2001/21/2

Cardinalities of lattices of topologies of unars and some related topics

On the structure of halfdiagonal-halfterminal-symmetric categories with diagonal inversions

Some modifications of congruence permutability and dually congruence regular varietie

The semantical hyperunification problem

Minimal formations of universal algebras

Maximal column rank preservers of fuzzy matrices

Tree transformations defined by hypersubstitutions

Congruence classes in Brouwerian semilattices

Ring-like structures with unique symmetric difference related to quantum logic

The lattice of subvarieties of the biregularization of the variety of Boolean algebras