A formal theory for reasoning about parthood, connection, and location

In fields such as medicine, geography, and mechanics, spatial reasoning involves reasoning about entities that may coincide without overlapping. Some examples are: cavities and invading particles, passageways and valves, geographic regions and tropical storms. The purpose of this paper is to develop a formal theory of spatial relations for domains that include coincident entities. The core of the theory is a clear distinction between mereotopological relations, such as parthood and connection, and relative location relations, such as coincidence. To guide the development of the formal theory, I construct mathematical models in which nontrivial relative location relations are defined.  2004 Elsevier B.V. All rights reserved.