An easy proof of Greibach normal form
Information and Control
Formal languages
Grail: a C++ library for automata and expressions
Journal of Symbolic Computation - Special issue on “algorithms: implementation, libraries and use”
Dagwood: a system for manipulating polynomials given by straight-line programs
ACM Transactions on Mathematical Software (TOMS)
Derivatives of Regular Expressions
Journal of the ACM (JACM)
A New Normal-Form Theorem for Context-Free Phrase Structure Grammars
Journal of the ACM (JACM)
A List Structure Form of Grammars for Syntactic Analysis
ACM Computing Surveys (CSUR)
Theory of Computation: A Primer
Theory of Computation: A Primer
Introduction to Formal Language Theory
Introduction to Formal Language Theory
The Theory of Parsing, Translation, and Compiling
The Theory of Parsing, Translation, and Compiling
PODP '96 Proceedings of the Third International Workshop on Principles of Document Processing
Greibach Normal Form Transformation, Revisited
STACS '97 Proceedings of the 14th Annual Symposium on Theoretical Aspects of Computer Science
On the complexity of grammar and language problems.
On the complexity of grammar and language problems.
Grammar transformations based on regular decompositions of context-free derivations.
Grammar transformations based on regular decompositions of context-free derivations.
A normal form for XML documents
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
A normal form for XML documents
ACM Transactions on Database Systems (TODS)
Attribute grammars for unranked trees as a query language for structured documents
Journal of Computer and System Sciences
Simplifying XML schema: single-type approximations of regular tree languages
Proceedings of the twenty-ninth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
XML with incomplete information
Journal of the ACM (JACM)
Generating, sampling and counting subclasses of regular tree languages
Proceedings of the 14th International Conference on Database Theory
Complexity of Decision Problems for XML Schemas and Chain Regular Expressions
SIAM Journal on Computing
The complexity of text-preserving XML transformations
Proceedings of the thirtieth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
On the midpoint of a set of XML documents
DEXA'05 Proceedings of the 16th international conference on Database and Expert Systems Applications
Simplifying XML Schema: Single-type approximations of regular tree languages
Journal of Computer and System Sciences
Hi-index | 5.23 |
We investigate the complexity of a variety of normal-form transformations for extended context-free grammars, where by extended we mean that the set of right-hand 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 context-free objects just as Grail does for regular objects. Our results generalize known complexity bounds for context-free grammars but do so in nontrivial ways. Specifically, we introduce a new representation scheme for extended context-free grammars (the symbol-threaded expression forest), a new normal form for these grammars (dot normal form) and new regular expression algorithms. Copyright 2001 Elsevier Science B.V.