodBasis
(Y := H)
(fun j : J =>
zcCompletedGroupAlgebraBifilteredStageRightMap
(C := C) (X := X) (H := H) Nstage zcIndex qmap j)) :
HasIdentityQuotientKernelNeighbourhoodBasis
(Y := ZCCompletedFoxSemidirect C X H)
(fun j : J =>
freeProCZCCompletedFoxSemidirectZCBifilteredStageMap
(C := C) (X := X) (H := H) Nstage nstage zcIndex hmod qmap j)The semidirect kernel basis for the standard topology from coefficient and target component bases. This is the componentwise kernel-basis theorem with the left coordinate basis built internally from the coefficient maps \(\mathbb{Z}_C\llbracket H\rrbracket \to (\mathbb{Z}/n_j\mathbb{Z})[F/N_j]\).
Show Lean proof
by
exact
freeProCZCFoxSemiZCBifilteredStageMap_identity_basis_of_component_bases_standardTopology
(C := C) (X := X) (H := H) Nstage nstage hN hn zcIndex hzcIndex
hmod qmap hdir hcoeff_mod hqmap_transition
(zcFreeFoxCoordinatesBifilteredStageMap_additive_basis_of_coeff_basis_standardTopology
(C := C) (X := X) (H := H) Nstage nstage hN hn zcIndex hzcIndex
hmod qmap hdir hcoeff_mod hqmap_transition hcoeff_basis)
hright_basis