In this paper we initiate an investigation into the class of meet semilattices endowed with endomorphism. A consideration subdirectly irreducible algebras leads to a description subclass those (S;∧,k)(S;∧,k) in which (S;∧)(S;∧) is semilattice and kk endomorphism on SS characterised by property k⩾idSk⩾idS. We particularly show that such algebra if only it chain one following forms ⋯<aj&am...

In this paper we give suitable notions of congruences and subdirectly irreducible algebras for the class of quasi-modal algebras introduced in [1]. We also prove some characterizations of subdirectly irreducible algebras following the similar results given by G. Sambin [5] for modal algebras.

We prove that a finite unary algebra with at least two operation symbols is a homomorphic image of a (finite) subdirectly irreducible algebra if and only if the intersection of all its subalgebras which have at least two elements is nonempty. We are concerned with the following question: Which algebras are homomorphic images of subdirectly irreducible algebras? A necessary condition, discovered...

It is proved that the variety of representable idempotent commutative residuated lattices is locally finite. The n-generated subdirectly irreducible algebras in this variety are shown to have at most 3n+1 elements each. A constructive characterization of the subdirectly irreducible algebras is provided, with some applications. The main result implies that every finitely based extension of posit...