tailieunhanh - Báo cáo khoa học: "COMPARATIVES AND ELLIPSIS "

This paper analyses the syntax and semantics of English comparatives, and some types of ellipsis. It improves on other recent analyses in the computational linguistics literature in three respects: (i) it uses no tree- or logical-form rewriting devices in building meaning representations (ii) this results in a fully reversible linguistic description, equally suited for analysis or generation (iii) the analysis extends to types of elliptical comparative not elsewhere treated. INTRODUCTION Many treatments of the English comparative construction have been advanced recently in the computational linguistics literature (. Rayner and Banks, 1989; Ballard, 1988). . | COMPARATIVES AND ELLIPSIS s. G. Pulman SRI International and University of Cambridge Computer Laboratory SRI International Cambridge Computer Science Research Centre 23 Miller s Yard Cambridge CB2 IRQ sgp@ .com ABSTRACT This paper analyses the syntax and semantics of English comparatives and some types of ellipsis. It improves on other recent analyses in the computational linguistics literature in three respects i it uses no tree- or logical-form rewriting devices in building meaning representations ii this results in a fully reversible linguistic description equally suited for analysis or generation iii the analysis extends to types of elliptical comparative not elsewhere treated. INTRODUCTION Many treatments of the English comparative construction have been advanced recently in the computational linguistics literature . Rayner and Banks 1989 Ballard 1988 . This interest reflects the importance of the construction for many natural language applications especially those concerning access to databases where it is natural to require information about quantitative differences and limits which are most naturally expressed in terms of comparatives and superlatives. However all of these analyses have their defects as no doubt does this one . The most pervasive of these defects is one of principle they all place a high reliance on non-compositional methods tree or formula rewriting for assembling the logical forms of comparatives even in cases that might be thought to be straightforwardly compositional. These devices mean that the grammatical descriptions involved lack to varying extents the important property of reversibility they can only be used to analyse not to generate expressions of comparison. This is a serious restriction on the practical usefulness of such analyses. The analysis presented here of the syntax and compositional semantics of the main instances of the English comparative and superlative is intended to provide a fairly theory-neutral off the