410 research outputs found

    A unification-based natural language interface to a database.

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    An implementation of a Lexical Functional Grammar (LFG) natural language front-end to a database is presented, and its capabilities demonstrated by reference to a set of queries used in the Chat-80 system. The potential of LFG for such applications is explored. Other grammars previously used for this purpose are briefly reviewed and contrasted with LFG. The basic LFG formalism is fully described, both as to its syntax and semantics, and the deficiencies of the latter for database access application shown. Other current LFG implementations are reviewed and contrasted with the LFG implementation developed here specifically for database access. The implementation described here allows a natural language interface to a specific Prolog database to be produced from a set of grammar rule and lexical specifications in an LFG-like notation. In addition to this the interface system uses a simple database description to compile metadata about the database for later use in planning the execution of queries. Extensions to LFG's semantic component are shown to be necessary to produce a satisfactory functional analysis and semantic output for querying a database. A diverse set of natural language constructs are analysed using LFG and the derivation of Prolog queries from the F-structure output of LFG is illustrated. The functional description produced from LFG is proposed as sufficient for resolving many problems of quantification and attachment

    Experiences with the GTU grammar development environment

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    In this paper we describe our experiences with a tool for the development and testing of natural language grammars called GTU (German: Grammatik-Testumgebumg; grammar test environment). GTU supports four grammar formalisms under a window-oriented user interface. Additionally, it contains a set of German test sentences covering various syntactic phenomena as well as three types of German lexicons that can be attached to a grammar via an integrated lexicon interface. What follows is a description of the experiences we gained when we used GTU as a tutoring tool for students and as an experimental tool for CL researchers. From these we will derive the features necessary for a future grammar workbench.Comment: 7 pages, uses aclap.st

    From treebank resources to LFG F-structures

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    We present two methods for automatically annotating treebank resources with functional structures. Both methods define systematic patterns of correspondence between partial PS configurations and functional structures. These are applied to PS rules extracted from treebanks, or directly to constraint set encodings of treebank PS trees

    GTU - A workbench for the development of natural language grammars

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    In this report we present a Prolog tool for the development and testing of natural language grammars called GTU (German: Grammatik-Testumgebung; grammar test environment). GTU offers a window-oriented user interface that allows the development and testing of natural language grammars under three formalisms. In particular it contains a collection of German test sentences and two types of German lexicons. Both of the lexicons can be adapted to a given grammar via an integrated lexicon interface. GTU has been implemented in Prolog both under DOS and UNIX. It was originally developed as a tutoring tool to support university courses on syntax analysis but in its UNIX-version it allows for the development of large grammars

    Egy ''reális'' interpretációs rendszer és számítógépes implementációja = A ''real'' interpretation system and its computational implementation

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    A ReALIS Elméleti és Számítógépes Nyelvészeti Kutatócsoport olyan interpretációs rendszert dolgozott ki, amely elsődlegesen a formális diskurzus-szemantika reprezentacionalista (DRT, SDRT) ágának örököse, ugyanakkor kielégíti az antireprezentacionalista irányzat alapkövetelményét az „extra reprezentációs szint” kiküszöbölésére vonatkozóan. Mi ennek az ára? Az, hogy a diskurzusreprezentáció egyfajta elmereprezentáció részévé válik, így ágyazódik be a referenciális szemantikák elengedhetetlen komponensét jelentő világmodellbe. Ez azonban nem ár, hanem inkább lehetőség az antipszichologista formális szemantika és az informális kognitív nyelvészet integrálására. A számítógépes nyelvészet intelligens szövegfeldolgozásra törekvő ágában pedig új lehetőséget kínál például a gépi fordítás olyan megközelítésére, ami a humán fordító elméjének szimulálására épül. | Our ReALIS Theoretical and Computational Linguistics Team has worked out an interpretation system which is primarily the descendant of the representationalist branch of formal discourse semantics (DRT, SDRT) but, at the same time, satisfies the principal requirement of the anti-representationalist branch pertaining to the elimination of the “extra level of representation”. What is cost of this approach? The cost is that discourse representation becomes a part of some mind representation, embedding in this way in the world model, an inevitable component of referential semantics. This cost, however, is no cost at all, but rather a possibility for the integration of the anti-psychologist formal semantics and the informal cognitive linguistics. As for computational linguistics, in its branch aiming at intelligent text processing, our theory offers an approach to machine translation, for instance, which relies on the simulation of the human translator’s mind

    Unification in Unification-based Grammar

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    Natural language software registry (second edition)

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