Britz, KatarinaVarzinczak, Ivan J2019-04-022019-04-022018-04Britz, K. and Varzinczak, I. 2018. Rationality and context in defeasible subsumption. Foundations of Information and Knowledge Systems, pp. 114-132978-3-319-90049-0https://link.springer.com/chapter/10.1007/978-3-319-90050-6_7DOI: https://doi.org/10.1007/978-3-319-90050-6_7http://hdl.handle.net/10204/10895This is the accepted version of the published chapter. The published version cab be obtained via the publisher's website: https://link.springer.com/chapter/10.1007/978-3-319-90050-6_7Description logics have been extended in a number of ways to support defeasible reasoning in the KLM tradition. Such features include preferential or rational defeasible concept subsumption, and defeasible roles in complex concept descriptions. Semantically, defeasible subsumption is obtained by means of a preference order on objects, while defeasible roles are obtained by adding a preference order to role interpretations. In this paper, we address an important limitation in defeasible extensions of description logics, namely the restriction in the semantics of defeasible concept subsumption to a single preference order on objects. We do this by inducing a modular preference order on objects from each preference order on roles, and use these to relativise defeasible subsumption. This yields a notion of contextualised rational defeasible subsumption, with contexts described by roles. We also provide a semantic construction for and a method for the computation of contextual rational closure, and present a correspondence result between the two.enContextual defeasibilityRational entailmentDefeasible subsumptionBook ChapterBritz, K., & Varzinczak, I. J. (2018). Rationality and context in defeasible subsumption., <i>Worklist;22129</i> Springer. http://hdl.handle.net/10204/10895Britz, Katarina, and Ivan J Varzinczak. "Rationality and context in defeasible subsumption" In <i>WORKLIST;22129</i>, n.p.: Springer. 2018. http://hdl.handle.net/10204/10895.Britz K, Varzinczak IJ. Rationality and context in defeasible subsumption.. Worklist;22129. [place unknown]: Springer; 2018. [cited yyyy month dd]. http://hdl.handle.net/10204/10895.TY - Book Chapter AU - Britz, Katarina AU - Varzinczak, Ivan J AB - Description logics have been extended in a number of ways to support defeasible reasoning in the KLM tradition. Such features include preferential or rational defeasible concept subsumption, and defeasible roles in complex concept descriptions. Semantically, defeasible subsumption is obtained by means of a preference order on objects, while defeasible roles are obtained by adding a preference order to role interpretations. In this paper, we address an important limitation in defeasible extensions of description logics, namely the restriction in the semantics of defeasible concept subsumption to a single preference order on objects. We do this by inducing a modular preference order on objects from each preference order on roles, and use these to relativise defeasible subsumption. This yields a notion of contextualised rational defeasible subsumption, with contexts described by roles. We also provide a semantic construction for and a method for the computation of contextual rational closure, and present a correspondence result between the two. DA - 2018-04 DB - ResearchSpace DP - CSIR KW - Contextual defeasibility KW - Rational entailment KW - Defeasible subsumption LK - https://researchspace.csir.co.za PY - 2018 SM - 978-3-319-90049-0 T1 - Rationality and context in defeasible subsumption TI - Rationality and context in defeasible subsumption UR - http://hdl.handle.net/10204/10895 ER -