Paper: DATR Theories And DATR Models

ACL ID P95-1008
Title DATR Theories And DATR Models
Venue Annual Meeting of the Association of Computational Linguistics
Session Main Conference
Year 1995

Evans and Gazdar (Evans and Gazdar, 1989a; Evans and Gazdar, 1989b) intro- duced DATR as a simple, non-monotonic language for representing natural language lexicons. Although a number of implemen- tations of DATR exist, the full language has until now lacked an explicit, declarative se- mantics. This paper rectifies the situation by providing a mathematical semantics for DATR. We present a view of DATR as a lan- guage for defining certain kinds of partial functions by cases. The formal model pro- vides a transparent treatment of DATR's notion of global context. It is shown that DA-I'R's default mechanism can be accoun- ted for by interpreting value descriptors as families of values indexed by paths.