University of Guilan Journal of Algebra and Related Topics 2345-3931 9 2 2021 12 01 On Closed Homotypical Varieties of Semigroups 83 95 5187 10.22124/jart.2021.18949.1255 EN Sh. Abbas Department of Mathematics, Aligarh Muslim University, Aligarh, India W. Ashraf Department of Mathematics, Aligarh Muslim University, Aligarh, India N. Noor Rafiquee Department of Mathematics, Aligarh Muslim University, Aligarh, India Journal Article 2021 02 16 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 $axy=xayx^2$. Zigzag equations Homotypical variety Identity and Closed https://jart.guilan.ac.ir/article_5187_d3e0ea1a8a98a336c730ae64260a828e.pdf