On the semigroup of monoid endomorphisms of the semigroup ${\mathcal{C}}_{+}(a,b)$

Oleg Gutik, Sher-Ali Penza

Let ${\mathcal{C}}_{+}(a,b)$ be the submonoid of the bicyclic monoid which is studied in \cite{Makanjuola-Umar=1997}. We describe monoid endomorphisms of the semigroup $\mathscr{C}_{…