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A Tentative Approach for the Wadge-Wagner Hierarchy of Regular Tree Languages of Index [0, 2]

  • Jacques Duparc
  • Kevin Fournier
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9118)

Abstract

We provide a hierarchy of tree languages recognised by nondeterministic parity tree automata with priorities in \(\{0,1,2\}\), whose length exceeds the first fixed point of the \(\varepsilon \) operation (that itself enumerates the fixed points of \(x\mapsto \omega ^x\)). We conjecture that, up to Wadge equivalence, it exhibits all regular tree languages of index \([0,2]\).

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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Department of Information Systems Faculty of Business and EconomicsUniversity of LausanneLausanneSwitzerland
  2. 2.Équipe de Logique MathématiqueUniversité Paris DiderotParis Cedex 13France

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