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MFCS
2004
Springer

Complexity of Decision Problems for Simple Regular Expressions

10 years 3 months ago
Complexity of Decision Problems for Simple Regular Expressions
We study the complexity of the inclusion, equivalence, and intersection problem for simple regular expressions arising in practical XML schemas. These basically consist of the concatenation of factors where each factor is a disjunction of strings possibly extended with ‘∗’ or ‘?’. We obtain lower and upper bounds for various fragments of simple regular expressions. Although we show that inclusion and intersection are already intractable for very weak expressions, we also identify some tractable cases. For equivalence, we only prove an initial tractability result leaving the complexity of more general cases open. The main motivation for this research comes from database theory, or more specifically XML and semi-structured data. We namely show that all lower and upper bounds for inclusion and equivalence, carry over to the corresponding decision problems for extended context-free grammars and single-type tree grammars, which are abstractions of DTDs and XML Schemas, respective...
Wim Martens, Frank Neven, Thomas Schwentick
Added 02 Jul 2010
Updated 02 Jul 2010
Type Conference
Year 2004
Where MFCS
Authors Wim Martens, Frank Neven, Thomas Schwentick
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