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QUANTIFIED LOGIC OF AWARENESS AND IMPOSSIBLE POSSIBLE WORLDS

Published online by Cambridge University Press:  01 December 2008

GIACOMO SILLARI*
Affiliation:
Philosophy, Politics, and Economics Program, University of Pennsylvania
*
*PHILOSOPHY, POLITICS, AND ECONOMICS PROGRAM UNIVERSITY OF PENNSYLVANIA 313 CLAUDIA COHEN HALL PHILADELPHIA, PA 19104 E-mail:[email protected]

Abstract

Among the many possible approaches to dealing with logical omniscience, I consider here awareness and impossible worlds structures. The former approach, pioneered by Fagin and Halpern, distinguishes between implicit and explicit knowledge, and avoids logical omniscience with respect to explicit knowledge. The latter, developed by Rantala and by Hintikka, allows for the existence of logically impossible worlds to which the agents are taken to have “epistemological” access; since such worlds need not behave consistently, the agents’ knowledge is fallible relative to logical omniscience. The two approaches are known to be equally expressive in propositional systems interpreted over Kripke semantics. In this paper I show that the two approaches are equally expressive in propositional systems interpreted over Montague-Scott (neighborhood) semantics. Furthermore, I provide predicate systems of both awareness and impossible worlds structures interpreted on neighborhood semantics and prove the two systems to be equally expressive.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2008

