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Normal Form Algorithms for Extended ContextFree Grammars
 Theoretical Computer Science
, 2000
"... We investigate the complexity of a variety of normalform transformations for extended contextfree grammars, where by extended we mean that the set of righthand sides for each nonterminal in such a grammar is a regular set. The study is motivated by the implementation project GraMa which will p ..."
Abstract

Cited by 18 (2 self)
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We investigate the complexity of a variety of normalform transformations for extended contextfree grammars, where by extended we mean that the set of righthand sides for each nonterminal in such a grammar is a regular set. The study is motivated by the implementation project GraMa which will provide a C++ toolkit for the symbolic manipulation of contextfree objects just as Grail does for regular objects. Our results generalize known complexity bounds for contextfree grammars but do so in nontrivial ways. Specifically, we introduce a new representation scheme for extended contextfree grammars (the symbolthreaded expression forest), a new normal form for these grammars (dot normal form) and new regular expression algorithms. 1 Introduction In the 1960's, extended contextfree grammars were introduced, based on BackusNaur form, as a useful abbreviatory notation that made contextfree grammars easier to write. More recently, the Standardized General Markup Language (SGML...
Extended ContextFree Grammars and Normal Form Algorithms
, 1998
"... We investigate the complexity of a variety of normalform transformations for extended contextfree grammars, where by extended we mean that the set of righthand sides for each nonterminal in such a grammar is a regular set. The study is motivated by the implementation project GraMa which will prov ..."
Abstract

Cited by 3 (2 self)
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We investigate the complexity of a variety of normalform transformations for extended contextfree grammars, where by extended we mean that the set of righthand sides for each nonterminal in such a grammar is a regular set. The study is motivated by the implementation project GraMa which will provide a C++ toolkit for the symbolic manipulation of contextfree objects just as Grail does for regular objects. Our results generalize known bounds for contextfree grammars but do so in nontrivial ways. Specifically, we introduce a new representation scheme for extended contextfree grammars (the symbolthreaded expression forest), a new normal form for these grammars (dot normal form) and new regular expression algorithms. 1 Introduction in the 1960's, extended contextfree grammars were introduced, using BackusNaur form, as a useful abbreviatory notation that made contextfree grammars easier to write. More recently, the Standardized General Markup Language (SGML) [13] used a similar ab...
Transition Diagram Systems and Normal Form Algorithms
, 1998
"... We investigate the complexity of a variety of normalform transformations for transition diagram systems, which are a parsing view of extended contextfree grammars. A transition diagram system is a finite collection of finitestate machines each of which is labeled with a unique nonterminal symbol. ..."
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Cited by 1 (1 self)
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We investigate the complexity of a variety of normalform transformations for transition diagram systems, which are a parsing view of extended contextfree grammars. A transition diagram system is a finite collection of finitestate machines each of which is labeled with a unique nonterminal symbol. The study is motivated by the implementation project GraMa which will provide a C++ toolkit for the symbolic manipulation of contextfree objects just as Grail does for regular objects. 1 Introduction In the 1960's, extended contextfree grammars (as BackusNaur form) were introduced as a useful abbreviatory notation that made contextfree grammars easier to write. More recently, the Standardized General Markup Language (SGML) [17] used a similar abbreviatory notation to define extended contextfree grammars for documents. Currently, XML [4], which is a simplified version of SGML, is being promoted as the markup language for the web, instead of HTML (a specific grammar or DTD specified us...