Paper: The Limits Of Unification

ACL ID P90-1025
Title The Limits Of Unification
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 1990

Current complex-feature based grammars use a sin- gle procedure--unification--for a multitude of pur- poses, among them, enforcing formal agreement between purely syntactic features. This paper presents evidence from several natural languages that unification--variable-matching combined with variable substitution--is the wrong mechanism for effecting agreement. The view of grammar developed here is one in which unification is used for semantic interpre- tation, while purely formal agreement involves only a check for non-distinctness---i.e, variable-matching without variable substitution.