Dear GAP Forum I would like to compute the maximal set of pairwise non commuting elements in a finite groups. Of course i can find the following program which work through a grahp but i do not understand how it work. I will be more grateful for any help or comments. best regards
LoadPackage("grape"); N:=function(a,b) return(IsAbelian(Group(a,b))); end; NonCommutingGraph:=function(g) local k, x, y; k:=Graph(g,Difference(g,Center(g)),OnPoints,function(x,y) return N(x,y)=false;end); return k; end; clique:=function(x) local G1,G2; G1:=NonCommutingGraph(x); G2:=ComplementGraph(G1); return Size(IndependentSet(G2)); end; CliqueNumber:=function(x) local c, t, M; c:=clique(x); while c>0 do t:=c; M:=CompleteSubgraphsOfGivenSize(NonCommutingGraph(x),c+1,0); c:=Size(M); if c=0 then return(t); fi; od; end; _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum