unit element meaning in English

单位码元
单位元
单元码元

The checking method for the associative law of finite groups is discussed by programme . in the same time , the checking of dosure law , unit element and mverse element , is added into the program , so that it can check whethe a finite set is a group for the giving binary operation
用编程的方法讨论了群论中结合律的检查，同时把闭合律、单位元、逆元的检查也添进程序中，使得该程序能检查一个有限集合对所给二元运算是否成一个群