On the number of polynomials of a universal algebra, I
On the reconstruction of Boolean algebras from their automorphism groups.
On the subsemilattices of first-order definable and openly first-order definable congruences of the congruence lattice of a universal algebra.
On weak automorphisms of quasi-linear algebras
On weakly rigid monounary algebras
Partial monounary algebras with common quasi-endomorphisms
Proper automorphisms of universal algebras.
Regularity and transitivity of local-automorphism semigroups of locally finite forests
Retracts and monomorphism monoids in semigroup varieties.
Rigid Boolean Algebras
Shift-automorphism methods for inherently nonfinitely based varieties of algebras
Simultaneous representations in discrete structures
Solution of the problem of directly decomposable homomorphisms
Some monounary algebras with EKP
An algebra is said to have the endomorphism kernel property (EKP) if every congruence on is the kernel of some endomorphism of . Three classes of monounary algebras are dealt with. For these classes, all monounary algebras with EKP are described.
Span in incidence structures of independent sets defined on projective space
Special incidence structures of type
Special incidence structures of type . II.
Strong endomorphism kernel property for finite Brouwerian semilattices and relative Stone algebras
We show that all finite Brouwerian semilattices have strong endomorphism kernel property (SEKP), give a new proof that all finite relative Stone algebras have SEKP and also fully characterize dual generalized Boolean algebras which possess SEKP.
Strong endomorphism kernel property for monounary algebras
All monounary algebras which have strong endomorphism kernel property are described.
Strong retracts of unary algebras
This paper introduces the notion of a strong retract of an algebra and then focuses on strong retracts of unary algebras. We characterize subuniverses of a unary algebra which are carriers of its strong retracts. This characterization enables us to describe the poset of strong retracts of a unary algebra under inclusion. Since this poset is not necessarily a lattice, we give a necessary and sufficient condition for the poset to be a lattice, as well as the full description of the poset.