A unification-based approach to multiple VP Ellipsis resolution

A unification-based approach to multiple VP Ellipsis resolution* Claire Gardent GRIL, Universitd de Clermont-Ferrand (France) and Department of Computational Linguistics, Universiteit van Amsterdam Spuistraat 134, 1012 VB Amsterdam (The Netherlands) E-marl: claire@mars.let.uva.nl Abstract An assumption shared by many theories of discourse is that discourse structure con- strains anaphora resolution (cf. [Grosz and Sidner 1986] for definite NPs, [Lascarides and Asher 1991], [Nakhimovsky 1988] for temporal anaphora, [Webber 1990] for deictic pronouns and [Gardent 1991], [Prfist and Scha 1990] for VP ellipsis). The aim of this paper is (i) to show that this as- sumption also applies to multiple VP ellip- sis (VPE), (ii) to argue that other levels of linguistic information (such as syntax and semantics) interact with discourse structure in determining multiple VPE acceptability and (iii)to make these intuitions precise by providing a unification-based account of multiple VPE resolution. 1 Introduction [Klein and Stainton-Ellis 1989] convincingly argue that VPE need not resolve to the nearest possible antecedent. The most intricate examples they give to support this claim involve what they dubbed mul- tiple VPE and can be illustrated by the follow- ing discourses (square brackets surround antecedent VPs, 01 indicates VP ellipses and indices represent anaphoric dependencies) 1 : *The work reported here was partially carried out in the LRE Project 61-062, Towards a declarative theory of discourse. 1 Although this data often raises suspicion among lin- guistic audiences as to its credibility, the facts are that (1) it is real life data and (2) it can be understood and it is usually understood in an unambiguous fashion. Hence (1) I promised myself I [x wouldn't go to Manch- ester] unless I first [2 opened a big stack of mail]. I didn't 02, so I didn't 01. (Nesting) (2) If you [1 work hard, make the right choices and keep your nose clean], you [2 get ahead]. If you don't 01, you don't 09.. (Crossing) (3) I was [1 really thin] then, and I tried some ski- pants that [2 looked really good on me], and I [3 should have bought them]. But I didn't 03, and now I 'm not 01 and they wouldn't 0~. (Mi~ed) As these examples show, there is not one pattern relating multiple VPEs to their antecedents, but at least three: nesting, crossing and mixed. Nesting and crossing can be represented as follows (where VPi and 0i represent antecedent and elliptical VPs respectively): Nesting: VP1 ... VP,~ 0n ... 01 Crossing: VP1... VPn 01...0n while a mixed pattern simply is a configuration in which both crossing and nesting occur. According to this terminology, (1) illustrates a nesting pattern, (2) shows a crossing pattern and (3) a mixed pattern. Thus, it is clear that no unique dependency config- uration constrains the resolution of multiple VPEs. On the contrary, it appears that all patterns are pos- sible and thus that any configurational restriction on VPE resolution is doomed to failure. Interestingly however, despite the multiple ways in which each of the VPEs could be resolved, there …

Content truncated to 500 words