Constraint Logic Programming - a Framework for Qualitative Reasoning

We propose to use Constraint Logic Programming (CLP) for the specification and implementation of Qualitative Reasoning (QR) problems that are specialized Constraint Satisfaction Problems . The use of CLP has two advantages : (i) CLP gives a well defined and understood logical framework for the problem specification, and (ii) CLP is not only a logical framework, it is also a family oflanguages specially developed for solving classes of CSP problems . Thus we obtain a class of powerful implementation languages for rapid prototyping . To illustrate the steps of specification and implementation we describe in detail the core of the QSIM algorithm (Kuipers 1994), namely the filtering of the state transitions in the CLP framework . We show how the basic constraints are specified in this framework and describe the technical aspects of an implementation . We want to demonstrate the advantages of CLP through an example for a large and complex qualitative reasoning algorithm .