中文摘要：

根据已有的关于左不可数语言以及(n,k)-语言的研究成果.本文考虑当k=2时,(n,2)-语言和左-(n,2)-语言的一些性质,得出:(1)设A,B是阶分别为k1和k2的左-(n,2)-语言,则AB是阶为k1+k2的左-(n,2)-语言;(2)AB是(n,2)-语言(或左-(n,2)-语言),若A是左奇异语言,则B是(n,2)-语言(或左-(n,2)-语言);(3)左-(n,2)-语言的集合在连接运算,并集,交集和补集运算下是封闭的.

英文摘要：

Based on the existing research of noncounting languages ,left-noncounting and (n ,k)-languages .This paper focus on k=2 ,and propose the following properties on (n ,2)-languages and left-(n ,2)-languages :(1) Let A ,B be left-(n ,2)-languages with the order of k1 and k2 re-spectively .Then A B is a left-(n ,2)-language with the order of k1 + k2 ;(2) If A B is a (n ,2)-language (or a left (n ,2)-language) and A is a left singular language ,then B is a (n ,2)-lan-guage (or a left (n ,2)-language);(3)The class of all left-(n ,2)-languages is closed under the concatenation and Boolean operation of union ,intersection and complementation .