Regularity of one-letter languages acceptable by 2-way finite probabilistic automata

  • Jānis Kaņeps
Part of the Lecture Notes in Computer Science book series (LNCS, volume 529)


R. Freivalds proved that the nonregular language {0m1m} can be recognized by 2-way probabilistic finite automata (2pfa) with arbitrarily high probability 1-ε (ε>0). We prove that such an effect is impossible for one-letter languages: every one-letter language acceptable by 2pfa with an isolated cutpoint is regular.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • Jānis Kaņeps
    • 1
  1. 1.Institute of Mathematics and Computer ScienceThe University of LatviaRigaLatvia

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