A Spatial Logic based on Regions and Connection.

We describe an interval logic for reasoning about space. The logic simplifies an earlier theory developed by Randell and Cohn, and that of Clarke upon which the former was based. The theory supports a simpler ontology, has fewer defined functions and relations, yet does not suffer in terms of its useful expressiveness. An axiomatisation of the new theory and a comparison with the two original theories is given. 1 Introduction The use of interval logics for the representation of time are well known in AI research - see for example Allen (1984) and Allen and Hayes (1985) although their development and history extends back much further in philosophical literature, see for example Hamblin (1967, 1971). However, despite the intuitive connection that can be drawn between space and time in terms of such logics, until fairly recently, little work in AI has centred on the development and use of interval logics for space. We describe an interval logic that can be used to reason about...