Predictive Combinators: a Method for Efficient Processing of Combinatory Categorial Grammars

A B S T R A C T 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 whextraction 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 combin~tor8 are offered and their effects illustrated. An algorithm for deriving them, as well as s discussion of their semantics, will be presented in forthcoming work.