@InProceedings{niwinski_et_al:LIPIcs.STACS.2025.69, author = {Niwi\'{n}ski, Damian and Parys, Pawe{\l} and Skrzypczak, Micha{\l}}, title = {{A Dichotomy Theorem for Ordinal Ranks in MSO}}, booktitle = {42nd International Symposium on Theoretical Aspects of Computer Science (STACS 2025)}, pages = {69:1--69:18}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-365-2}, ISSN = {1868-8969}, year = {2025}, volume = {327}, editor = {Beyersdorff, Olaf and Pilipczuk, Micha{\l} and Pimentel, Elaine and Thắng, Nguy\~{ê}n Kim}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.STACS.2025.69}, URN = {urn:nbn:de:0030-drops-228942}, doi = {10.4230/LIPIcs.STACS.2025.69}, annote = {Keywords: dichotomy result, limit ordinal, countable ordinals, nondeterministic tree automata} }