Adding Convexity to Mereotopology

Convexity predicates and the convex hull operator continue to play an important role in theories of spatial representation and reasoning, yet their firstorder axiomatization is still a matter of controversy. In this paper, we present a new approach to adding convexity to a mereotopological theory with boundary elements by specifying first-order axioms for a binary segment operator s. We show that our axioms yield a convex hull operator h that supports, not only the basic properties of convex regions, but also complex properties concerning region alignment. We also argue that h is stronger than convex hull operators from existing axiomatizations and show how to derive the latter from our axioms for s. Final version published in Pawel Garbacz and Oliver Kutz (eds.), Formal Ontology in Information Systems. Proceedings of the Eighth International Conference, Amsterdam, IOS Press, 2014, pp. 65–78.