1, the set of all non-negative integers is usually called the set of non-negative integers (or the set of natural numbers), and is recorded as n.
2. Exclude the set of 0 from the set of non-negative integers, also known as the set of positive integers, and record it as N+ (or N*).
3. The set of all integers is usually called the set of integers, denoted as Z. ..
4. The set of all rational numbers is usually referred to as rational number set for short, and is denoted as Q. ..
5. The set of all real numbers is usually referred to as the set of real numbers for short, and is recorded as R. ..
6. the complex set is counted as C.
Extended data:
1, a set refers to a set of concrete or abstract objects with certain properties, which is called an element of a set. For example, the collection of all China people, its element is every China person. We usually use uppercase letters such as A, B, S, T, ... to represent the set, and lowercase letters such as A, B, X, Y, ... to represent the elements in the set.
2. There are two relationships between elements and sets: "attribution" and "non-attribution".
3. Operation of sets:
(1) set commutative law: a ∩ b = b ∩ a; A∪B=B∪A .
(2) Set association law: (a ∩ b) ∩ c = a ∩ (b ∩ c); (A∪B)∪C=A∪(B∪C).
(3) Set distribution law: a ∩ (b ∪ c) = (a ∪ b) ∩ (a ∪ c); A ∪( B∪C)=(A∪B)∪( A∪C).
References:
Baidu Encyclopedia _ Mathematics Collection