On Closed Homotypical Varieties of Semigroups

Document Type : Research Paper

Authors

Department of Mathematics, Aligarh Muslim University, Aligarh, India

Abstract

It is known that all subvarieties of the variety of all semigroups are not absolutely closed. So, we determine some closed homotypical varieties of semigroups determined by the identities  $axy=x^2ayx$, $axy=xa^2ya$, $axy=yay^2x$, $axy=xaya^2$, $axy=y^2ayx$ and $axy=xayx^2$.

Keywords