Centre( G )
Centre returns the centre of G.
The centre of a group G is defined as the centralizer of G in G.
Note that Centre sets and tests the record component G.centre.
gap> d8 := Group( (1,2,3,4), (1,2)(3,4) );
Group( (1,2,3,4), (1,2)(3,4) )
gap> Centre( d8 );
Subgroup( Group( (1,2,3,4), (1,2)(3,4) ), [ (1,3)(2,4) ] )
The default group function GroupOps.Centre uses Centralizer (see
Centralizer) in order to compute the centralizer of G in G.
GAP 3.4.4