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25
Improved leftcorner chart parsing for large contextfree grammars
 In Proceedings of the Sixth International Workshop on Parsing Technologies
, 2000
"... We develop an improved form of leftcorner chart parsing for large contextfree grammars, introducing improvements that result in significant speedups compared to previouslyknown variants of leftcorner parsing. We also compare our method to several other major parsing approaches, and find that ou ..."
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Cited by 19 (1 self)
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We develop an improved form of leftcorner chart parsing for large contextfree grammars, introducing improvements that result in significant speedups compared to previouslyknown variants of leftcorner parsing. We also compare our method to several other major parsing approaches, and find that our improved leftcorner parsing method outperforms each of these across a range of grammars. Finally, we also describe a new technique for minimizing the extra information needed to efficiently recover parses from the data structures built in the course of parsing. 1
An Optimal Tabular Parsing Algorithm
 In 32nd Annual Meeting of the Association for Computational Linguistics, Proceedings of the Conference
"... In this paper we relate a number of parsing algorithms which have been developed in very different areas of parsing theory, and which include deterministic algorithms, tabular algorithms, and a parallel algorithm. We show that these algorithms are based on the same underlying ideas. ..."
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Cited by 18 (11 self)
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In this paper we relate a number of parsing algorithms which have been developed in very different areas of parsing theory, and which include deterministic algorithms, tabular algorithms, and a parallel algorithm. We show that these algorithms are based on the same underlying ideas.
Increasing the applicability of LR parsing
 In Third International Workshop on Parsing Technologies
, 1993
"... In this paper we discuss a phenomenon present in some contextfree grammars, called hidden left recursion. We show that ordinary LR parsing according to hidden leftrecursive grammars is not possible and we indicate a range of solutions to this problem. One of these solutions is a new parsing techni ..."
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Cited by 17 (6 self)
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In this paper we discuss a phenomenon present in some contextfree grammars, called hidden left recursion. We show that ordinary LR parsing according to hidden leftrecursive grammars is not possible and we indicate a range of solutions to this problem. One of these solutions is a new parsing technique, which is a variant of traditional LR parsing. This new parsing technique can be used both with and without lookahead and the nondeterminism can be realized using backtracking or using a graphstructured stack. 1
Efficient Tabular LR Parsing
 IN 34TH ANNUAL MEETING OF THE ASSOCIATION FOR COMPUTATIONAL LINGUISTICS
, 1996
"... We give a new treatment of tabular LR parsing, which is an alternative to Tomita's generalized LR algorithm. The advantage is twofold. Firstly, our treatment is conceptually more attractive because it uses simpler concepts, such as grammar trans formations and standard tabulation techniq ..."
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Cited by 14 (7 self)
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We give a new treatment of tabular LR parsing, which is an alternative to Tomita's generalized LR algorithm. The advantage is twofold. Firstly, our treatment is conceptually more attractive because it uses simpler concepts, such as grammar trans formations and standard tabulation techniques also know as chart parsing. Secondly, the static and dynamic complexity of parsing, both in space and time, is significantly reduced.
Conventional Natural Language Processing in the NWO Priority Programme on Language and Speech Technology
, 1996
"... ..."
Probabilistic parsing strategies
 In 42nd Annual Meeting of the Association for Computational Linguistics
, 2004
"... We present new results on the relation between purely symbolic contextfree parsing strategies and their probabilistic counterparts. Such parsing strategies are seen as constructions of pushdown devices from grammars. We show that preservation of probability distribution is possible under two condi ..."
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Cited by 6 (1 self)
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We present new results on the relation between purely symbolic contextfree parsing strategies and their probabilistic counterparts. Such parsing strategies are seen as constructions of pushdown devices from grammars. We show that preservation of probability distribution is possible under two conditions, viz. the correctprefix property and the property of strong predictiveness. These results generalize existing results in the literature that were obtained by considering parsing strategies in isolation. From our general results we also derive negative results on socalled generalized LR parsing. 1
A Customized Grammar Workbench
 English Language Corpora: Design, Analysis and Exploitation, Papers from the thirteenth International Conference on English Language Research on Computerized Corpora
, 1992
"... In this paper we describe the ideas behind the Grammar Workbench (GWB). The GWB is one of a series of tools for the development of AGFLs (affix grammars over a finite lattice) for natural languages. Its functions comprise a specialised editor, computation of properties, a random generator of sentenc ..."
