Subject: to post a message Date: Fri, 31 Jan 2003 17:35:50 -0500 From: "Jorge Alberto Borrego Morell" To: Hello. I neeed information about some result concerning the relationship between surfaces non manifolds and manifolds, for example, Is a surface non manifold a kind of union of manifolds?. It is known that any polygon (when I say polygon I refer to every figure homeomorphic to it) is a union of simple polygons or polygons with simple holes so that each of them has a point in common or void intersection. This results has some conection with the answer above?. A combinatorial manifold is related to this question?. If this is the case could you give me some definition of this concept. I would be very gratefull if you help me with this