A necessary relation algebra for mereotopology

Title:	A necessary relation algebra for mereotopology
Authors:	Ivo Düntsch , Dept of Computer Science , Brock University , St Catherines, Ontario, L2S 3A1, Canada Gunther Schmidt, Michael Winter, Department of Computer Science, University of the Federal Armed Forces Munich, 85577 Neubiberg, Germany
Status:	To appear in Studia Logica
Abstract:	We show that the basis operations of the relational calculus on a ``contact relation'' generate at least 25 relations in any model of the Region Connection Calculus, and interpret these relations in the collection of regular open sets in the two-dimensional Euclidean plane.