,                
                            
                    Jan Martens                
                    
            
                
    Creative Commons Attribution 3.0 Unported license
We study the relation of containment up to unknown regular resynchronization between two-way non-deterministic transducers. We show that it constitutes a preorder, and that the corresponding equivalence relation is properly intermediate between origin equivalence and classical equivalence. We give a syntactical characterization for containment of two transducers up to resynchronization, and use it to show that this containment relation is undecidable already for one-way non-deterministic transducers, and for simple classes of resynchronizations. This answers the open problem stated in recent works, asking whether this relation is decidable for two-way non-deterministic transducers.
@InProceedings{kuperberg_et_al:LIPIcs.MFCS.2020.58,
  author =	{Kuperberg, Denis and Martens, Jan},
  title =	{{Regular Resynchronizability of Origin Transducers Is Undecidable}},
  booktitle =	{45th International Symposium on Mathematical Foundations of Computer Science (MFCS 2020)},
  pages =	{58:1--58:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-159-7},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{170},
  editor =	{Esparza, Javier and Kr\'{a}l', Daniel},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2020.58},
  URN =		{urn:nbn:de:0030-drops-127255},
  doi =		{10.4230/LIPIcs.MFCS.2020.58},
  annote =	{Keywords: transducers, origin, resynchronisation, MSO, one-way, two-way, undecidability}
}