Dietmar Berwanger, Erich Grädel, Giacomo Lenzi. On the Variable Hierarchy of the Modal µ-Calculus. In Julian C. Bradfield, editor, Computer Science Logic, 16th International Workshop, CSL 2002, 11th Annual Conference of the EACSL, Edinburgh, Scotland, UK, September 22-25, 2002, Proceedings. Volume 2471 of Lecture Notes in Computer Science, pages 352-366, Springer, 2002. [doi]
Abstract is missing.