Congruences on Order-preserving Partial Transformation Semigroups
Yang Hao-bo · Journal of Hangzhou Teachers College · 2007
Let n be a positive integer greater than 1.Let POn denote the semigroup consisting of order-preserving partial transformations on a chain [n] with length n,under composition.In this paper,every congruence on the semigroup POn is shown to be a Rees congruence.