Embedding semigroups in \({\mathcal D}\)-trivial semigroups
The main purpose of this note is to show that to be embeddable in a congruence-free semigroup (without idempotents) which is \({\mathcal D}\)- trivial, that is, each \({\mathcal D}\)-class is a singleton, it is not sufficient for a semigroup itself to be \({\mathcal D}\)-trivial.
scientific article; zbMATH DE number 3935338