gap> Q:=QuadraticNumberField(-1);;
gap> Lfunction(Q,2)/(18*3.142);
0.0161957

Loge10:=0.434294481903;; #Log_10(e)
gap> 1.0*Log(Product(AbelianInvariants(G)),10)/(Loge*Norm(I));
0.0210325
