Infinite Solutions of Marked Post Correspondence Problem

  • Vesa Halava
  • Tero Harju
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2300)


In an instance of the Post Correspondence Problem we are given two morphisms h, g : A *B *. Here we prove that if the morphisms are marked, then it is decidable whether the instance has an infinite solution, i.e., whether or not there exists an infinite word ω such that h and g are comparable for all prefixes of ω. This problem is known to be undecidable in general for Post Correspondence Problem.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Vesa Halava
    • 1
    • 2
  • Tero Harju
    • 1
    • 2
  1. 1.Department of MathematicsUniversity of TurkuTurkuFinland
  2. 2.TUCSTurku Centre for Computer ScienceTurkuFinland

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