PrefrattiniSubgroup( G )
PrefrattiniSubgroup
returns a Prefrattini subgroup of the group G.
A factor M/N of G is called a Frattini factor if M/N leq phi(G/N) holds. The group P is a Prefrattini subgroup of G if P covers each Frattini chief factor of G, and if for each maximal subgroup of G there exists a conjugate maximal subgroup, which contains P.
gap> s4 := SymmetricGroup( AgWords, 4 );; gap> ss4 := SpecialAgGroup( s4 );; gap> PrefrattiniSubgroup( ss4 ); Subgroup( Group( g1, g2, g3, g4 ), [ ] )
Currently PrefrattiniSubgroup
can only be applied to special Ag groups
(see Special Ag Groups).
GAP 3.4.4