Definability by Weakly Deterministic Regular Expressions with Counters is Decidable

  • Markus LatteEmail author
  • Matthias Niewerth
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9234)


We show that weakly deterministic regular expressions with counters (WDREs) —as they are used in XML Schema— are at most exponentially larger than equivalent DFAs. As a consequence, the problem, whether a given DFA is equivalent to any WDRE, is decidable in EXPSPACE.


Normal Form Regular Expression Regular Language Parse Tree Alphabet Symbol 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Universität BayreuthBayreuthGermany

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