有限全变换半群的主S_n-正规子半群的幂等元秩

The Idempotent Rank of the Principal Sn-normal Semigroups

设T_n和S_n是X_n={1,2,…,n}上的全变换半群和对称群,α∈T_n\S_n,计算得到主S_n-正规子半群〈g^(-1)αg|g∈S_n〉的幂等元秩.

Let Tn and Sn be the full transformation semigroup and the symmetric group on a finite set Xn={1,2,…,n}.Letαbe the element of T n\S n,the idempotent rank of the main S n-normal subsemigroup〈g^-1αg|g∈Sn〉is obtained.