Mereotopology

Synonyms

4-Intersection calculus; 9-Intersection calculus; Pointless topology; RCC; Region connection calculus

Definition

Topology, which is founded on the notion of connectedness, is at the heart of many systems of qualitative spatial relations; since it is possible to define a notion of parthood from connection, and theories of parthood are called mereologies, such combined theories are generally called mereotopologies. The best known set of relations based on a primitive notion of connectedness is the Region Connection Calculus (RCC), which defines several sets of jointly exhaustive and pairwise disjoint, (JEPD) relations, RCC-5, a purely mereological set, and the more widely used RCC-8 set of eight relations illustrated in Fig. 1. The primitive relation used in RCC (and several related theories) is C(x, y) – true when region x is connected to region y. A largely equivalent set of relations can be defined in the 4-intersection model in which relations between regions are defined in...