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O IS NOT ENOUGH

Published online by Cambridge University Press:  09 July 2009

J. B. PARIS*
Affiliation:
School of Mathematics, University of Manchester
R. SIMMONDS*
Affiliation:
School of Mathematics, University of Manchester
*
*SCHOOL OF MATHEMATICS, UNIVERSITY OF MANCHESTER, MANCHESTER M13 9PL, UK. E-mail:[email protected]
SCHOOL OF MATHEMATICS, UNIVERSITY OF MANCHESTER, MANCHESTER M13 9PL, UK. E-mail:[email protected]

Abstract

We examine the closure conditions of the probabilistic consequence relation of Hawthorne and Makinson, specifically the outstanding question of completeness in terms of Horn rules, of their proposed (finite) set of rules O. We show that on the contrary no such finite set of Horn rules exists, though we are able to specify an infinite set which is complete.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2009

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References

BIBLIOGRAPHY

Farkas, J. (1902). Theorie der Einfachen Ungleichungen. Journal für die Reine und Angewandte Mathematik, 124, 127.Google Scholar
Hawthorne, J. (1996). On the logic on non-monotonic conditionals and conditional probabilies. Journal of Philosophical Logic, 25, 185218.CrossRefGoogle Scholar
Hawthorne, J. (2007). Nonmonotonic conditionals that behave like conditional probabilities above a threshold. Journal of Applied Logic, 5, 625637.CrossRefGoogle Scholar
Hawthorne, J., & Makinson, D. (2007). The qualitative/quantitative watershed for rules of uncertain inference. Studia Logica, 86, 247297.CrossRefGoogle Scholar
Krauss, S., Lehmann, D., & Magidor, M. (1990). Nonmonotonic reasoning, preferential models and cumulative logics. Artificial Intelligence, 44, 167207.CrossRefGoogle Scholar
Lehmann, D., & Magidor, M. (1992). What does a conditional knowledge base entail? Artificial Intelligence, 55, 160.CrossRefGoogle Scholar
Makinson, D. (1994). General patterns in nonmontonic reasoning. In Gabbay, , Hogger, , and Robinson, , editors. Handbook of Logic in Artificial Intelligence and Logic Programming, Vol. 3. Oxford: Clarendon Press, pp. 35110.CrossRefGoogle Scholar
Marker, D. (2002). Model Theory: An Introduction. Graduate Texts in Mathematics, Vol. 217. New York: Springer-Verlag.Google Scholar
Pillay, A. (1981). Models of Peano Arithmetic, In editors Berline, , McAloon, , and Ressayre, , editors. Model Theory and Arithmetic, Lecture Notes in Mathematics, Vol. 890. Berlin: Springer-Verlag, pp. 112.CrossRefGoogle Scholar
Simmonds, R. (2009). On Horn Closure Conditions for Probabilistic Consequence Relations, University of Manchester. Available from: http://www.maths.manchester.ac.uk/~jeff/Google Scholar