“集合”是每一个高一学生碰到的第一个数学概念,集合是什么?集合有什么作用?集合像空气一样无所不在,像空气一样无比重要,像空气一样极为平凡,它又像空气一样,抓不住,摸不着.那它是一个什么概念呢?集合是一个不能给出明确定义的概念,它太基本了,就好比几何中的“点”、“线”、“面”一样,不能用更加基本的东西来定义它,只能用它去定义别的概念.不能给集合下定义,却可以描述它.一位渔民非常喜欢数学,但他怎么也想不明白集合 “Collection ” is the first mathematical concept that every freshman encounters. What is the collection? What is the role of the collection? The collection is as airy as the air, as extremely important as the air, as extraordinary as the air, The same as the air, can not grasp, can not touch. So what is it a concept? Set is a concept can not be given a clear definition, it is too basic, like the geometry of the “dot”, “line” , “Face”, you can not define it with something more basic, it can only be used to define other concepts, you can not define a collection, but you can describe it. A fisherman really likes math, but how does he I do not understand the collection