gap> gamma:=PrincipalCongruenceSubgroup(5);; #using Congruence package
gap> gens:=GeneratorsOfGroup(gamma);;
#I  Using the Congruence package for GeneratorsOfGroup ...
gap> List(gens,Order);
[ infinity, infinity, infinity, infinity, infinity, infinity, infinity, 
  infinity, infinity, infinity, infinity ]

gap> gamma:=CongruenceSubgroupGamma0(13);; #using Congruence package
gap> gens:=GeneratorsOfGroup(gamma);;
#I  Using the Congruence package for GeneratorsOfGroup ...
gap> List(gens,Order);
[ infinity, 3, 4, 4, 3 ]
