(1) Faculty of Mathematical Sciences, Ferdowsi University of Mashhad, Mashhad, Iran;(2) Department of Mathematics, Sistan and Baloochestan University, Zahedan, Iran;(3) Department of Mathematics, Birjand University, Birjand, Iran
Abstract:
In this paper we study the concept of -isologisms among the -marginal extensions of groups, with respect to a given variety of groups . We also give some equivalent conditions under which two extensionsare -isologic. Received: 9 January 2002
-isologisms among the 
-marginal extensions of groups, with respect to a given variety of groups 
. We also give some equivalent conditions under which two extensionsare 
-isologic. Received: 9 January 2002