The European Society for Research in Mathematics Education was founded in 1998. Since then, not a single institution or an individual from the areas of the former Yugoslavia have, yet joined the… (More)

We give a complete description of subdirectly irreducible rings with involution satisfying x = x for some positive integer n. We also discuss ways to apply this result for constructing lattices of… (More)

A class of algebras is said to be globally determined if any two members of that class having isomorphic power algebras are isomorphic. In 1984, Y. Kobayashi proved that semilattices are globally… (More)

The concept of σ-reflexive semigroups is due to Chacron and Thierrin in 1972. In the present paper we discuss σ-reflexive semigroups with apartness. We prove some fundamental properties of these… (More)