Casini, GMeyer, TMoodley, KNortjé, R2015-10-152015-10-152014-09Casini, G, Meyer, T, Moodley, K and Nortjé, R. 2014. Relevant closure: a new form of defeasible reasoning for description logics. In: 14th European Conference on Logics in Artificial Intelligence JELIA, Madeira, Spain, 24-26 September 2014978-3-319-11557-3http://link.springer.com/chapter/10.1007%2F978-3-319-11558-0_7http://hdl.handle.net/10204/819214th European Conference on Logics in Artificial Intelligence JELIA, Madeira, Spain, 24-26 September 2014Among the various proposals for defeasible reasoning for description logics, Rational Closure, a procedure originally defined for propositional logic, turns out to have a number of desirable properties. Not only it is computationally feasible, but it can also be implemented using existing classical reasoners. One of its drawbacks is that it can be seen as too weak from the inferential point of view. To overcome this limitation we introduce in this paper two extensions of Rational Closure: Basic Relevant Closure and Minimal Relevant Closure. As the names suggest, both rely on defining a version of relevance. Our formalisation of relevance in this context is based on the notion of a justification (a minimal subset of sentences implying a given sentence). This is, to our knowledge, the first proposal for defining defeasibility in terms of justifications—a notion that is well-established in the area of ontology debugging. Both Basic and Minimal Relevant Closure increase the inferential power of Rational Closure, giving back intuitive conclusions that cannot be obtained from Rational Closure. We analyse the properties and present algorithms for both Basic and Minimal Relevant Closure, and provide experimental results for both Basic Relevant Closure and Minimal Relevant Closure, comparing it with Rational Closure.enRational closureDescription logicsArtificial intelligenceConference PresentationCasini, G., Meyer, T., Moodley, K., & Nortjé, R. (2014). Relevant closure: a new form of defeasible reasoning for description logics. Springer International Publishing. http://hdl.handle.net/10204/8192Casini, G, T Meyer, K Moodley, and R Nortjé. "Relevant closure: a new form of defeasible reasoning for description logics." (2014): http://hdl.handle.net/10204/8192Casini G, Meyer T, Moodley K, Nortjé R, Relevant closure: a new form of defeasible reasoning for description logics; Springer International Publishing; 2014. http://hdl.handle.net/10204/8192 .TY - Conference Presentation AU - Casini, G AU - Meyer, T AU - Moodley, K AU - Nortjé, R AB - Among the various proposals for defeasible reasoning for description logics, Rational Closure, a procedure originally defined for propositional logic, turns out to have a number of desirable properties. Not only it is computationally feasible, but it can also be implemented using existing classical reasoners. One of its drawbacks is that it can be seen as too weak from the inferential point of view. To overcome this limitation we introduce in this paper two extensions of Rational Closure: Basic Relevant Closure and Minimal Relevant Closure. As the names suggest, both rely on defining a version of relevance. Our formalisation of relevance in this context is based on the notion of a justification (a minimal subset of sentences implying a given sentence). This is, to our knowledge, the first proposal for defining defeasibility in terms of justifications—a notion that is well-established in the area of ontology debugging. Both Basic and Minimal Relevant Closure increase the inferential power of Rational Closure, giving back intuitive conclusions that cannot be obtained from Rational Closure. We analyse the properties and present algorithms for both Basic and Minimal Relevant Closure, and provide experimental results for both Basic Relevant Closure and Minimal Relevant Closure, comparing it with Rational Closure. DA - 2014-09 DB - ResearchSpace DP - CSIR KW - Rational closure KW - Description logics KW - Artificial intelligence LK - https://researchspace.csir.co.za PY - 2014 SM - 978-3-319-11557-3 T1 - Relevant closure: a new form of defeasible reasoning for description logics TI - Relevant closure: a new form of defeasible reasoning for description logics UR - http://hdl.handle.net/10204/8192 ER -