Inside the Class of REGEX Languages

  • Markus L. Schmid
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7410)


We study different possibilities of combining the concept of homomorphic replacement with regular expressions in order to investigate the class of languages given by extended regular expressions with backreferences (REGEX). It is shown in which regard existing and natural ways to do this fail to reach the expressive power of REGEX. Furthermore, the complexity of the membership problem for REGEX with a bounded number of backreferences is considered.


Extended Regular Expressions REGEX Pattern Languages Pattern Expressions Homomorphic Replacement 


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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Markus L. Schmid
    • 1
  1. 1.Department of Computer ScienceLoughborough UniversityLoughboroughUnited Kingdom

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