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The Tractability Frontier for NFA Minimization

  • Henrik Björklund
  • Wim Martens
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5126)

Abstract

We essentially show that minimizing finite automata is NP-hard as soon as one deviates from the class of deterministic finite automata. More specifically, we show that minimization is NP-hard for all finite automata classes that subsume the class that is unambiguous, allows at most one state q with a non-deterministic transition for at most one alphabet symbol a, and is allowed to visit state q at most once in a run. Furthermore, this result holds even for automata that only accept finite languages.

Keywords

Minimization Problem Regular Expression Vertex Cover Regular Language Deterministic Finite Automaton 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Henrik Björklund
    • 1
  • Wim Martens
    • 1
  1. 1.TU Dortmund 

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