Building a LCS-Based Lexicon in TAGs

Representation and Acquisition of Lexical Knowledge: Polysemy, Ambiguity, and Generativity

Volume

Representation and Acquisition of Lexical Knowledge: Polysemy, Ambiguity, and Generativity

Contents

We are interested in building a lexicon for interlingual machine translation (MT) and in examining the formal properties of an interlingua as a language in its own right. As such it should be possible to define a lexicalized grammar for the representation of lexical entries and a set of operations over that grammar that can be used to both analyze and generate interlingua representations. The interlingua we discuss in this paper is Le.,dcal Conceptual Structure (LCS) as formulated by Dorr (1993) based on work by Jackendoff (1983, 1990). This is described in the next section, and is followed by the presentation of a grammar for LCS as a representation language. The grammar formalism whose operations we examine with respect to their ability to compose LCS representations is Feature-Based Lexicalized Adjoining Grammar, (FB-LTAG), a version of Tree Adjoining Grammar (TAG) (Joshi et al (1975), Schabes (1990), Vijay-Shanker (1987)), and its description, along with example TAG structures, forms our final section. What we find is that the implementation of LCS as a TAG, although not completely straightforward, can be done, providing the full power of the well-defined mathematical properties of TAGs as a basis for describing the formal properties of LCS.