Detail

NoHR – Querying EL Ontologies and Non-Monotonic Rules

In this talk, we present a plug-in for the ontology editor Protégé called NoHR that allows the user to take an EL ontology, add a set of non-monotonic (logic programming) rules – suitable e.g. to express defaults and exceptions – and query the combined knowledge base. The tool itself builds on the procedure SLG(O) and, with the help of OWL 2 EL reasoner ELK, pre-processes the ontology into rules, whose result together with the non-monotonic rules serve as input for the top- down querying engine XSB Prolog. With the resulting Protégé plug-in, the first of its kind, even queries to very large ontologies, such as SNOMED CT, augmented with a large number of rules, can be processed at an interactive response time after one initial brief pre-processing period.