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14
FiniteState Approximation Of Phrase Structure Grammars
, 1991
"... Phrasestructure grammars are an effective representation for important syntactic and semantic aspects of natural languages , but are computationally too demanding for use as language models in realtime speech recognition. An algorithm is described that computes finitestate approximations for cont ..."
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Cited by 49 (1 self)
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Phrasestructure grammars are an effective representation for important syntactic and semantic aspects of natural languages , but are computationally too demanding for use as language models in realtime speech recognition. An algorithm is described that computes finitestate approximations for contextfree grammars and equivalent augmented phrasestructure grammar formalisms. The approximation is exact for certain contextfree grammars generating regular languages, including all leftlinear and rightlinear contextfree grammars. The algorithm has been used to construct finitestate language models for limiteddomain speech recognition tasks.
Towards a Uniform Formal Framework for Parsing
 Current Issues in Parsing Technology
, 1991
"... Introduction Many of the formalisms used to define the syntax of natural (and programming) languages may be located in a continuum that ranges from propositional Horn logic to full first order Horn logic, possibly with nonHerbrand interpretations. This structural parenthood has been previously rem ..."
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Cited by 48 (3 self)
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Introduction Many of the formalisms used to define the syntax of natural (and programming) languages may be located in a continuum that ranges from propositional Horn logic to full first order Horn logic, possibly with nonHerbrand interpretations. This structural parenthood has been previously remarked: it lead to the development of Prolog [Col78, Coh88] and is analyzed in some detail in [PerW80] for ContextFree languages and Horn Clauses. A notable outcome is the parsing technique known as Earley deduction [PerW83]. These formalisms play (at least) three roles: descriptive: they give a finite and organized description of the syntactic structure of the language, analytic: they can be used to analyze sentences so as to retrieve a syntactic structure (i.e. a representation) from which the meaning can be extracted, generative: they can also be used as the specification of the concrete representation of sentences from a more
Parsing Incomplete Sentences
, 1988
"... An efficient contextfree parsing algorithln is preseuted that can parse sentences with unknown parts of unknown length. It produc in finite form all possible parses (often infinite in number) that could account for the missing parts. The algorithm is a variation on the construction due to Earl ..."
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Cited by 29 (2 self)
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An efficient contextfree parsing algorithln is preseuted that can parse sentences with unknown parts of unknown length. It produc in finite form all possible parses (often infinite in number) that could account for the missing parts. The algorithm is a variation on the construction due to Earley. ltowever, its presentation is such that it can readily be adapted to any chart parsing schema (top down, bottomup, etc...).
Generalized LeftCorner Parsing
 In Sixth Conference of the European Chapter of the Association for Computational Linguistics, Proceedings of the Conference
, 1993
"... We show how techniques known from generalized LR parsing can be applied to leftcorner parsing. The esulting parsing algorithm for contextfree grammars has some advantages over generalized LR parsing: the sizes and generation times of the parsers are smaller, the produced output is more compa ..."
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Cited by 23 (7 self)
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We show how techniques known from generalized LR parsing can be applied to leftcorner parsing. The esulting parsing algorithm for contextfree grammars has some advantages over generalized LR parsing: the sizes and generation times of the parsers are smaller, the produced output is more compact, and the basic parsing technique can more easily be adapted to arbitrary contextfree grammars.
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 17 (10 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.
LPDA: Another look at Tabulation in Logic Programming
 Proceedings of the International Conference on Logic Programming
, 1994
"... The Logic PushDown Automaton (LPDA) is introduced as an abstract operational model for the evaluation of logic programs. The LPDA can be used to describe a significant number of evaluation strategies, ranging from the topdown OLD strategy to bottomup strategies, with or without prediction. Two ty ..."
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Cited by 4 (0 self)
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The Logic PushDown Automaton (LPDA) is introduced as an abstract operational model for the evaluation of logic programs. The LPDA can be used to describe a significant number of evaluation strategies, ranging from the topdown OLD strategy to bottomup strategies, with or without prediction. Two types of dynamic programming, i.e. tabular, interpretation are defined, one being more efficient but restricted to a subclass of LPDAs. We propose to evaluate a logic program by first compiling it into a LPDA according to some chosen evaluation strategy, and then applying a tabular interpreter to this LPDA. This approach offers great flexibility and generalizes Magic Set transformations. It explains in a more intuitive way some known Magic Set variants and their limits, and also suggests new developments. Keywords: logic programs, tabulation, memoing, magicset, dynamic programming, pushdown automata. 1 Introduction The recent years have seen the popularity of (at least) two approaches to i...
