Module

PGroupFormation.lean

Nyll.ProCGroups.FiniteGroups.PGroupFormation
1 declaration indexed from sourceView source ↗

The full formation of finite p-groups

The existing formation, subgroup closure and extension closure proofs supply the full-formation property used by maximal pro-p residual quotients.

Declarations

ProCGroups.FiniteGroupClass.pGroup_fullFormation

Finite p-groups form a full formation, using their established subgroup and extension closure properties.

Source context 1 command

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

namespace ProCGroups.FiniteGroupClass
theorem pGroup_fullFormation (p : ℕ) [Fact p.Prime] : FullFormation (pGroup p) where
  melnikovFormation :=
    { formation := pGroup_formation p
      normalSubgroupClosed := fun N _ hG => pGroup_subgroupClosed p N hG
      extensionClosed := pGroup_extensionClosed p }
  subgroupClosed := pGroup_subgroupClosed p