Gosse bouma

Natural language systems based on Categorial Unification Grammar (CUG) have mainly employed bottomup parsing algorithms for processing. Conventional prediction techniques to improve the efficiency of the • parsing process, appear to fall short when parsing CUG. Nevertheless, prediction seems necessary when parsing grammars with highly ambiguous lexicons or with noncanonical categorial rules. In this paper we present a lexicalist prediction technique for CUG and show thai this may lead to considerable gains in efficiency for both bottom-up and top-down parsing. ...

6p buncha_1 08-05-2013 51 1   Download

From a processing point of view, however, flexible categorial systems are problematic, since they introduce spurious ambiguity. In this paper, we present a flexible categorial grammar which makes extensive use of the product-operator, first introduced by Lambek (1958). The grammar has the property that for every reading of a sentence, a strictly left-branching derivation can be given. This leads to the definition of a subset of the grammar, for which the spurious ambiguity problem does not arise and efficient processing is possible. ...

8p buncha_1 08-05-2013 46 1   Download

We propose a generalization of Categorial Grammar in which lexical categories are defined by means of recursive constraints. In particular, the introduction of relational constraints allows one to capture the effects of (recursive) lexical rules in a computationally attractive manner. We illustrate the linguistic merits of the new approach by showing how it accounts for the syntax of Dutch cross-serial dependencies and the position and scope of adjuncts in such constructions. Delayed evaluation is used to process grammars containing recursive constraints. ...

8p bunmoc_1 20-04-2013 39 1   Download