gap> P:=ClosedSurface(-1);;
gap> P:=SimplifiedComplex(RegularCWComplex(P));;
gap> PP:=DirectProduct(P,P);;
gap> SPP:=Suspension(PP);
Regular CW-complex of dimension 5

gap> A:=CohomologyRing(SPP,2);
&lt;algebra of dimension 9 over GF(2)&gt;
gap> List(Basis(A),x->Bockstein(A,x));          
[ 0*v.1, v.5, v.6, v.7+v.8, 0*v.1, 0*v.1, v.9, v.9, 0*v.1 ]
