Homogeneous monounary algebras
Homomorphic images of finite subdirectly irreducible unary 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.
Homomorphisms and strong homomorphisms of relational structures
Homomorphisms of algebras
A construction of all homomorphisms of an algebra with a finite number of operations into an algebra of the same type is presented that consists in replacing algebras by suitable mono-unary algebras (possibly with some nullary operations) and their homomorphisms by suitable homomorphisms of the corresponding mono-unary algebras. Since a construction of all homomorphisms between two mono-unary algebras is known (see, e.g., [6], [7], [8]), a construction of all homomorphisms of an arbitrary algebra...
Homomorphisms of machines. I
Homomorphisms of machines. II
Homomorphisms of unary algebras and of their expansions