DFKI-LT - A Temporal Extension of the Hayes/ter Horst Entailment Rules and an Alternative to W3C's N-ary Relations
A Temporal Extension of the Hayes/ter Horst Entailment Rules and an Alternative to W3C's N-ary Relations
1 7th International Conference on Formal Ontology in Information Systems, Graz, Austria, IOS Press, 2012
Temporal encoding schemes using RDF and OWL are often plagued by a massive proliferation of useless "container" objects. Reasoning and querying with such representations is extremely complex, expensive, and error-prone. We present a temporal extension of the Hayes and ter Horst entailment rules for RDFS (Hayes, 2004) and OWL (ter Horst, 2005) which apply to the TBox, RBox, and ABox of an ontology in order to make implicit knowledge explicit. The extension requires only some lightweight forms of reasoning and is realized by adding two further temporal arguments, thus replacing a triple by a quintuple. The approach has been implemented in the forward chaining engine HFC. Our decision was motivated by experiences we have gained in former projects that have dealt with the representation of changing information over time in description logic ontologies. In order to verify the superiority of the approach, we compare the quintuple-based approach with a semantic-preserving encoding scheme for N-ary relations in RDF triples, as proposed by the Semantic Web Best Practices Group of the W3C. The comparison is carried out on a theoretical as well as on a practical level, both in the space and the time domain when computing the deductive closure w.r.t. the triple- and quintuple-based temporal entailment rules.