在学习了空集的概念后 ,很多学生搞不清楚 0 ,{ 0 } , ,{ }之间的关系 ,一些学生甚至错误地认为 0 ={ 0 }= ={ } .0不是一个集合 .{ 0 } , ,{ }都为集合 ,其中 { 0 }为含有一个元素 0的集合 , 为不含任何元素的集合 ,{ }为含有一个元素 的集合 ,这里的 作为集合 { }的一 After learning the concept of the empty set, many students are not clear about the relationship between 0,{0},,{}, and some students even mistakenly believe that 0 ={ 0 }= ={ } .0 is not a collection.{ 0 } , ,{ } are collections, where { 0 } is a collection containing one element 0, a collection without any elements, and { } is a collection containing one element, here as a set { }