3 papers
math.RA2026
An extension theory and semidirect sums for nearrings
Stefan Veldsman
An extension theory for nearrings along the lines of the Schreier extension for groups and the Everett extension for rings is given. The semidirect sum of two nearrings is a specia…
math.RA2026
Free nearrings
Stefan Veldsman
An explicit construction of a free nearring as well as the free product (= coproduct) of two nearrings are given in the variety of all, not necessarily zero-symmetric, nearrings.
math.GN2022
The significance of the contributions of congruences to the theory of connectednesses and disconnectednesses for topological spaces and graphs
Stefan Veldsman
This is a survey of some of the consequences of the recently introduced congruences on the theory of connectednesses (radical classes) and disconnectednesses (semisimple classes) o…