Abstract
Feature terms are a common denominator of basic data-structures in knowledge representation and computational linguistics. The adaptation of the usual unification algorithms for first order terms is not straightforward, because feature terms may contain logical disjunction. Expansion into disjunctive normal form would reduce the problem more or less to unification of first order terms. But for reasons of efficiency, rewriting into disjunctive normal form should not be compulsory. In this paper, a sequent calculus is defined which gives a clear formal basis for proof optimizations: inference steps which require more than one subproof, i.e. which lead towards a “disjunctive normal form”, are only performed when they are no longer unavoidable. It is shown that the calculus is sound and complete with respect to the so-called feature structure interpretations of feature terms.
This research was done while the author was granted a Monbusho-scholarship at Kyoto University. I wish to thank the researchers in Kyoto, in particular Makoto Nagao and Yuji Matsumoto, for the stimulating research environment they provided. I am in debt to Jochen Dörre and to three anonymous reviewers for pointing out deficiencies of an earlier version of this paper. The responsibility for errors resides with me.
Preview
Unable to display preview. Download preview PDF.
References
Hassan Ait-Kaci. An algebraic semantics approach to the effective resolution of type equations. Theoretical Computer Science, 45:293–351, 1986.
Hassan Ait-Kaci and Roger Nasr. LOGIN: A logic programming language with built-in inheritance. Journal of Logic Programming, 3:185–215, 1986.
R.S. Boyer and J.S. Moore. The sharing of structure in theorem proving programs. Machine Intelligence, 7:101–116, 1972.
Andreas Eisele and Jochen Dörre. Disjunctive unification. Report 124, Institute for Knowledge Based Systems, IBM Germany Science Center, Stuttgart, Baden-Württemberg, 1990.
Melvin Fitting. First-Order Logic and Automated Theorem Proving. Springer, New York, 1990.
Mark Johnson. Attribute-Value Logic and the Theory of Grammar, volume 16 of CSLI Lecture Notes, Center for the Study of Language and Information, Stanford, Ca., 1988.
Robert T. Kasper. Feature Structures: A Logical Theory with Application to Language Analysis, PhD thesis, University of Michigan, Ann Arbor, Michigan, 1987.
Robert T. Kasper and William C. Rounds. The logic of unification in grammar. Linguistics and Philosophy, 13:35–58, 1990.
John T. Maxwell III and Ronald M. Kaplan. An overview of disjunctive constraint satisfaction. In Proceedings of the International Workshop on Parsing Technologies, pages 18–27, Pittsburgh, PA, 1989.
Carl Pollard and Ivan Sag. An Information-Based Syntax and Semantics. I. Fundamentals, volume 13 of Lecture Notes. Center for Study of Language and Information, Stanford, Ca., 1987.
Stuart M. Shieber. An Introduction to Unification-Based Approaches to Grammar. Lecture Notes. Center for the Study of Language and Information, Stanford, Ca., 1986.
Gert Smolka. A feature logic with subsorts. Technical Report 33, IBM Deutschland, Institute for Knowledge-Based Systems, Stuttgart, Baden-Württemberg, 1988. To appear in Journal of Automated Reasoning.
Gert Smolka. Feature constraint logics for unification grammars. Technical Report 93, IBM Deutschland, Institute for Knowledge-Based Systems, Stuttgart, Baden-Württemberg, 1989.
Jürgen Wedekind. Unifikationsgrammatiken und ihre Logik. PhD thesis, Universität Stuttgart, Stuttgart, Baden-Württemberg, 1990. Sonderforschungsbereich 340, Bericht 8-1991.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1993 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
König, E. (1993). An efficient decision algorithm for feature logic. In: Jürgen Ohlbach, H. (eds) GWAI-92: Advances in Artificial Intelligence. Lecture Notes in Computer Science, vol 671. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0019010
Download citation
DOI: https://doi.org/10.1007/BFb0019010
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-56667-0
Online ISBN: 978-3-540-47626-9
eBook Packages: Springer Book Archive