Protein phosphatase which antagonizes mitotic cyclin-dependent kinase nimX, the inactivation of which is essential for exit from mitosis. To access its substrates, is released from nucleolar sequestration during mitosis. Plays an essential in coordinating the nuclear division cycle with cytokinesis through the cytokinesis checkpoint. Involved in chromosome segregation, where it is required for meiosis I spindle dissambly as well as for establishing two consecutive chromosome segregation phases (By similarity). Required for the transcription of the two major endoglucanase genes eglA and eglB and growth on synthetic cellulose as the sole carbon source. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Does not localize to the nucleolus as its homologs do in S.cerevisiae and S.pombe. Accumulates within nuclei as they pass through interphase, displays a complex localization in mitosis, and localizes to the forming septum after mitosis is completed. Belongs to the protein-tyrosine phosphatase family. Non-receptor class CDC14 subfamily.