Interprocedural Analyses: A Comparison
 Journal of Logic Programming (JLP
, 1999
"... We present a framework for program analysis of languages with procedures which is general enough to allow for a comparison of various approaches to interprocedural analysis. Our framework is based on a smallstep operational semantics and subsumes both frameworks for imperative and for logic languag ..."
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Cited by 4 (2 self)
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We present a framework for program analysis of languages with procedures which is general enough to allow for a comparison of various approaches to interprocedural analysis. Our framework is based on a smallstep operational semantics and subsumes both frameworks for imperative and for logic languages. We consider reachability analysis, that is, the problem of approximating the sets of program states reaching program points. We use our framework in order to clarify the impact of several independent design decisions on the precision of the analysis. Thus, we compare intraprocedural forward accumulation with intraprocedural backward accumulation. Furthermore, we consider both relational and functional approaches. While for relational analysis the accumulation strategy makes no difference in precision, we prove for functional analysis that forward accumulation may lose precision against backward accumulation. Concerning the relative precision of relational analyses and corresponding funct...
Tabulation of Automata for Tree Adjoining Languages
, 1999
"... We try to provide a common framework to clarify the relationships between different automata and their associated tabulation techniques for Tree Adjoning Languages, a subclass of Mildly ContextSensitive Languages. We have chosen Logic Pushdown Automata working with Linear Indexed Grammars as a sta ..."
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Cited by 1 (0 self)
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We try to provide a common framework to clarify the relationships between different automata and their associated tabulation techniques for Tree Adjoning Languages, a subclass of Mildly ContextSensitive Languages. We have chosen Logic Pushdown Automata working with Linear Indexed Grammars as a starting point. Several tabulation techniques for different parsing strategies are proposed and compared with previous approaches. 1 Introduction The class of Mildly ContextSensitive Languages (MCSL) is placed between contextfree languages and contextsensitive languages. An important subclass in MCSL is that of Tree Adjoining Languages, which can be described by several grammar formalisms which have been shown to be equivalent with respect to their weak generative capacity (VijayShanker and Weir, 1994): Tree Adjoining Grammars (Joshi and Schabes, 1997), Linear Indexed Grammars (Gazdar, 1987), Head Grammars (Pollard, 1984) and Combinatory Categorial Grammars (Steedman, 1986). Several parsi...
Logic Finite Automata
"... . In this paper we generalize the concept of a finite state automaton, essentially by replacing terminal and nonterminal symbols by first order terms and identity checking by unification. We arrive at the concept of a logic finite automaton. Ignoring a conceptual distinction in the treatment of inpu ..."
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Cited by 1 (1 self)
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. In this paper we generalize the concept of a finite state automaton, essentially by replacing terminal and nonterminal symbols by first order terms and identity checking by unification. We arrive at the concept of a logic finite automaton. Ignoring a conceptual distinction in the treatment of input, logic finite automata may also be regarded as logic grammars with a rightlinear skeleton. The concept is then discussed from these two perspectives. We first consider logic finite automata over an input alphabet of constants, regarding logic finite automata as classical automata. Among other results the four classes from the ChomskyHierarchy are characterized by means of syntactic restrictions on logic finite automata. Turning then to logic languages we discuss two notions of determinismcalled ground and strict determinismfor logic finite automata which take sequences of first order terms as input. We show that for some languages which may be recognized by logic finite automata backt...
How to build quickly an efficient implementation of the domain Prop with DyALog.
"... DyALog, a tabular logic program evaluator with a modular architecture, is used to develop quickly an efficient interpreter for logic programs with boolean constraints [CLP(Boole)programs]. This is done by a coupling DyALog with PECOS, a constraint solver over finite domains. This experiment, done in ..."
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DyALog, a tabular logic program evaluator with a modular architecture, is used to develop quickly an efficient interpreter for logic programs with boolean constraints [CLP(Boole)programs]. This is done by a coupling DyALog with PECOS, a constraint solver over finite domains. This experiment, done in the context of Abstract Interpretation of logic programs, illustrates the "genericity" of our approach for developing interpretations on various abstract domains and for various semantics. 1 Introduction DyALog 1 is an evaluator of logic programs which ensures answer completeness, computation sharing, and, for functionfree programs, termination. All kinds of resolution strategies can be simulated via the use of Logic Push Down Automata [LPDA]. Dynamic Programming techniques (especially tabulation) are used to evaluate these automata[BVdlC92]. The underlying theory and the current modular architecture of DyALog offer the possibility of using DyALog as an generic evaluator of programs o...