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References

BIBLIOGRAPHY

Arló-Costa, H. (2002). First order extensions of classical systems of modal logic; the role of the barcan schemas. Studia Logica, 71(1), 87118.CrossRefGoogle Scholar
Arló-Costa, H., & Pacuit, E. (2006). First-order classical model logic. Studia Logica, 84(2), 171210.CrossRefGoogle Scholar
Bicchieri, C. (2006). The Grammar of Society. Cambridge, UK: Cambridge University Press.Google Scholar
Chellas, B. (1980). Modal Logic: An Introduction. Cambridge, UK: Cambridge University Press.CrossRefGoogle Scholar
Cozič, M. (2007). Impossible States at Work: Logical Omniscience and Rational Choice. In Topol, R. et al. , editors. Cognitive Economics: New Trends, Contributions to Economic Analysis, vol. 280, ch. 2, Elsevier Publisher, Amsterdam.Google Scholar
Cresswell, M. J. (1973). Logics and Languages. London, UK: Methuen & Co.Google Scholar
Cubitt, R. P., & Sugden, R. (2003). Common knowledge, salience and convention: a reconstruction of David Lewis’ game theory. Economics and Philosophy, 19, 175210.CrossRefGoogle Scholar
Dekel, E., Lipman, B. L., & Rustichini, A. (1999). Standard state-space models preclude unawareness. Econometrica, 66(1), 159173.CrossRefGoogle Scholar
Fagin, R., & Halpern, J. (1988). Belief, awareness, and limited reasoning. Artificial Intelligence, 34, 3976.CrossRefGoogle Scholar
Fagin, R., Halpern, J., Moses, Y., & Vardi, M. (1995). Reasoning About Knowledge. Cambridge, MA: The MIT Press.Google Scholar
Halpern, J. (2001). Alternative semantics for unawareness. Games and Economic Behavior, 37, 321339.CrossRefGoogle Scholar
Halpern, J., & Rêgo, L. (2006). Reasoning about knowledge of unawareness. In Doherty, P., Mylopulos, J., and Welty, C., editors. Tenth International Conference on Principles of Knowledge Representation and Reasoning. Menlo Park, CA: AAAI Press, pp. 614.Google Scholar
Halpern, J., & Rêgo, L. (2008). Interactive Unawareness Revisited. Games and Economic Behavior 62(1), 232262.CrossRefGoogle Scholar
Halpern, J. Y., & Pucella, R. (2007). Dealing with logical omniscience. In Sarnet, D., editor. Proceedings of Eleventh Conference on Theoretical Aspects of Rationality and Knowledge Presses Universitaire de Louvain. pp. 169176.Google Scholar
Hintikka, J. (1962). Knowledge and Belief. Ithaca, NY: Cornell University Press.Google Scholar
Hintikka, J. (1973a). Logic, Language-Games, and Information. Oxford, UK: Clarendon Press.Google Scholar
Hintikka, J. (1973b). Surface semantics: definition and its motivation. In Leblanc, H. editor. Truth, Syntax, and Modality. Amsterdam: North-Holland. pp. 128147.CrossRefGoogle Scholar
Hintikka, J. (1975). Impossible possible worlds vindicated. Journal of Philosophical Logic, 4, 475484.CrossRefGoogle Scholar
Heifetz, A., Meier, M., & Schipper, B. C. (2006). Interactive unawareness. Journal of Economic Theory, 130, 7894.CrossRefGoogle Scholar
Hughes, G. E., & Cresswell, M. J. (1996). A New Introduction to Modal Logic. New York, NY: Routledge.CrossRefGoogle Scholar
Kripke, S. (1965). A semantical analysis of modal logic II: non-normal propositional calculi. In Henkin, L., & Tarski, A. editors. The Theory of Models. Amsterdam: North-Holland, pp. 206220.Google Scholar
Lewis, D. (1969). Convention: A Philosophical Study. Cambridge, MA: Harvard University Press.Google Scholar
Li, J. (2006). Information structures with unawareness. Manuscript. University of Pennsylvania.Google Scholar
Lipman, B. L. (1999). Decision theory without logical omniscience: toward an axiomatic framework for bounded rationality. The Review of Economic Studies, 66(2), 339361.CrossRefGoogle Scholar
Modica, S., & Rustichini, A. (1999). Unawareness and partitional information structures. Games and Economic Behavior, 27, 265298.CrossRefGoogle Scholar
Parikh, R. (1985). The logic of games. In Ras, Z. W., & Zemankova, M., editors. Annals of Discrete Mathematics. Amsterdam: North-Holland, 24, 111140.Google Scholar
Parikh, R. (1987). Knowledge and the problem of logical omniscience. In Proceedings of the Second International Symposium on Methodologies for intelligent systems, pp. 432439.Google Scholar
Parikh, R. (2002). Social software. Synthese, 132, 187211.CrossRefGoogle Scholar
Pauly, M. (2002). A modal logic for coalitional power in games. Journal of Logic and Computation, 12(1), 149166.CrossRefGoogle Scholar
Rantala, V. (1975). Urn models: a new kind of non-standard model for first-order logic. Journal of Philosophical Logic, 4, 455474.CrossRefGoogle Scholar
Rantala, V. (1982a). Impossible world semantics and logical omniscience. Acta Philosophica Fennica, 35, 106115.Google Scholar
Rantala, V. (1982b). Quantified modal logic: non-normal worlds and propositional attitudes. Studia Logica, 41, 4165.CrossRefGoogle Scholar
Rescher, N., & Brandom, R. (1979). The Logic of Inconsistency. Oxford, UK: Rowman and Littlefield.Google Scholar
Sillari, G. (2005). A logical framework for convention. Synthese, 147(2), 379400.CrossRefGoogle Scholar
Sillari, G. (2006). Models of awareness. In Bonanno, G., van der Hoek, W., & Wooldridge, M., editors. LOFT06: Proceedings. Liverpool, UK: University of Liverpool, pp. 209219.Google Scholar
Sillari, G. (2008a). Common knowledge and convention. Topoi, 27, 2939.CrossRefGoogle Scholar
Sillari, G. (2008a). Models of awareness. In Bonanno, G., van der Hoek, W., & Wooldridge, M. editors. Logic and the Foundations of Game and Decision Theory. Vol. 2: Texts in Logic and Games. Amsterdam: Amsterdam University Press.Google Scholar
Stalnaker, R. (1999). Context and Content. Oxford, UK: MIT Press.CrossRefGoogle Scholar
Thijsse, E. (1993). On total awareness logic. In de Rijke, M. editor. Diamonds and Defaults. Kluwer.Google Scholar
Wansing, H. (1990). A general possible worlds framework for reasoning about knowledge and belief. Studia Logica, 49, 523539.CrossRefGoogle Scholar