“…Then the cartesian product dimap h = f x g : D 1 x D 2 D 1 x D 2 is defined as follows: h{(u 4 ,v 2 ),(u 3 ,v 1 )}={(u 2 ,v 2 ),(u 3 ,v 3 )}, and so on. Also, h{((u4,v2),(u1,v2)), ((u3,v1),(u3,v2))}= {((u2,v2),(u1,v2)), ((u3,v3),(u3,v2))}, and so on, see Figure 6.…”