Articles

Conjunctions have always been a source of problems for natural language parsers. This paper shows how these problems may be circumvented using a rule.based, walt-and-see parsing strategy. A parser is presented which analyzes conjunction structures deterministically, and the specific rules it uses are described and illustrated. This parser appears to …...

Computer Science Department Boston University 111 Cummington Street Boston, Massachusetts 02215 USA PREL1MIN A R IES We study the formal and linguistic proper- ties of a class of parenthesis-free categorial grammars derived from those of Ades and Steed- man by varying the set of reduction rules. We characterize the reduction …...

67 We examine the relationship between the two grammatical formalisms: Tree Adjoining Grammars and Head Gram- mars. We briefly investigate the weak equivalence of the two formalisms. We then turn to a discussion comparing the linguistic expressiveness of the two formalisms. 1...

Free-word order languages have long posed significant problems for standard parsing algorithms. This paper re- ports on an implemented parser, based on Government- Binding theory (GB) (Chomsky, 1981, 1982), for a par- ticular free-word order language, Warlpiri, an aboriginal language of central Australia. The parser is explicitly de- signed to …...

Taken abstractly, the two-level (Kimmo) morphological framework allows computationally difficult problems to arise. For example, N + 1 small automata are sufficient to encode the Boolean satisfiability problem (SAT) for for- mulas in N variables. However, the suspicion arises that natural-language problems may have a special structure -- not shared …...

An important goal of computational linguistics has been to use linguistic theory to guide the construction of computationally efficient real-world natural language processing systems. At first glance, generalized phrase structure grammar (GPSG) appears to be a blessing on two counts. First, the precise formalisms of GPSG might be a direct …...

This paper describes the SDC PUNDIT, (Prolog UNDerstands Integrated Text), system for processing natural language messages. 1 PUNDIT, written in Prolog, is a highly modular system consisting of dis- tinct syntactic, semantic and pragmatics com- ponents. Each component draws on one or more sets of data, including a lexicon, a …...

Tense, temporal adverbs, and temporal connectives provide information about when events described in English sentences occur. To extract this temporal information from a sentence, it must be parsed into a semantic representation which captures the meaning of tense, temporal adverbs, and temporal connectives. Representations were developed for the basic tenses, …...

s for the tu- torials and panels as well as the texts of the presented papers. Such a meeting can be a success only through the efforts of a large number of people. We are first indebted to the very many authors who submitted papers. While the great majority of …...

We discuss ways of allowing the users of a natural language processor to define, examine, and modify the definitions of any domain-specific words or phrases known to the system. An implementation of this work forms a critical portion of the knowledge acquisition component of our Transportable English-Language Interface (TELl), which …...

Morphological analysis must take into account the spelling-change processes of a language as well as its possi- ble configurations of stems, affixes, and inflectional mark- ings. The computational difficulty of the task can be clari- fied by investigating specific models of morphological pro- cessing. The use of finite-state machinery in …...

This paper presents a technique for interpreting output demands by a natural language sentence generator in a formally transparent and efficient way. These demands are stated in a logical language. A network knowledge base organizes the concepts of the application domain into categories known to the generator. The logical expressions …...

Tree Adjoining Grammar (TAG) is a formalism for natural language grammars. Some of the basic notions of TAG's were introduced in [Joshi,Levy, and Takahashi 19751 and by [Joshi, 1083]. A detailed investigation of the linguistic relevance of TAG's has been carried out in [Kroch and Joshi,1985]. In this paper, we …...

In order to adequately respond to misconceptions involving an object's properties, we must have a context-sensitive method for determining object similarity. Such a method is introduced here. Some of the necessary contextual information is captured by a new notion of object perspective. It is shown how object perspective can be …...

In cooperative man-machine interaction, it is necessary but not sufficient for a system to respond truthfully and informatively to a user's question. In particular, if the system has reason to believe that its planned response might mislead the user, then it must block that conclusion by modifying its response. This …...

In this paper we examine the use of hypotheticals as a heuristic device to assist a case-based reasoner test the strengths, weaknesses, and ramifications of an analysis or argument by exploring and augmenting the space of known cases and indirectly, the attendant spaces of doctrine and argument. Our program, HYPO, …...

This paper describes the SDC PUNDIT, (Prolog UNDerstands Integrated Text), system for processing natural language messages. 1 PUNDIT , written in Prolog, is a highly modular system consisting of distinct syntactic, semantic and prag- matics components. Each component draws on one or more sets of data, includ- ing a lexicon, …...

For natural language understanding systems designed for domains including relatively complex equipment, it is not sufficient to use general knowledge about this equipment. We show problems which can be solved only if the system has access to a detailed equipment model. We discuss features of such models, in particular, their …...

The aim of PROTEUS -- a system for the analysis of short technical texts -- is to increase the reliability of the analysis process through the integration of syntactic and semantic constraints, domain knowledge, and knowledge of discourse structure. This system is initially being applied to the analysis of messages …...

A new method is presented for simplifying the logical expressions used to represent utterance meaning in a natural language system. This simplification method utilizes the encoded knowledge and the limited inference-making capability of a taxonomic knowledge representation system to reduce the constituent structure of logical expressions. The specific application is …...