Hierarchies of one-way multihead automata languages

  • Marek Chrobak
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 194)


Let DPDA(k) (resp. NPDA(k)) be the class of languages recognized by one-way k-head deterministic (resp. nondeterministic) pushdown automata. The main result of this paper is that for each k>0 DPDA(k) ⪇ DPDA (k+1) and DPDA(k) ⪇ NPDA(k).


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Copyright information

© Springer-Verlag Berlin Heidelberg 1985

Authors and Affiliations

  • Marek Chrobak
    • 1
  1. 1.Institute of InformaticsWarsaw UniversityWarsawPoland

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