The maximal subsemigroups of semigroups of transformations preserving or reversing the orientation on a finite chain
Ilinka Dimitrova, Vítor Hugo Fernandes, Jörg Koppitz · Publicationes Mathematicae Debrecen · 2012
The study of the semigroups OP n , of all orientation-preserving transformations on an n-element chain, and ORn, of all orientation-preserving or orientationreversing transformations on an n-element chain, has began in [17] and [5].In order to bring more insight into the subsemigroup structure of OP n and OR n , we characterize their maximal subsemigroups.