@InProceedings{rabinovich_et_al:LIPIcs.MFCS.2020.80, author = {Rabinovich, Alexander and Tiferet, Doron}, title = {{Ambiguity Hierarchy of Regular Infinite Tree Languages}}, booktitle = {45th International Symposium on Mathematical Foundations of Computer Science (MFCS 2020)}, pages = {80:1--80:14}, 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.2020.80}, URN = {urn:nbn:de:0030-drops-127495}, doi = {10.4230/LIPIcs.MFCS.2020.80}, annote = {Keywords: automata on infinite trees, ambiguous automata, monadic second-order logic} }