this paper is an attempt to resolve these problems in a satisfactory manner. Although we believe that this algorithm could be seen as an instance of a uniform architecture for parsing and generation--just as the extended Earley parser (Shieber, 1985b) and the bottom-up generator were instances of the generalized Earley deduction architecture---our efforts to date have been aimed foremost toward the development of the algorithm for generation alone. We will mention efforts toward this end in Section 5

We describe minimal recursion semantics (MRS), a framework for semantics within HPSG, which considerably simplies transfer and generation. We discuss why, in general, a semantic representation with minimal structure is desirable for transfer and illustrate how a descriptively adequate representation with a non-recursive structure may be achieved. The paper illustrates the application of MRS to transfer with a series of examples and compares the approach to others which have been previously adopted within unication based frameworks. Our account involves the use of both language-specic and interlingual predicates or relations and we illustrate how this may be exploited to allow MRS to be used to investigate dierent lexical semantic approaches. 1 Semantic representation and transfer In this paper we describe a semantic representation for HPSG known as minimal recursion semantics (MRS), which is being utilized in the English grammar being developed for the Verbmobil project. Verbmobil...

We describe a generator for rule-based grammars which are primarily lexicalist but may introduce some semantics via constructions. By combining chart generation with a treatment of modification by adjunction, we obtain substantial performance improvements over standard lexically-driven chart-generation.

It has long been noted that Natural Language utterances can communicate more than their conventional meaning (Grice, 1975). It has also been noted that behaving appropriately in response to instructions given in Natural Language requires understanding more than their conventional meaning (Suppes and Crangle, 1988; Webber and Di Eugenio, 1990; Webber et al., 1992). This paper addresses one mechanism by which speakers convey, and hearers derive, such additional aspects of meaning -- a mechanism we call pragmatic overloading. In pragmatic overloading, a clause interpreted as conveying directly or indirectly the goal fi of an action ff which is described by some other clause, forms the basis of constrained inference that leads to additional information about the action ff. The paper demonstrates pragmatic overloading through a variety of clausal adjuncts. We then discuss a framework that supports many of the inferences that pragmatic overloading gives rise to. This framework integrates a ...

This report is a full description of the lexical knowledge base system (LKB) and the representation language (LRL) developed on the Esprit ACQUILEX project. The LKB system is designed to allow the representation of multilingual lexical information in a way which integrates lexical semantics with syntax and formal semantics. The LRL is a typed feature structure language which makes it possible to represent the lexicon as a highly structured object and to capture relationships between individual word senses by (default) inheritance and by lexical rules. The extension to multilingual representation allows a concise and natural description of translation mismatches. Most of this report consists of a detailed formal description of the LRL --- this is augmented with appendices containing the user manual, an implementation outline and a discussion of some of the algorithms used, and a bibliography of papers which describe the LKB and its use within ACQUILEX. (Some of this material has been pu...

I show how a conversational process that takes simple, intuitively meaningful steps may be understood as a sophisticated computation that derives the richly detailed, complex representations implicit in our knowledge of language. To develop the account, I argue that natural language is structured in a way that lets us formalize grammatical knowledge precisely in terms of rich primitives of interpretation. Primitives of interpretation can be correctly viewed intentionally, as explanations of our choices of linguistic actions; the model therefore fits our intuitions about meaning in conversation. Nevertheless, interpretations for complex utterances can be built from these primitives by simple operations of grammatical derivation. In bridging analyses of meaning at semantic and symbol-processing levels, this account underscores the fundamental place for computation in the cognitive science of language use.

In the following the components of a workbench for the grammar formalism of Schema-Tree Adjoining Grammars (S-TAGs) are outlined. This workbench can also serve as a workbench for pure TAGs because it provides a component which transforms an arbitrary TAG into an S-TAG in a non-trivial manner. Another interesting property of the workbench is that it provides a parser, which is realized as a reversible component to generate as well.

This document is intended as a description of the current mechanisms in the ACQUILEX LKB for constraint resolution and for the application of tlinks. It does not contain any detailed account of particular translation mismatches etc --- these will be provided (at some point) in Copestake and Sanfilippo (in preparation). This document incorporates some information from previously published sources, on tlinks in particular, in order to provide a single consistent description (see, in particular, Copestake and Sanfilippo, 1993). Eventually this document will form part of the full description of the LKB. 2 Types and constraints

This paper is a detailed discussion of semantic transfer in the context of the Verbmobil Machine Translation project. The use of semantic transfer as a translation mechanism is introduced and justified by comparison with alternative approaches. Some criteria for evaluation of transfer frameworks are discussed and a comparison is made of three different approaches to the representation of translation rules or equivalences. This is followed by a discussion of control of application of transfer rules and interaction with a domain description and inference component.

Objects Finally, no discussion of linguistic description could be complete without a discussion of the range of further abstract objects that grammar implicates, such as STATES, POSSIBILITIES, FACTS and PROPOSITIONS. But there is perhaps one notable difference between these abstractions and the individuals we have already considered. A specification or system may be equipped with an inventory of concrete individuals to describe, by listing the objects or places in its environment, the meaningfully different quantities it can reason about, and even the events in some history or plan. But to describe abstract individuals in interesting ways, a system needs a generative understanding of them, and needs to create representations of them by inference, on the fly. Such inference in turn requires a more sophisticated implementation. At the same time, the linguistic expressions that describe abstractions are more rarefied. This gives two reasons why knowledge representation does not approach abstractions with the same urgency as other individuals. Of course, abstract individuals remain quite intriguing, as we shall now discover.