State Complexity of Projected Languages

  • Galina Jirásková
  • Tomáš Masopust
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6808)


This paper discusses the state complexity of projected regular languages represented by incomplete deterministic finite automata. It is shown that the known upper bound is reachable only by automata with one unobservable transition, that is, a transition labeled with a symbol removed by the projection. The present paper improves this upper bound by considering the structure of the automaton. It also proves that the new bounds are tight, considers the case of finite languages, and presents several open problems.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Galina Jirásková
    • 1
  • Tomáš Masopust
    • 2
    • 3
  1. 1.Mathematical InstituteSlovak Academy of SciencesKošiceSlovak Republic
  2. 2.CWIAmsterdamThe Netherlands
  3. 3.Institute of MathematicsCzech Academy of SciencesBrnoCzech Republic

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