设G是一群.πe(G)表示群G的元素阶的集合,mi:=|{g∈G|g的阶为i}|表示群G中i阶元个数,nse(G)={mi|i∈πe(G)}表示群G中同阶元的长度的集合.本文对单群A11给出了新的刻画,即证明了:GA11,当且仅当下面条件成立:(1)|G|=|A11|,(2)nse(G)=nse(A11).
Let G be a group.Denote by πe(G) the set of element orders of G.Let i∈πe(G).Denote by mi:=|{g∈G| the order of g is i}|,the size of the same order elements,and nse(G):={mi|i∈πe(G)|},the set of sizes of the same order elements.In this paper,we prove that group G is isomorphic to A11,if and only if the following hold:(1) |G|=|A11|,(2) nse(G)=nse(A11).