The QAT: A Qualitative Algebra Toolkit

Representing and reasoning about spatial and temporal information is an important task in many applications of artificial intelligence. In the past two decades numerous formalisms have been proposed for representing and reasoning about time and space using qualitative constraints. In the first part of this paper we propose and study a general definition of such formalisms by considering calculi based on basic relations of an arbitrary arity. In a second part we describe the QAT (qualitative algebra toolkit), a Java constraint programming library allowing to handle constraint networks based on those qualitative calculi. The main motivation of this work stems from the fact that most software tools dealing with qualitative calculi have only been implemented for specific qualitative calculi