Tractable Reasoning and Conjunctive Query Answering for Defeasible DL-Lite under Rational Closure

Computer Science > Artificial Intelligence [Submitted on 23 Jun 2026] Tractable Reasoning and Conjunctive Query Answering for Defeasible DL-Lite under Rational Closure Giovanni Casini (1 and 2), Umberto Straccia (1) ((1) CNR - ISTI, (2) University of Cape Town) In Description Logics (DLs), reasoning under Rational Closure (RC) is a well-known and widely accepted non-monotonic formalism to handle defeasible knowledge. In this paper, we study the application of RC to the core and horn variants of the DL-Lite family of lightweight description logics. We analyze both entitlement (instance checking) and Conjunctive Query (CQ) answering under RC. Our main contribution is providing a plug-in architecture that builds upon existing standard classical reasoners, establishing that reasoning and CQ answering under RC for DL-Lite can be done efficiently with minimal computational overhead. Comments: 108 pages, 2 figures, 1 table Subjects: Artificial Intelligence (cs.AI) ACM classes: I.2.4; F.4.1 Cite as: arXiv:2606.24279 [cs.AI]   (or arXiv:2606.24279v1 [cs.AI] for this version)   https://doi.org/10.48550/arXiv.2606.24279 Focus to learn more Submission history From: Giovanni Casini [view email] [v1] Tue, 23 Jun 2026 08:02:07 UTC (672 KB) Access Paper: view license Current browse context: cs.AI < prev   |   next > new | recent | 2026-06 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)