Classification in Feature-based Default Inheritance Hierarchies

Abstract : When one works with a system that utilizes inheritance hierarchies the following problem often arises. A new object is introduced and it must be integrated into a hierarchy; under which classes in the hierarchy should the new object be positioned? In this paper, I formalize this problem for feature-based default inheritance hierarchies. Since it turns out to be NP-complete, I present an approximation algorithm for it. I show that this algorithms is efficient and look at some of the possible problematic situations for the algorithm. Although more analysis and experimentation are needed, these preliminary results show that the algorithm warrants such efforts.

[1]  Norman M. Fraser,et al.  Making DATR Work for Speech: Lexicon Compilation in SUNDIAL , 1992, Comput. Linguistics.

[2]  Geoffrey K. Pullum,et al.  Generalized Phrase Structure Grammar , 1985 .

[3]  D. Flickinger.  Lexical rules in the hierarchical lexicon , 1989 .

[4]  John A. Carroll,et al.  A Practical Approach to Multiple Default Inheritance for Unification-Based Lexicons , 1992, CL.

[5]  Dan Flickinger,et al.  Inheritance and Complementation: a Case Study of Easy Adjectives and Related Nouns , 1992, CL.

[6]  Bob Carpenter,et al.  The logic of typed feature structures , 1992 .

[7]  Noam Chomsky,et al.  The Sound Pattern of English , 1968 .

[8]  Noam Chomsky,et al.  वाक्यविन्यास का सैद्धान्तिक पक्ष = Aspects of the theory of syntax , 1965 .

[9]  Hans-Ulrich Krieger,et al.  Feature-based inheritance networks for computational lexicons , 1994 .

[10]  Ivan A. Sag,et al.  Information-based syntax and semantics , 1987 .

[11]  Geoffrey K. Pullum,et al.  Category Structures , 1988, Comput. Linguistics.

[12]  Lynne J. Cahill.  Morphonology in the Lexicon , 1993, EACL.

[13]  Alberto Martelli,et al.  An Efficient Unification Algorithm , 1982, TOPL.

[14]  Sabine Reinhard,et al.  Verarbeitungsprobleme nichtlinearer Morphologien Umlautbeschreibung in einem hierarchischen Lexikon , 1990, GLDV-Jahrestagung.

[15]  Ted Briscoe,et al.  Inheritance, Defaults and the Lexicon: Inheritance, Defaults and the Lexicon , 1994 .

[16]  David S. Johnson,et al.  Approximation algorithms for combinatorial problems , 1973, STOC.

[17]  Marc Light,et al.  INSYST: An Automatic Inserter System for Hierarchical Lexica , 1993, EACL.

[18]  David S. Touretzky,et al.  The Mathematics of Inheritance Systems , 1984 .

[19]  László Lovász,et al.  On the ratio of optimal integral and fractional covers , 1975, Discret. Math..

[20]  Ivan A. Sag,et al.  Information-Based Syntax and Semantics: Volume 1, Fundamentals , 1987 .