On Classes of Regular Languages Related to Monotone WQOs

  • Mizuhito Ogawa
  • Victor SelivanovEmail author
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 11612)


We study relationships of monotone well quasiorders to regular languages and \(\omega \)-languages, concentrating on decidability of the lattices of upper sets on words and infinite words. We establish rather general sufficient conditions for decidability. Applying these conditions to concrete natural monotone WQOs, we obtain new decidability results and new proofs of some known results.


Regular language Monotone WQO Lattice of upper sets Periodic extension Decidability Difference hierarchy 


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Authors and Affiliations

  1. 1.Japan Advanced Institute of Science and TechnologyNomiJapan
  2. 2.A.P. Ershov Institute of Informatics Systems SB RASNovosibirskRussia
  3. 3.Kazan Federal UniversityKazanRussia

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