Some properties of Umar semigroups: isomorphism theorems, ranks and maximal inverse subsemigroups

• Main Authors: Bernd Billhardt, Jintana Sanwong, Worachead Sommanee
• Format: Journal
• Published: 2018
• Subjects: Mathematics
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85046012547&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/58807
• Institution: Chiang Mai University

© 2018 Springer Science+Business Media, LLC, part of Springer Nature In a paper published in 1994, Umar defined an interesting class of transformation semigroups which naturally generalizes the Vagner one-point completion of the symmetric inverse semigroup. In this paper we prove some isomorphism th...