集合论是现代数学的基础理论之一,集合语言几乎已成了数学的“基本语言”.但在中学阶段,对集合的子、交、并、补的概念及其运算规律,学生在学过之后,因未得到及时的应用,而往往容易忘却.殊不知,正是这些看似简单的概念和规律,如果运用得当,却能收到意想不到的效果. Set theory is one of the basic theories of modern mathematics. The language of assembly has become almost the “basic language” of mathematics. But in the middle school stage, the concepts of sub-set, intersection, union, and complement, and their operation rules, were studied after the students learned. Because it has not been applied in time, it is often easy to forget. As everyone knows, it is these seemingly simple concepts and laws. If used properly, they can receive unexpected results.