A Classification of Regressive Transformation Semigroups on Chains

Patanee Udomkavanich, Phichet Jitjankarn

For each subchain $X^{\prime }$ of a chain $X$, let $T_{RE}(X,X^{\prime })$ denote the semigroup under composition of all full regressive transformations, $\alpha :X\to X^{\prime }$ satisfying $x\alpha \le x$…