Journal of Logic, Language and Information

, Volume 8, Issue 1, pp 1–16

Off-Line Parsability and the Well-Foundedness of Subsumption

Authors

  • Shuly Wintner
    • Department of Computer Science
    • Institute of Technology
  • Nissim Francez
    • Department of Computer Science
Article

DOI: 10.1023/A:1008252619710

Cite this article as:
Wintner, S. & Francez, N. Journal of Logic, Language and Information (1999) 8: 1. doi:10.1023/A:1008252619710

Abstract

Typed feature structures are used extensively for the specification of linguistic information in many formalisms. The subsumption relation orders TFSs by their information content. We prove that subsumption of acyclic TFSs is well founded, whereas in the presence of cycles general TFS subsumption is not well founded. We show an application of this result for parsing, where the well-foundedness of subsumption is used to guarantee termination for grammars that are off-line parsable. We define a new version of off-line parsability that is less strict than the existing one; thus termination is guaranteed for parsing with a larger set of grammars.

computational linguistics parsing feature structures unification

Copyright information

© Kluwer Academic Publishers 1999