Dear Sir/Madam, I am a beginner of GAP and would like to use this program to determine the structure of some groups. Here is the group I am interested in :
Let K_3 be the group generated by three elements a, b, c subject to the relation that every simple commutator with repeated generators is equal to 1. (For example, [[[a, c], b], c] = 1.) Now let A_3 be the subgroup of K_3 generated by abc, [a, b][b, c][a, c], [[a, b], c] and [[a, c], b] and I would like to determine the structure of abelianization of A_3. Here is my code: F3:=FreeGroup("a","b","c"); B3:=[Comm(Comm(F3.1,F3.2),F3.1),Comm(Comm(F3.1,F3.2),F3.2),Comm(Comm(F3.2,F3.3),F3.2),Comm(Comm(F3.2,F3.3),F3.3),Comm(Comm(F3.1,F3.3),F3.1),Comm(Comm(F3.1,F3.3),F3.3),Comm(Comm(Comm(F3.1,F3.2),F3.3),F3.1),Comm(Comm(Comm(F3.1,F3.3),F3.2),F3.1),Comm(Comm(Comm(F3.2,F3.1),F3.3),F3.1),Comm(Comm(Comm(F3.2,F3.3),F3.1),F3.1),Comm(Comm(Comm(F3.3,F3.1),F3.2),F3.1),Comm(Comm(Comm(F3.3,F3.2),F3.1),F3.1),Comm(Comm(Comm(F3.1,F3.2),F3.3),F3.2),Comm(Comm(Comm(F3.1,F3.3),F3.2),F3.2),Comm(Comm(Comm(F3.2,F3.1),F3.3),F3.2),Comm(Comm(Comm(F3.2,F3.3),F3.1),F3.2),Comm(Comm(Comm(F3.3,F3.1),F3.2),F3.2),Comm(Comm(Comm(F3.3,F3.2),F3.1),F3.2),Comm(Comm(Comm(F3.1,F3.2),F3.3),F3.3),Comm(Comm(Comm(F3.1,F3.3),F3.2),F3.3),Comm(Comm(Comm(F3.2,F3.1),F3.3),F3.3),Comm(Comm(Comm(F3.2,F3.3),F3.1),F3.3),Comm(Comm(Comm(F3.3,F3.1),F3.2),F3.3),Comm(Comm(Comm(F3.3,F3.2),F3.1),F3.3),]; K3:=F3/B3; a:=K3.1; b:=K3.2; c:=K3.3; A3:=Subgroup(K3,[a*b*c,Comm(a,b)*Comm(a,c)*Comm(b,c),Comm(Comm(a,b),c), Comm(Comm(a,c),b)]); But when I run the command AbelianInvariants(A3), the following error message appeared: Error, the coset enumeration has defined more than 4096000 cosets called from TCENUM.CosetTableFromGensAndRels( fgens, grels, fsgens ) called from CosetTableFromGensAndRels( fgens, grels, fsgens ) called from TryCosetTableInWholeGroup( H ) called from CosetTableInWholeGroup( H ) called from RelatorMatrixAbelianizedSubgroupRrs( G, H ) called from ... at line 66 of *stdin* type 'return;' if you want to continue with a new limit of 8192000 cosets, type 'quit;' if you want to quit the coset enumeration, type 'maxlimit := 0; return;' in order to continue without a limit I thought it was because my groups are too complicated for GAP and thus I tried a much simpler version of groups: F2:=FreeGroup("a","b"); B2:=[Comm(Comm(F2.1,F2.2),F2.1),Comm(Comm(F2.1,F2.2),F2.2)]; K2:=F2/B2; A2:=Subgroup(K2,[K2.1*K2.2,Comm(K2.1,K2.2)]) * * When I run the command AbelianInvariants(A2), the same error message appeared. As I urgently need to do these calculations, any assistance/advice will be greatly appreciated. By the way, this is the first time that I write to this forum; please forgive me if there is anything improper in my question. Many thanks and best regards, MH _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum