Module

Abelian.lean

Nyll.ProCGroups.ProC.GroupPredicates.Abelian
1 declaration indexed from sourceView source ↗

Abelian open-normal quotient bases

This file proves that a profinite group with an abelian open-normal quotient basis is itself abelian. The proof tests commutators in all open normal quotients and then uses profinite separation.

Declarations

ProCGroups.ProC.HasAbelianOpenNormalBasis.isAbelian

A profinite group with an abelian open-normal quotient basis is abelian.

Source context 9 commands

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

open Set
open scoped Topology Pointwise
namespace ProCGroups.ProC
universe u v
open InverseSystems
section
variable {G : Type u} [Group G] [TopologicalSpace G] [IsTopologicalGroup G]
  [CompactSpace G] [T2Space G] [TotallyDisconnectedSpace G]
namespace HasAbelianOpenNormalBasis
omit [T2Space G] in
theorem isAbelian (hG : HasAbelianOpenNormalBasis G) : ∀ a b : G, a * b = b * a