Regular order-preserving transformation semigroups
Yupaporn Kemprasit, Thawhat Changphas · Bulletin of the Australian Mathematical Society · 2000
The semigroupOT(X) of all order-preserving total transformations of a finite chainXis known to be regular. We extend this result to subchains ofZ; and we characterise whenOT(X) is regular for an intervalXinR. We also consider the corresponding idea for partial transformations of arbitrary chains and posets.