gap> G:=R!.group;;
gap> gensG:=GeneratorsOfGroup(G);;
gap> W:=CoxeterDiagramMatCoxeterGroup(D);;
gap> gensW:=GeneratorsOfGroup(W);;
gap> rho:=GroupHomomorphismByImages(G,W,gensG,gensW);;
gap> C:=HomToIntegralModule(R,rho);;
gap> Cohomology(C,6);
[ 2, 2, 2, 2, 2, 2 ]
