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

  title={A Tentative Approach for the Wadge-Wagner Hierarchy of Regular Tree Languages of Index [0, 2]},
  author={Jacques Duparc and Kevin Fournier},
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 \([0,2]\). 
1 Citations

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  • J. Duparc
  • Mathematics
    Journal of Symbolic Logic
  • 2001
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