FittingSubgroup( G )
FittingSubgroup returns the Fitting subgroup of G.
The Fitting subgroup of a group G is the biggest nilpotent normal subgroup of G.
gap> s4;
Group( (1,2,3,4), (1,2) )
gap> FittingSubgroup( s4 );
Subgroup( Group( (1,2,3,4), (1,2) ), [ (1,3)(2,4), (1,4)(2,3) ] )
gap> IsNilpotent( last );
true
Let G be a finite group. Then the default group function
GroupOps.FittingSubgroup computes the subgroup of G generated by the
cores of the Sylow subgroups in G.
GAP 3.4.4