Using Prolog Unification to Solve Non-standard Reasoning Problems in Description Logics

We present a Logic Programming prototype implementation working as proof-of-concept for a unified strategy proposed in our past research to solve several non-standard reasoning problems in Description Logics (DLs) and denoted by Constructive Reasoning. In order to proof both the problem-independence and the logic-independence of the adopted approach, the prototype is focused on the solution of three different problems— namely Least Common Subsumer, Concept Abduction and Concept Difference– and two different, though simple, DLs, i.e., EL and ALN . Accordingly to the implemented strategy, problems are formalized as conjunction of both subsumption and non-subsumption statements, causing the whole prototype to rely on a Prolog program solving subsumption. The program is built around a predicate, which on the one hand checks for the existence of subsumption relations between ground elements, providing boolean answers, and on the other hand, if inverted, exploits Prolog built-in unification to enumerate variable values making subsumption true between concept terms containing concept variables.