Remarks on Generalized Post Correspondence Problem

نویسندگان

  • Tero Harju
  • Juhani Karhumäki
  • Daniel Krob
چکیده

It is shown that Post Correspondence Problem remains undecidable even in the case where one of the morphisms is xed. Accordingly the generalized PCP is undecidable even in the case where both of the morphisms are xed, and, moreover, the cardinality of their domain alphabet is 7. In particular, GPCP(7) is undecidable. On the other hand, GPCP(2) is not only decidable, but, as we show here, its all solutions can be eeectively found.

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تاریخ انتشار 1996