Dear Mr. Sorouhesh You can use the following command gap> RequirePackage("SONATA");; gap> Subgroups(SmallGroup(4,2)); [ Group([ ]), Group([ f1 ]), Group([ f2 ]), Group([ f1*f2 ]), Group([ f1, f2 ]) ] gap> Regards; Fatemeh Moftakhar