Abstract

J. P lonka at WSP in Opole, in 1980 and 1981. We shall consider algebras o type : T ! N; E, R, S denote the set of all identities of type and the set of all regular identities of type , respectively . If is a set of identities of type , then E() denotes the set of all identities which can be proved from ; R() = \ R, S() = \ S. denotes the variety generated by . Similarly, for a given variety V of algebras of type we shall consider varieties R and S dened by the set R of all regular identities satised in V and the set S of all symmetric identities satised in V , respectively