KR2023Proceedings of the 20th International Conference on Principles of Knowledge Representation and ReasoningProceedings of the 20th International Conference on Principles of Knowledge Representation and Reasoning

Rhodes, Greece. September 2-8, 2023.

Edited by
  1. Pierre Marquis,
  2. Tran Cao Son
  3. Gabriele Kern-Isberner

ISSN: 2334-1033
ISBN: 978-1-956792-02-7

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Published by

Copyright © 2023 International Joint Conferences on Artificial Intelligence Organization

Querying Circumscribed Description Logic Knowledge Bases

  1. Carsten Lutz(Department of Computer Science, Leipzig University, Germany)
  2. Quentin Manière(Department of Computer Science, Leipzig University, Germany, Center for Scalable Data Analytics and Artificial Intelligence (ScaDS.AI), Dresden/Leipzig, Germany)
  3. Robin Nolte(University of Bremen, Digital Media Lab, Germany)
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BibTeX
https://doi.org/10.24963/kr.2023/47

Keywords

  1. Description logics
  2. Nonmonotonic logics, default logics, conditional logics

Abstract

Circumscription is one of the main approaches for defining non-monotonic description logics (DLs) and the decidability and complexity of traditional reasoning tasks, such as satisfiability of circumscribed DL knowledge bases (KBs) are well understood. For evaluating conjunctive queries (CQs) and unions thereof (UCQs), in contrast, not even decidability had been established. In this paper, we prove decidability of (U)CQ evaluation on circumscribed DL KBs and obtain a rather complete picture of both the combined complexity and the data complexity, for DLs ranging from ALCHIO via EL to various versions of DL-Lite. We also study the much simpler atomic queries (AQs).