Marked PCP is decidable

Authors
Publication date 2001
Journal Theoretical Computer Science
Volume | Issue number 255 | 1-2
Pages (from-to) 193-204
Number of pages 12
Organisations
  • Interfacultary Research - Institute for Logic, Language and Computation (ILLC)
Abstract We show that the marked version of the Post Correspondence Problem, where the words on a list are required to differ in the first letter, is decidable. On the other hand, we prove that the PCP remains undecidable if we only require the words to differ in the first two letters. Thus we locate the decidability/undecidability-boundary between marked and 2-marked PCP.
Document type Article
Language English
Published at https://doi.org/10.1016/S0304-3975(99)00163-2
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