tailieunhanh - Báo cáo khoa học: "PREDICTIVE COMBINATORS A METHOD PROCESSING OF COMBINATORY CATEGORIAL GRAMMARS"

Steedman (1985, 1987) and others have proposed that Categorial Grammar, a theory of syntax in which grammatical categories are viewed as functions, be augmented with operators such as functional composition and type raising in order to analyze • noncanonical" syntactic constructions such as wh- extraction and node raising. A consequence of these augmentations is an explosion of semantically equivalent derivations admitted by the grammar. The present work proposes a method for circumventing this spurious ambiguity problem. It involves deriving new, specialized combinators and replacing the orginal basic combinators with these derived ones. In this paper, examples of these predictive. | PREDICTIVE COMBINATORSs A METHOD FOR EFFICIENT PROCESSING OF COMBINATORY CATEGORIAL GRAMMARS Kent Wittenburg MCC Human Interface Program 3500 West Balcones Center Drive Austin TX 78759 Department of Linguistics University of Texas at Austin Austin TX 78712 ABSTRACT Steedman 1985 1987 and others have proposed that Categorial Grammar a theory of syntax in which grammatical categories are viewed as functions be augmented with operators such as functional composition and type raising in order to analyze noncanonical syntactic constructions such as wh- extraction and node raising. A consequence of these augmentations is an explosion of semantically equivalent derivations admitted by the grammar. The present work proposes a method for circumventing this spurious ambiguity problem. It involves deriving new specialized combinators and replacing the orginal basic combinators with these derived ones. In this paper examples of these predictive combinators are offered and their effects illustrated. An algorithm for deriving them as well as a discussion of their semantics will be presented in forthcoming work. Introduction In recent years there has been a resurgence of interest in Categorial Grammar Adjukeiwicz 1935 Bar-Hillel 1953 . The work of Steedman 1985 1987 and Dowty 1987 is representative of one recent direction in which Categorial Grammar CG has been taken in which the operations of functional composition and type raising have figured in analyses of noncanonical structures such as wh- dependencies and nonconstituent conjunction. Based on the fact that such operations have their roots in the combinatory calculue Curry and Feys 1958 this line of Categorial Grammar has come to be known as Combinatory Categorial Grammar CCG . While such an approach to syntax has been demonstrated to be suitable for computer implementation with unification-based grammar formalisms Wittenburg 1986a doubts have arisen over the efficiency with which such grammars can be processed. Karttunen .