Xn是包含n个元素的全序集,SPn-是Xn上的降序严格部分变换半群,对4 n和2≤r≤n-2,证明了半群SK-(n,r)={α∈SPn-∶|Imα|≤r}是幂等元生成的,并且是由顶端Jr*的(r+1)S(n,r+1)个幂等元生成.
Let SP-n be the decreasing-order strictly partial transformations on a totally ordered finite set Xn.For 4≤n,2≤r≤n-2,the paper shows that the subsemigroup SK-(n,r)={α∈SP-n∶|Im α|≤r}is idempotent-generated and it is generated by the(r+1)S(n,r+1) idempotents in J*r.