Module

CofinalQuotientKernelBasis.lean

Nyll.ProCGroups.FoxDifferential.Completed.FreeProC.CofinalQuotientKernelBasis
6 declarations indexed from sourceView source ↗

Fox differential: completed — free pro-\(C\) — cofinal quotient kernel basis

The principal declarations in this module are:

  • HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_ker_le

Reindex an identity-neighborhood quotient-kernel basis along a cofinal refinement of kernels. The hypothesis says that every kernel in the original quotient family contains the kernel of some refined quotient. This is the topological input used to pass from all finite quotients to prime-power or otherwise cofinal stages.

  • HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_ker_le

Reindex a left-neighborhood quotient-kernel basis along a cofinal refinement of kernels. Every kernel in the original family is required to contain a kernel from the refined family.

  • HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_factor

A factorization of the refined quotient through an original quotient gives the required kernel inclusion for identity-neighborhood reindexing.

  • HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_factor

A factorization of each refined quotient through an original quotient gives the kernel inclusion needed to reindex a left-neighborhood quotient-kernel basis.

Declarations

FoxDifferential.HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_ker_le

Reindex an identity-neighborhood quotient-kernel basis along a cofinal refinement of kernels. The hypothesis says that every kernel in the original quotient family contains the kernel of some refined quotient. This is the topological input used to pass from all finite quotients to prime-power or otherwise cofinal stages.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_ker_le
    (hbasis : HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hcofinal : ∀ j : J, ∃ k : K, (π' k).ker ≤ (π j).ker) :
    HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π'
FoxDifferential.HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_ker_le

Reindex a left-neighborhood quotient-kernel basis along a cofinal refinement of kernels. Every kernel in the original family is required to contain a kernel from the refined family.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_ker_le
    (hbasis : HasLeftQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hcofinal : ∀ j : J, ∃ k : K, (π' k).ker ≤ (π j).ker) :
    HasLeftQuotientKernelNeighbourhoodBasis (Y := Y) π'
FoxDifferential.HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_factor

A factorization of the refined quotient through an original quotient gives the required kernel inclusion for identity-neighborhood reindexing.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem HasIdentityQuotientKernelNeighbourhoodBasis.reindex_of_factor
    (hbasis : HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hrefine : ∀ j : J, ∃ k : K, ∃ τ : Q' k →* Q j, τ.comp (π' k) = π j) :
    HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π'
FoxDifferential.HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_factor

A factorization of each refined quotient through an original quotient gives the kernel inclusion needed to reindex a left-neighborhood quotient-kernel basis.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem HasLeftQuotientKernelNeighbourhoodBasis.reindex_of_factor
    (hbasis : HasLeftQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hrefine : ∀ j : J, ∃ k : K, ∃ τ : Q' k →* Q j, τ.comp (π' k) = π j) :
    HasLeftQuotientKernelNeighbourhoodBasis (Y := Y) π'
FoxDifferential.subset_closure_of_identityQuotientKernel_approximation_reindex

Closure approximation can be checked on any cofinal refinement of quotient kernels.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem subset_closure_of_identityQuotientKernel_approximation_reindex
    [IsTopologicalGroup Y]
    {S T : Set Y}
    (hbasis : HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hcofinal : ∀ j : J, ∃ k : K, (π' k).ker ≤ (π j).ker)
    (happrox :
      ∀ y : Y, y ∈ T → ∀ k : K,
        ∃ s : Y, s ∈ S ∧ π' k s = π' k y) :
    T ⊆ closure S
FoxDifferential.subset_closure_of_identityQuotientKernel_stage_exact_reindex

The finite-stage closure approximation can be checked on a cofinal refined quotient family.

Source context 11 commands

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

namespace FoxDifferential
noncomputable section
open scoped Topology
universe u v w
section CofinalReindexing
variable {Y : Type u} [Group Y] [TopologicalSpace Y]
variable {J : Type v} {K : Type w}
variable {Q : J → Type*} [∀ j, Group (Q j)]
variable {Q' : K → Type*} [∀ k, Group (Q' k)]
variable (π : ∀ j : J, Y →* Q j)
variable (π' : ∀ k : K, Y →* Q' k)
theorem subset_closure_of_identityQuotientKernel_stage_exact_reindex
    [IsTopologicalGroup Y]
    {S T : Set Y}
    (hbasis : HasIdentityQuotientKernelNeighbourhoodBasis (Y := Y) π)
    (hcofinal : ∀ j : J, ∃ k : K, (π' k).ker ≤ (π j).ker)
    (Sstage Tstage : ∀ k : K, Set (Q' k))
    (hTstage : ∀ y : Y, y ∈ T → ∀ k : K, π' k y ∈ Tstage k)
    (hstage_exact : ∀ k : K, Tstage k ⊆ Sstage k)
    (hlift_stage : ∀ k : K, ∀ q : Q' k, q ∈ Sstage k →
      ∃ s : Y, s ∈ S ∧ π' k s = q) :
    T ⊆ closure S