Abstract
This paper offers a brief analysis of the unification problem in modal transitive logics related to the logic S4: S4 itself, K4, Grz and Gödel-Löb provability logic GL. As a result, new, but not the first, algorithms for the construction of ‘best’ unifiers in these logics are being proposed. The proposed algorithms are based on our earlier approach to solve in an algorithmic way the admissibility problem of inference rules for S4 and Grz. The first algorithms for the construction of ‘best’ unifiers in the above mentioned logics have been given by S. Ghilardi in [16]. Both the algorithms in [16] and ours are not much computationally efficient. They have, however, an obvious significant theoretical value a portion of which seems to be the fact that they stem from two different methodological approaches.
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Baader F., Siekmann J.H.: ‘Unification theory’. In: Gabbay, D.M., Hogger, C.J., Robinson, J.A. (eds) Handbook of Logic in Artificial Intelligence and Logic Programming., pp. 41–125. Oxford University Press, Oxford (1994)
Baader, F., and T. Nipkow, Term Rewriting and All That. Cambridge University Press, 1998.
Baader, F., and R. Küsters, Unification in a Description Logic with Transitive Closure of Roles. LPAR 2001, pp. 217–232.
Baader F., Narendran P.: ‘Unification of Concept Terms in Description Logics’. J. Symb. Comput. 31(3), 277–305 (2001)
Baader, F., and W. Snyder, ‘Unification Theory’. In J. A. Robinson and A. Voronkov (eds.), Handbook of Automated Reasoning, volume I. Elsevier Science Publishers, 2001, pp. 447–533.
Baader, F., D. Calvanese, D. McGuinness, D. Nardi, and P. F. Patel-Schneider (eds.), The Description Logic Handbook: Theory, Implementation, and Applications. Cambridge University Press, 2003.
Baader F., Morawska B.: ‘Unification in the Description Logic EL’. Logical Methods in Computer Science 6(3), 1–31 (2010)
Baader, F., and S. Ghilardy, ‘Unification in modal and description logics’. Logic J. of IGPL 2010, doi:10.1093/jigpal/jzq008, First published online: April 29, 2010.
Babenyshev, S., and V. Rybakov, ‘Linear Temporal Logic LTL: Basis for Admissible Rules’, J. Logic Computation 2010, doi:10.1093/logcom/exq020,21.
Babenyshev, S., and V. Rybakov, ‘Unification in Linear Temporal Logic LTL’, 2010, submitted.
Babenyshev, S., V. Vladimir, R. Schmidt, and D. Tishkovsky. ‘A tableau method for checking rule admissibility in S4’. In Proc. of the 6th Workshop on Methods for Modalities (M4M-6), Copenhagen, 2009.
Blackburn, P., J. van Benthem, and F. Wolter (eds.), The Handbook of Modal Logic. Elsevier, 2006.
Gabbay D., Reyle U.: ‘N-Prolog: - An extension of Prolog with hypothetical implications’. Journal of Logic Programming 1, 391–355 (1984)
Ghilardi S.: ‘Unification Through Projectivity’. J. Log. Comput. 7(6), 733–752 (1997)
Ghilardi S.: ‘Unificationinintuitionisticlogic’. J.Symb. Log. 64(2), 859–880 (1999)
Ghilardi S.: ‘Best solving modal equations’. Ann. Pure Appl. Logic 102(3), 183–198 (2000)
Ghilardi S.: ‘Unification, finite duality and projectivity in varieties of Heyting algebras’. Ann. Pure Appl. Logic 127(1–3), 99–115 (2004)
Iemhoff R.: ‘On the admissible rules of intuitionistic propositional logic’. J. Symb. Log. 66(1), 281–294 (2001)
Iemhoff R.: ‘On The Admissible Rules of Intuitionistic Propositional Logic’. J. Symb. Log. 66(1), 281–294 (2001)
Iemhoff, R., Towards a Proof System for Admissibility. CSL 2003, pp. 255–270.
Iemhoff R., Metcalfe G.: ‘Proof theory for admissible rules’. Ann. Pure Appl. Logic 159(1–2), 171–186 (2009)
Jerabek E.: ‘Admissible rules of modal logics’. Journal of Logic and Computation 15(4), 411–431 (2005)
Jerabek E.: ‘Independent bases of admissible rules’. Logic Journal of the IGPL 16(3), 249–267 (2008)
Jerabek E.: ‘Admissible rules of Lukasiewicz logic’. Journal of Logic and Computation 20(2), 425–447 (2010)
Knuth D. E., Bendix P. B.: ‘Simple word problems in universal algebras’. In: Leech, J. (ed) Computational Problems in Abstract Algebra., Pergamon Press, Oxford (1970)
Kröger, F., and S. Merz, Temporal Logic and State Systems, Texts in Theoretical Computer Science. An EATCS Series, Springer, Berlin Heidelberg, 2008.
Levy, J., and M. Villaret, Nominal Unification from a Higher-Order Perspective. RTA 2008, pp. 246–260.
Oliart A., Snyder W.: ‘Fast algorithms for uniform semi-unification’. J. Symb. Comput. 37(4), 455–484 (2004)
Robinson J. A.: ‘A machine oriented logic based on the resolution principle. J. of the ACM 12(1), 23–41 (1965)
Rybakov V.V.: ‘A criterion for admissibility of rules in the modal system S4 and the intuitionistic logic’. Algebra and Logica 23(5), 369–384 (1984)
Rybakov V.V.: ‘Problems of Substitution and Admissibility in the Modal System Grz and in Intuitionistic Propositional Calculus’. Ann. Pure Appl. Logic 50(1), 71–106 (1990)
Rybakov V.V.: ‘Rules of Inference with Parameters for Intuitionistic Logic’. J. Symb. Log. 57(3), 912–923 (1992)
Rybakov V.V.: ‘Logical equations and admissible rules of inference with parameters in modal provability logics’. Studia Logica 49(2), 215–239 (1990)
Rybakov, V.V., Admissible Logical Inference Rules. Series: Studies in Logic and the Foundations of Mathematics, Vol. 136, Elsevier Sci. Publ., North-Holland, 1997.
Rybakov V.V.: ‘Logics with the universal modality and admissible consecutions’. Journal of Applied Non-Classical Logics 17(3), 383–396 (2007)
Rybakov V.V.: ‘Linear temporal logic with until and next, logical consecutions’. Ann. Pure Appl. Logic 155(1), 32–45 (2008)
Rybakov V.V.: ‘Multi-modal and Temporal Logics with Universal Formula – Reduction of Admissibility to Validity and Unification’. J. Log. Comput. 18(4), 509–519 (2008)
Wójcicki R.: ‘Theories, Theoretical Models, Truth, part I; Popperian and non- Popperian Theories in science’. Foundations of Science 1, 337–406 (1995/96)
Wójcicki R.: ‘Theories, Theoretical Models, Truth, part II: Tarski’s theory of truth and its relevance for the theory of science’. Foundations of Science 4, 471–516 (1995/96)
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Dedicated to the outstanding logician Ryszard Wójcicki on the occasion of his 80th birthday
Special issue in honor of Ryszard Wójcicki on the occasion of his 80th birthday
Edited by J. Czelakowski, W. Dziobiak, and J. Malinowski
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Rybakov, V.V. Best Unifiers in Transitive Modal Logics. Stud Logica 99, 321 (2011). https://doi.org/10.1007/s11225-011-9354-y
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DOI: https://doi.org/10.1007/s11225-011-9354-y