my_model(x[3], a[1])
{
array center[3];
center = [4,4,0];
tr1=hfTorusZ(x,center,4.6,1.4);

center[2]=-2.5;
tr2=hfTorusX(x,center,5,1.5); 

center[1]=-2.; center[2]=5.5;
tr3=hfTorusY(x,center,4.8,1.2);

my_model = tr1 | tr2 | tr3;
}