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Cited by 5 (5 self)
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In this paper we describe the ideas behind the Grammar Workbench (GWB). The GWB is one of a series of tools for the development of AGFLs (affix grammars over a finite lattice) for natural languages. Its functions comprise a specialised editor, computation of properties, a random generator of sentences, and special functions to provide an overview of a grammar. This paper discusses the functions of the GWB, the grammatical formalism AGFLs, and the AGFL project. We also discuss the relationship between the complete development environment for AGFLs and other development environments, both for other grammatical formalisms and for computer programs. 1 Introduction Formal grammars for natural languages tend to become unmanageable as they get larger. Similar problems occur in the development of large computer programs. To overcome these problems with large programs, a number of techniques have been invented in the field of software engineering to ffl structure programs so as to permit deco...
Survey of Parallel ContextFree Parsing Techniques
, 1997
"... This report describes research done in the context of a subproject of the HPCN project IMPACT. The IMPACT project is headed by the ING bank and is founded by the organization for High Performance Computing and Networking (HPCN). The aim of the specific subproject, in the context of which this report ..."
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Cited by 4 (3 self)
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This report describes research done in the context of a subproject of the HPCN project IMPACT. The IMPACT project is headed by the ING bank and is founded by the organization for High Performance Computing and Networking (HPCN). The aim of the specific subproject, in the context of which this report has been written, is to develop (techniques for) natural language interfaces to information resources, focusing on the use of highperformance computers to achieve acceptable response times. This report is part of the "Parallel Parsing I" research topic. IMPACTNLI19971 ii Preface IMPACT IMPACTNLI19971 IMPACT iii Contents Preface i 1 Introduction 1 2 Basics 3
Efficient Decoration of Parse Forests
, 1993
"... This paper deals with affix grammars over a finite lattice (AGFLs). The parameters in AGFLs are called affixes. AGFLs are a simple formalism but have still been proved powerful enough for the description of various natural languages [20]. Contextfree parsing can be implemented very efficiently by c ..."
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Cited by 3 (2 self)
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This paper deals with affix grammars over a finite lattice (AGFLs). The parameters in AGFLs are called affixes. AGFLs are a simple formalism but have still been proved powerful enough for the description of various natural languages [20]. Contextfree parsing can be implemented very efficiently by constructing parse forests. A parse forest is a concise representation of a number of parse trees for an ambiguous sentence. Parse forests can be constructed in polynomial time and require polynomial space for storage, measured in the length of the input sentence. In this paper, the extra parameters of extended contextfree grammars are used to impose restrictions (called context dependencies) on the allowable parse trees. Contextfree parsing must therefore be augmented to calculate the parameters. Affix values for AGFLs can be evaluated efficiently because the domains are finite. The rejection of parse trees based on violated context dependencies is more complicated if parse trees are merged into parse forests. Because of the ambiguous nature of natural language, grammars describing natural languages are necessarily also ambiguous, and therefore context dependencies cannot determine a unique parse tree for every sentence. Instead, some humancomputer interaction is necessary to find the intended parses of sentences.
HighPerformance MultiPass Unification Parsing
, 2002
"... Parsing natural language is an attempt to discover some structure in a text (or textual representation) generated by a person. This structure can be put to a variety of uses, including machine translation, grammar conformance checking, and determination of prosody in texttospeech tasks. Recent the ..."
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Cited by 2 (0 self)
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Parsing natural language is an attempt to discover some structure in a text (or textual representation) generated by a person. This structure can be put to a variety of uses, including machine translation, grammar conformance checking, and determination of prosody in texttospeech tasks. Recent theories of Syntax use Unification to better describe the intricacies of natural language [137]. For parsing systems, unification techniques have been either added to a contextfree base system [152, 40, 4, 23], or replaced the contextfree base entirely [118, 135, 45] (possibly putting it back later [136]). The seemingly small step of adding unification has opened a Pandora’s Box of computational complexity, increasing the difficulty of the problem from polynomial [48] to somewhere between NPcomplete and intractable, depending on the details of the unification system and how it was added [10]. Worse, unification on a contextfree base parser can break the packing technique used to address the problem of ambiguity, leading to exponential blowups of the parser’s performance in both space and time in practice. I propose