Skip to main content

Nonmonotonic reasoning is sometimes simpler

  • Contributed Papers
  • Conference paper
  • First Online:
Computational Logic and Proof Theory (KGC 1993)

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 713))

Included in the following conference series:

Abstract

We establish the complexity of decision problems associated with the nonmonotonic modal logic S4. We prove that the problem of existence of an S4-expansion for a given set A of premises is Σ P2 -complete. Similarly, we show that for a given formula ϕ and a set A of premises, it is Σ P2 -complete to decide whether ϕ belongs to at least one S4-expansion for A, and it is Π P2 -complete to decide whether ϕ belongs to all S4-expansions for A. An interesting aspect of these results is that reasoning (testing satisfiability and provability) in the monotonic modal logic S4 is PSPACE-complete. To the best of our knowledge, the nonmonotonic logic S4 is the first example of a nonmonotonic formalism which is computationally easier than the monotonic logic that underlies it (assuming PSPACE does not collapse to Σ 2)P .

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. T. Eiter and G. Gottlob. Propositional circumscription and extended closed world reasoning are Π2/p-complete. To appear in Theoretical Comp. Sci.

    Google Scholar 

  2. T. Eiter and G. Gottlob. Complexity of reasoning with parsimonious and moderately grounded expansions. Fundamenta Informaticae, 17, 31–53, 1992.

    Google Scholar 

  3. M.R. Garey and D.S. Johnson. Computers and Intractability; a guide to the theory of NP-completeness. W.H. Freeman, 1979.

    Google Scholar 

  4. G. Gottlob. Complexity results for nonmonotonic logics. Journal of Logic and Computation, 2:397–425, 1992.

    Google Scholar 

  5. G.E. Hughes and M.J. Cresswell. A companion to modal logic. Methuen and Co. Ltd., London, 1984.

    Google Scholar 

  6. J.Y. Halpern and Y. Moses. A guide to modal logics of knowledge and belief. In Proceedings of the Ninth International Joint Conference on Artificial Intelligence, pages 480–490. Morgan Kaufmann, 1985.

    Google Scholar 

  7. R. Ladner. The computational complexity of provability in systems of modal propositional logic. SIAM J. Comp., 6:467–480, 1977.

    Google Scholar 

  8. W. Lenzen. Recent Work in Epistemic Logic, volume 30 of Acta Philosophica Fennica. North-Holland, Amsterdam, 1978.

    Google Scholar 

  9. W. Lenzen. Epistemologische Betrachtungen zu [S4, S5]. Erkenntnis, 14:33–56, 1979.

    Google Scholar 

  10. J. McCarthy. Circumscription — a form of non-monotonic reasoning. Artificial Intelligence, 13:27–39, 1980.

    Google Scholar 

  11. D. McDermott. Nonmonotonic logic II: Nonmonotonic modal theories. Journal of the ACM, 29:33–57, 1982.

    Google Scholar 

  12. D. McDermott and J. Doyle. Nonmonotonic logic I. Artificial Intelligence, 13:41–72, 1980.

    Google Scholar 

  13. R.C. Moore. Semantical considerations on non-monotonic logic. Artificial Intelligence, 25:75–94, 1985.

    Google Scholar 

  14. W. Marek, G.F. Shvarts, and M. Truszczyński. Modal nonmonotonic logics: ranges, characterization, computation. In Second International Conference on Principles of Knowledge Representation and Reasoning, KR '91, pages 395–404, San Mateo, CA., 1991. Morgan Kaufmann. An extended version of this article will appear in the Journal of the ACM.

    Google Scholar 

  15. W. Marek and M. Truszczyński. Nonmonotonic Logics; Context-Dependent Reasoning. Springer-Verlag, 1993. To appear.

    Google Scholar 

  16. I. Niemelä. On the decidability and complexity of autoepistemic reasoning. Fundamenta Informaticae, 17:117–155, 1992.

    Google Scholar 

  17. R. Reiter. A logic for default reasoning. Artificial Intelligence, 13:81–132, 1980.

    Google Scholar 

  18. K. Segerberg. An essay in classical modal logic. Uppsala University, Filosofiska Studier, 13, 1971.

    Google Scholar 

  19. G.F. Shvarts. Autoepistemic modal logics. In R. Parikh, editor, Proceedings of TARK 1990, pages 97–109, San Mateo, CA., 1990. Morgan Kaufmann.

    Google Scholar 

  20. G.F. Schwarz and M. Truszczyński. Modal logic S4F and the minimal knowledge paradigm. In Y. Moses, editor, Proceedings of TARK 1992, pages 184–198, San Mateo, CA., 1992. Morgan Kaufmann.

    Google Scholar 

  21. G.F. Schwarz and M. Truszczyński. Subnormal modal logics for knowledge representation. In Proceedings of AAAI-93. To appear.

    Google Scholar 

  22. M. Tiomkin and M. Kaminski. Nonmonotonic default modal logics. Journal of the ACM, 38:963–984, 1991.

    Google Scholar 

  23. M. Truszczyński. Modal interpretations of default logic. In Proceedings of IJCAI-91, pages 393–398, San Mateo, CA., 1991. Morgan Kaufmann.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Georg Gottlob Alexander Leitsch Daniele Mundici

Rights and permissions

Reprints and permissions

Copyright information

© 1993 Springer-Verlag Berlin Heidelberg

About this paper

Cite this paper

Schwarz, G., Truszczyński, M. (1993). Nonmonotonic reasoning is sometimes simpler. In: Gottlob, G., Leitsch, A., Mundici, D. (eds) Computational Logic and Proof Theory. KGC 1993. Lecture Notes in Computer Science, vol 713. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0022579

Download citation

  • DOI: https://doi.org/10.1007/BFb0022579

  • Published:

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-57184-1

  • Online ISBN: 978-3-540-47943-7

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics