tailieunhanh - Báo cáo khoa học: "Semantic construction in Feature-Based TAG"

In that framework, the basic units are (elementary) We propose a semantic construction metrees and two operations are used to combine trees thod for Feature-Based Tree Adjoining into bigger trees, namely, adjunction and substiGrammar which is based on the derived tution. Because the adjunction rule differs from tree, compare it with related proposals standard phrase structure rules, two structures are and briefly discuss some implementation associated with any given derivation: a derivation possibilities. . | Semantic construction in Feature-Based TAG Claire Gardent CNRS Nancy BP 239 - Campus Scientifique 54506 Vandoeuvre-les-Nancy France gardent@ Laura Kallmeyer TALaNa Lattice Université Paris 7 2 place Jussieu 75251 Paris Cedex 05 France Abstract We propose a semantic construction method for Feature-Based Tree Adjoining Grammar which is based on the derived tree compare it with related proposals and briefly discuss some implementation possibilities. 1 Introduction Semantic construction is the process of constructing semantic representations for natural language expressions. Perhaps the most well-known proposal for semantic construction is that presented in Montague 1974 in which grammar rules are applied in tandem with semantic rules to construct not only a syntactic tree but also a lambda term representing the meaning of the described constituent. Montague s approach gave rise to much further work aiming at determining the correct rules and representations needed to build a representation of natural language meaning. In particular computational grammars were developed which by and large took on Montague s proposal building semantic representations in tandem with syntactic structures. Thus for instance Copestake et al. 2001 shows how to specify a Head Driven Phrase Structure Grammar HPSG which supports the parallel construction of a phrase structure or derived tree and of a semantic representation Zeevat et al. 1987 shows it for Unification Categorial Grammar UCG and Dalrymple 1999 for Lexical Functional grammar LFG . One grammatical framework for which the idea of a Montague style approach to semantic construction has not been fully explored is Tree Adjoining Grammar TAG Joshi and Schabes 1997 . In that framework the basic units are elementary trees and two operations are used to combine trees into bigger trees namely adjunction and substitution. Because the adjunction rule differs from standard phrase structure rules two .