2023/06/01 by Jiulin Jin, Jin, Jiulin, Taijie You +1
Computer Science · Mathematics · #semigroups and automata theory #Mathematical Dynamics and Fractals #Advanced Differential Equations and Dynamical Systems
paper · pdf · doi:10.48550/arxiv.2306.00822
Suppose that X be a nonempty set. Denote by T(X) the full transformation semigroup on X. For \varnothing ≠ Z⊆ Y⊆ X, let T(X,Y,Z)=\α∈ T(X): Yα⊆ Z \. Then T(X,Y,Z) is a subsemigroup of T(X). In this paper, we characterize the regular elements of the semigroup T(X,Y,Z), and present a necessary and sufficient condition under which T(X,Y,Z) is regular. Furthermore, we investigate the abundance of the semigroup T(X,Y,Z) for the case Z\subsetneq Y\subsetneq X. In addition, we compute the cardinalities of T(X,Y,Z), \rm Reg(T(X,Y,Z)) and \rm E(T(X,Y,Z)) when X is finite, respectively.