Region Connection Calculus 4


Region Connection Calculus (RCC) [1] [2] is intended to serve for qualitative spatial representation and reasoning. RCC abstractly describes regions (in Euclidean space, or in a topological space) by their possible relations to each other.

RCC4 consists of 4 basic relations that are possible between two regions; it is a stripped down version of RCC8. The mapping from RCC8 to RCC4 can be seen below:

dc dc
ec po
tpp pp
tppi ppi


All the possible RCC4 relations between a blue object X and a red object Y are:

Relation Illustration Interpretation
X dc Y ../../../_images/rcc8_dc.png X is disconnected from Y.
X po Y ../../../_images/rcc8_ec.png X is partially overlapping Y.
X pp Y ../../../_images/rcc8_tpp.png X is a proper part of Y.
X ppi Y ../../../_images/rcc8_tppi.png X is a proper part inverse of Y.


The API can be found here.


[1]Randell, D. A., Cui, Z. and Cohn, A. G.: A spatial logic based on regions and connection, Proc. 3rd Int. Conf. on Knowledge Representation and Reasoning, Morgan Kaufmann, San Mateo, pp. 165–176, 1992. (link)
[2]Anthony G. Cohn, Brandon Bennett, John Gooday, Micholas Mark Gotts: Qualitative Spatial Representation and Reasoning with the Region Connection Calculus. GeoInformatica, 1, 275–316, 1997.