Paper: F-PATR: Functional Constraints For Unification-Based Grammars

ACL ID P93-1029
Title F-PATR: Functional Constraints For Unification-Based Grammars
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 1993

Motivation for including relational constraints other than equality within grammatical formalisms has come from discontinuous constituency and partially free word order for natural languages as well as from the need to define combinatory operations at the most basic level for languages with a two-dimensional syntax (e.g. , mathematical notation, chemical equations, and various diagramming languages). This paper presents F-PATR, a generalization of the PATR-II unification-based for- malism, which incorporates relational constraints expressed as user-defined functions. An operational semantics is given for unification that is an adaptation and extension of the approach taken by Ait-Kaci and Nasr (1989). It is designed particularly for unification- based formalisms implemented in functional p...