gap> START_TEST( "idempot.tst");
gap> G:=SymmetricGroup(4);
Sym( [ 1 .. 4 ] )
gap> S:=StrongShodaPairs(G);;
gap> Length(S);
5
gap> List(S,x->List(x,StructureDescription));
[ [ "S4", "S4" ], [ "S4", "A4" ], [ "A4", "C2 x C2" ], [ "D8", "C2 x C2" ],
[ "D8", "C4" ] ]
gap> K:=S[5][1];;
gap> H:=S[5][2];;
gap> QG:=GroupRing(Rationals,G);
<algebra-with-one over Rationals, with 2 generators>
gap> CentralElementBySubgroups(QG,K,H);
(3/8)*()+(-1/8)*(3,4)+(-1/8)*(2,3)+(-1/8)*(2,4)+(-1/8)*(1,2)+(-1/8)*(1,2)
(3,4)+(1/8)*(1,2,3,4)+(1/8)*(1,2,4,3)+(1/8)*(1,3,4,2)+(-1/8)*(1,3)+(-1/8)*
(1,3)(2,4)+(1/8)*(1,3,2,4)+(1/8)*(1,4,3,2)+(-1/8)*(1,4)+(1/8)*(1,4,2,3)+(-1/
8)*(1,4)(2,3)
gap> STOP_TEST( "idempot.tst", 1 );
[ Dauer der Verarbeitung: 0.14 Sekunden
(vorverarbeitet)
]