A1 Refereed original research article in a scientific journal
Extension of the decidability of the marked PCP to instances with unique blocks
Authors: Halava V, Harju T, Karhumaki J, Latteux M
Publisher: ELSEVIER SCIENCE BV
Publication year: 2007
Journal:: Theoretical Computer Science
Journal name in source: THEORETICAL COMPUTER SCIENCE
Journal acronym: THEOR COMPUT SCI
Volume: 380
Issue: 3
First page : 355
Last page: 362
Number of pages: 8
ISSN: 0304-3975
DOI: https://doi.org/10.1016/j.tcs.2007.03.024
Abstract
In the Post Correspondence Problem (PCP) an instance (h, g) consists of two morphisms h and g, and the problem is to determine whether or not there exists a nonempty word w such that h(w) = g(w). Here we prove that the PCP is decidable for instances with unique blocks using the decidability of the marked PCP. Also, we show that it is decidable whether an instance satisfying the uniqueness condition for continuations has an infinite solution. These results establish a new and larger class of decidable instances of the PCP, including the class of marked instances. (c) 2007 Elsevier B.V. All rights reserved.
In the Post Correspondence Problem (PCP) an instance (h, g) consists of two morphisms h and g, and the problem is to determine whether or not there exists a nonempty word w such that h(w) = g(w). Here we prove that the PCP is decidable for instances with unique blocks using the decidability of the marked PCP. Also, we show that it is decidable whether an instance satisfying the uniqueness condition for continuations has an infinite solution. These results establish a new and larger class of decidable instances of the PCP, including the class of marked instances. (c) 2007 Elsevier B.V. All rights reserved.
UTU Research Portal