A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is
There are several generalizations to universal algebras of the notion "The group 31 is an extension of the group ii by the group G ". In this paper we study three such generalizations and the corresponding products of classes of algebraicsystems. Various results are presented. One such theorem characterizes the weakly congruence regular varieties admitting extensions of a particular sort. Another result gives, under a weak congruence permutability condition, an equational basis for the varietydoi:10.1090/s0002-9947-1984-0719672-2 fatcat:wrlaywqdhjd2njur33iklpmrgy