Generalized PCP is decidable for marked morphisms

  • Vesa Halava
  • Tero Harju
  • Mika Hirvensalo
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1684)


We prove that the generalized Post Correspondence Problem (GPCP) is decidable for marked morphisms. This result gives as a corollary a shorter proof for the decidability of the binary PCP, proved in 1982 by Ehrenfeucht, Karhumäki and Rozenberg.


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  1. 1.
    A. Ehrenfeucht, J. Karhumäki, and G. Rozenberg. The (generalized) Post correspondence problem with lists consisting of two words is decidable. Theoretical Computer Science, 21(2):119–144, 1982.zbMATHCrossRefMathSciNetGoogle Scholar
  2. 2.
    V. Halava, M. Hirvensalo and R. de Wolf. Decidability and Undecidability of Marked PCP. STACS’99 (C. Meinel and S. Tison, eds.), Lecture Notes in Comput. Sci, vol 1563, Springer-Verlag, 1999, pp. 207–216.Google Scholar
  3. 3.
    T. Harju and J. Karhumäki. Morphisms. In Handbook of Formal Languages, volume 1, 439–510. edited by G. Rozenberg and A. Salomaa, eds. Springer-Verlag, Berlin, 1997.Google Scholar
  4. 4.
    Y. Matiyasevich and G. Sènizergues. Decision problems for semi-Thue systems with a few rules. In Proceedings of the 11th IEEE Symposium on Logic in Computer Science, pages 523–531, 1996.Google Scholar
  5. 5.
    E. L. Post. A variant of a recursively unsolvable problem. Bulletin of the American Mathematical Society, 52:264–268, 1946.zbMATHMathSciNetCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Vesa Halava
    • 1
  • Tero Harju
    • 2
  • Mika Hirvensalo
    • 3
    • 4
  1. 1.Turku Centre for Computer ScienceTurkuFinland
  2. 2.Department of MathematicsUniversity of TurkuTurkuFinland
  3. 3.Department of MathematicsUniversity of TurkuTurkuFinland
  4. 4.Turku Centre for Computer ScienceFinland

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