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

@inproceedings{Duparc2015ATA,
title={A Tentative Approach for the Wadge-Wagner Hierarchy of Regular Tree Languages of Index [0, 2]},
author={Jacques Duparc and Kevin Fournier},
booktitle={DCFS},
year={2015}
}
• Published in DCFS 25 June 2015
• Computer Science
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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