Decidable and undecidable fragments of first-order branching temporal logics

I. Hodkinson1, F. Wolter2, M. Zakharyaschev3
1Department of Computing, Imperial College London, London, UK
2Institut für Informatik, Universität Leipzig, Leipzig, Germany
3Department of Computer Science, King''s College Hospital Medical School, London, UK

Tóm tắt

In this paper we analyze the decision problem for fragments of first-order extensions of branching time temporal logics such as computational tree logics CTL and CTL* or Prior's Ockhamist logic of historical necessity. On the one hand, we show that the one-variable fragments of logics like first-order CTL*-such as the product of propositional CTL* with simple propositional modal logic S5, or even the one-variable bundled first-order temporal logic with sole temporal operator 'some time in the future'-are undecidable. On the other hand, it is proved that by restricting applications of first-order quantifiers to state (i.e., path-independent) formulas, and applications of temporal operators and path quantifiers to formulas with at most one free variable, we can obtain decidable fragments. The positive decidability results can serve as a unifying framework for devising expressive and effective time-dependent knowledge representation formalisms, e.g., temporal description or spatio-temporal logics.

Từ khóa

#Logic #Computer science #Educational institutions #Knowledge representation #Application software #Turning #History

Tài liệu tham khảo

hodkinson, 2001, Monodic fragments of first-order temporal logics: 2000-2001 A.D., LNAI, 2250, 1 10.2178/jsl/1190150040 10.1016/S0168-0072(00)00018-X 10.1016/0022-0000(89)90039-1 hirsch, 2001, Representability is not decidable for finite relation algebras, Trans Amer Math Soc, 353, 1403, 10.1090/S0002-9947-99-02264-3 10.1007/3-540-52513-0_17 10.2307/2274321 gabbay, 2002, Many-Dimensional Modal Logics: Theory and Applications, Studies in Logic, 10.1023/A:1021304426509 gabbay, 2000, Temporal Logic Mathematical Foundations and Computational Aspects, 2 maddux, 1980, The equational theory of C A3 is undecidable, J Symbolic Logic, 45, 311, 10.2307/2273191 10.1016/B978-0-934613-04-0.50016-8 10.1007/3-540-61313-7_89 10.1093/acprof:oso/9780198243113.001.0001 prior, 1968, Nous, 2, 101, 10.2307/2214699 �hrstr�m, 1996, Temporal Logic: From Ancient Ideas to Artificial Intelligence, Studies in Logic and Philosophy, 57 10.2307/1995086 10.1023/A:1004359325754 wooldridge, 1992, A first-order branching time logic of multi-agent systems, Proceedings of the 11th European Conference on Artificial Intelligence, 234 10.2307/2695115 10.1090/memo/0066 10.1109/TIME.2002.1027466 10.1145/4904.4999 10.1023/A:1004275029985 10.1016/S0168-0072(01)00124-5 chagrov, 1997, Modal Logic 10.2307/2273296 10.2307/2275595 10.1111/j.1755-2567.1978.tb00175.x wolter, 2002, Qualitative spatio-temporal representation and reasoning: A computational perspective, Exploring Artificial Intelligence in the New Millenium 10.1007/978-3-642-59207-2 10.1016/B978-0-444-88074-1.50021-4 clarke, 1981, Synthesis of synchronization skeletons for branching time temporal logic, Proc IBM Workshop Logics of Programs, 52