Set is one of the basic concepts in mathematics. The sum of things with certain attributes is called a set, and elements are everything that constitutes a set. The branch of mathematics that studies the operations and properties of sets is called set theory or set theory. The definition of set is very broad.
It is not only limited to mathematics, but also widely used in production and life. And all things with specific attributes that make up a specific set can be called elements, so the definition of elements is also very broad.
Some specified objects are grouped together to form a set, where each object is called an element. The elements in the feature set have many functions, which will be explained below. Certainty For a given set, the elements in the set are certain, and any object is either an element of the given set or not. Example: Real numbers greater than 1 can form set anisotropy.
In any given set, any two elements are different objects, and when the same object is contained in a set, it is only one element. Disorder. The elements in the set are equal, and there is no order. So to judge whether two sets are the same, we only need to compare whether their elements are the same, and we don't need to examine whether the arrangement order is the same.
The relationship between an element and a given set
1, A belongs to the set A, which is expressed as an element of the set A and recorded as A ∈ A ..
2.A does not belong to the set A, which means that A is not an element of the set A, and it is recorded as A? Answer.