Conceptual Structures and CCG: Linking Theory and Incorporated Argument Adjuncts

CONCEPTUAL STRUCTURES AND CCG: LINKING THEORY AND INCORPORATED ARGUMENT ADJUNCTS Michael White Department of Computer and Information Science University of Pennsylvania Philadelphia, PA, USA mwhit e~linc, cis. npenn, edu Abstract In Combinatory Categnrial Grammar (CCG) [Ste90, Ste91], semantic function-argument structures are com- positionally produced through the course of a deriva- tion. These structures identify, inter alia, which enti- ties play the same roles in different events for expres- sions involving a wide range of coordinate constructs. This sameness of role (i.e. ~hematie) information is not identified, however, across eases of verbal diathe- sis. To handle these cases as well, the present paper demonstrates how to adapt the solution developed in Conceptual Semantics [Jac90, Jac91] to fit the CCG paradigm. The essence of the approach is to redefine the Link- ing Theory component of Conceptual Semantics in terms of CCG categories, so that derivations yield con- ceptual structures representing the desired thematic in- formation; in this way no changes are required on the CCG side. While this redefinition is largely straightfor- ward, an interesting problem arises in the case of Corn ceptual Semantics' Incorporated Argument Adjuncts. In examining these, the paper shows that they cannot be treated as adjuncts in the CCG sense without intro- ducing new machinery, nor without compromising the independence of the two theories. For this reason, the paper instead adopts the more traditional approach of treating them as oblique arguments. 1 Introduction Tile present paper represents the first attempt to integrate Mark Steedman's theory of Combinatorial Categorial Grammar (CCG) [Ste90, Ste91] with Ray Jackendoff's theory of Conceptual Semantics [Jac90, ~lac91]. The former is known for its successhd treat- ment of tong-distance dependencies, coordination, and, more recently, matters of discourse focus relating to intonation---none of which have been treated within Conceptual Semantics. The latter is known for its de- velopment of conceptual structures, which are mental representations intended to serve as the link between language and other areas of cognition, e.g. vision, ac- tion and inference--which CCG stops short of. Since CCG is a. lexically oriented theory of grammar, the two are entirely compatible, as well as complementary. The immediate motivation to attempt such an inte- gration, and the focus of the present paper, is CCG's in- complete treatment of sameness of role (i.e. thematic) information. In CCG, semantic function-argument structures are compositionally produced through the course of a derivation. These structures identify, in- ter alia, which entities play the same roles in different events for expressions involving a wide range of coor- dinate constructs. For example, the semantic function- argument structure shown in (lb) is derived for the sentence in (la) via type-raising, composition, and co- ordination of the bracketed non-standard constituent, following the analysis of Dowty [Dow88]: 1 (la) Jack filled [the urn with coffee] and [the thermos with milk]. (lb) (fill' urn' coffee' jack') & (fill' thermos' mill" jack') Of course, such semantic function-argument structures are intended only for illustrative purposes; indeed, ac- cording to Steedman, semantic constants like urn' are "mere placeholders for a …

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