Abstract
We introduce new concepts for default reasoning in the context of query-answering in regular default logic. For this purpose, we develop a proof-oriented approach for deciding whether a default theory has an extension containing a given query. The inherent problem in Reiter’s default logic is that it necessitates the inspection of all default rules for answering no matter what query. Also, default theories are known to lack extensions occasionally. We address these two problems by sloting in a compilation phase before the actual query-answering phase. The examination of the entire set of default rules is then done only once in the compilation phase; this allows us to inspect only the ultimately necessary default rules during the actual query answering phase. In fact, the latter inspection must not only account for the derivability of the query, but moreover it must guarantee the existence of an encompassing extension. We address this traditionally important problem by furnishing novel criteria guaranteeing the existence of extensions that are arguably simpler and go well beyond existing approaches.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
G. Brewka. Nonmonotonic Reasoning: Logical Foundations of Commonsense. Cambridge University Press, Cambridge, 1991.
P. Cholewiński. Reasoning with stratified default theories. In Proc. Third International Conf. on Logic Programming and Nonmonotonic Reasoning, 1995.
P. Cholewiński, V. Marek, and M. Truszczyński. Default reasoning system DeReS. In Proc. Fifth International Conf. on the Principles of Knowledge Representation and Reasoning. Morgan Kaufmann, 1996.
D. Etherington. Reasoning with Incomplete Information. Research Notes in AI, Pitman.
D. Etherington. Formalizing nonmonotonic reasoning. Artificial Intelligence, 31:41–85, 1987.
G. Gottlob. Complexity results for nonmonotonic logics. J. Logic and Computation, 2(3):397–425, June 1992.
U. Junker and K. Konolige. Computing the extensions of autoepistemic and default logic with a TMS. In Proc. AAAI National Conf. on Artificial Intelligence, 1990.
W. Marek and M. Truszczyński. Nonmonotonic logic: context-dependent reasoning. Artifical Intelligence. Springer, 1993.
I. Niemelä. Towards efficient default reasoning. In Proc. International Joint Conf. on Artificial Intelligence, 312–318. Morgan Kaufmann, 1995.
C. Papadimitriou and M. Sideri. Default theories that always have extensions. Artificial Intelligence, 69:347–357, 1994.
R. Reiter. A logic for default reasoning. Artificial Intelligence, 13(1–2):81–132, 1980.
T. Schaub. A new methodology for query-answering in default logics via structure-oriented theorem proving. J. Automated Reasoning, 15(1):95–165, 1995.
G. Schwarz and M. Truszczyński. Subnormal modal logics for knowledge representation. In Proc. AAAI National Conf. on Artificial Intelligence, 438–443. Morgan Kaufmann, 1993.
C. Schwind and V. Risch. Tableau-based characterization and theorem proving for default logic. J. Automated Reasoning, 13:223–242, 1994.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1998 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Linke, T., Schaub, T. (1998). An Approach to Query-Answering in Reiter’s Default Logic and the Underlying Existence of Extensions Problem. In: Dix, J., del Cerro, L.F., Furbach, U. (eds) Logics in Artificial Intelligence. JELIA 1998. Lecture Notes in Computer Science(), vol 1489. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-49545-2_16
Download citation
DOI: https://doi.org/10.1007/3-540-49545-2_16
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-65141-3
Online ISBN: 978-3-540-49545-1
eBook Packages: Springer Book Archive