associative operation的意思|示意

Mathematics a set with an associative binary operation under which the set is closed, which contains an identity element and an inverse for every element in the set.

群：二元结合运算为闭合的数学集合，具有单位元素。集合中每一元素都有逆元素。

This one is slightly more complicated but USES a Ruby hash (associative array) to simplify the reduction operation (see Listing 5).

虽然此应用程序稍微有些复杂，但是使用Ruby hash(关联阵列)可简化reduce操作(请参考清单5)。