Weak and strong recognition by 2-way randomized automata

  • Andris Ambainis
  • Rūsiņš Freivalds
  • Marek Karpinski
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1269)


Languages weakly recognized by a Monte Carlo 2-way finite automaton with n states are proved to be strongly recognized by a Monte Carlo 2-way finite automaton with no(n) states. This improves dramatically over the previously known result by M.Karpinski and R.Verbeek [10] which is also nontrivial since these languages can be nonregular [5]. For tally languages the increase in the number of states is proved to be only polynomial, and these languages are regular.


Markov Chain Finite Automaton Minimal Cycle Input Word Deterministic Finite Automaton 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Andris Ambainis
    • 1
  • Rūsiņš Freivalds
    • 1
  • Marek Karpinski
    • 2
  1. 1.Institute of Mathematics and Computer ScienceUniversity of LatviaRigaLatvia
  2. 2.Department of Computer ScienceUniversity of BonnBonnGermany

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