Results 1 
8 of
8
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 ..."
Abstract

Cited by 48 (3 self)
 Add to MetaCart
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
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 ..."
Abstract

Cited by 23 (7 self)
 Add to MetaCart
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.
The PushDown Method to Optimize Chain Logic Programs (Extended Abstract)
 In ICALP’95
, 1995
"... The critical problem of finding efficient implementations for recursive queries with bound arguments offers many open challenges of practical and theoretical import. We propose a novel approach that solves this problem for chain queries, i.e., for queries where bindings are propagated from arguments ..."
Abstract

Cited by 5 (3 self)
 Add to MetaCart
The critical problem of finding efficient implementations for recursive queries with bound arguments offers many open challenges of practical and theoretical import. We propose a novel approach that solves this problem for chain queries, i.e., for queries where bindings are propagated from arguments in the head to arguments in the tail of the rules, in a chainlike fashion. The method, called pushdown, is based on the fact that a chain query can have associated a contextfree language and a pushdown automaton recognizing this language can be emulated by rewriting the query as a particular factorized leftlinear program. The proposed method generalizes and unifies previous techniques such as the `counting' and `right, left, mixedlinear' methods. It also succeeds in reducing many nonlinear programs to queryequivalent linear ones.
Grammars And Automata To Optimize Chain Logic Queries
, 1999
"... The critical problem of finding efficient implementations for recursive queries with bound arguments offers many open challenges of practical and theoretical import. In particular, we need methods that are effective for the general case, such as nonlinear programs, as well as for specialized cases, ..."
Abstract

Cited by 4 (0 self)
 Add to MetaCart
The critical problem of finding efficient implementations for recursive queries with bound arguments offers many open challenges of practical and theoretical import. In particular, we need methods that are effective for the general case, such as nonlinear programs, as well as for specialized cases, such as leftrecursive linear programs. In this paper, we propose a novel approach that solves this problem for chain queries, i.e., for queries where bindings are propagated from arguments in the head to arguments in the tail of the rules, in a chainlike fashion. The method, called pushdown method, is based on the fact that each chain query can be associated with a contextfree language, and that a pushdown automaton recognizing this language can be emulated by rewriting the query as a particular factorized leftlinear program. The proposed method generalizes and unifies previous techniques such as the `counting' and `right, left, mixedlinear' methods. It succeeds in reducing many nonlinear programs to queryequivalent linear ones.
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 ..."
Abstract

Cited by 4 (0 self)
 Add to MetaCart
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...
AMOS: A Natural Language Parser Implemented As A Deductive Database In LOLA
 in LOLA in Ramakrishnan R.: Applications of Logic Databases, Kluwer Academic
, 1995
"... In this paper we present the setoriented bottomup parsing system AMOS which is a major application of the deductive database system LOLA. AMOS supports the morphosyntactical analysis of old Hebrew and has now been operationally used by linguists for a couple of years. The system allows the declar ..."
Abstract

Cited by 3 (1 self)
 Add to MetaCart
In this paper we present the setoriented bottomup parsing system AMOS which is a major application of the deductive database system LOLA. AMOS supports the morphosyntactical analysis of old Hebrew and has now been operationally used by linguists for a couple of years. The system allows the declarative specification of Definite Clause Grammar rules. Due to the setoriented bottomup evaluation strategy of LOLA it is particularly well suited to the analysis of language ambiguities. 1 INTRODUCTION In this paper the setoriented bottomup natural language parsing system AMOS, a major application of the deductive database system LOLA [3, 4], is presented. The AMOS system serves for the morphosyntactical analysis of old Hebrew text and is intensively used by linguists. A grammar for old Hebrew [12] has been formalized as a Definite Clause Grammar (DCG) and represented as a LOLA program. The Definite Clause Grammar formalism and the evaluation of the corresponding logic programs by a P...
Coping With Ambiguity in Decorated Parse Forests
 In Coping with Linguistic Ambiguity in Typed Feature Formalisms, Proceedings of a Workshop held at ECAI 92
, 1992
"... A parse forest is a spaceefficient representation of a number of parse trees. Parse forests are produced by various contextfree parsing algorithms. This paper presents an algorithm to manipulate a parse forest according to a contextfree grammar extended with parameters over a finite domain. This ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
A parse forest is a spaceefficient representation of a number of parse trees. Parse forests are produced by various contextfree parsing algorithms. This paper presents an algorithm to manipulate a parse forest according to a contextfree grammar extended with parameters over a finite domain. This algorithm combines the disambiguation of ambiguous sentences, which is necessarily userdirected, with the verification of context dependencies, which is done automatically. The algorithm is very timeefficient. Furthermore, our approach allows the storage of a parse forest instead of separate parse trees to store the result of parsing an ambiguous sentence. 1 Introduction Large subsets of natural languages can be described using contextfree grammars extended with some kind of parameter mechanism, e.g. affix grammars, attribute grammars, and definite clause grammars. This paper deals with affix grammars over a finite lattice (AGFLs). The parameters in AGFLs are called affixes. AGFLs are a ...