A note on generators of the endomorphism semigroup of an infinite countable chain

Ilinka Dimitrova, Vítor H. Fernandes, Jörg Koppitz

In this note, we consider the semigroup $O(X)$ of all order endomorphisms of an infinite chain $X$ and the subset $J$ of $O(X)$ of all transformations $\alpha$ such that $|Im(\alpha )|=|X|$.…