In mathematics, set z stands for "integer set", which means a set of all integers. Mathematically, the sum of several things with the same nature is called a set. Set the abbreviation set. The definition of "set" in high school mathematics textbooks is: "Generally speaking, we call the research object an element, and the whole composed of some elements is called a set".

The set z represents the set of all integers, including positive integers, 0 and negative integers. All integers form an integer set, which is a number ring. In the integer system, zero and positive integers are collectively called natural numbers. -1, -2, -3, ..., -n, (n is a non-zero natural number) are all negative integers. Positive integers, zero integers and negative integers form an integer system. Integers exclude decimals and fractions.

Mathematical set is a basic concept in mathematics. The basic concept is a concept that cannot be defined by other concepts, and it is also a concept that cannot be defined by other concepts. The concept of set can be defined in an intuitive and axiomatic way.

Classification and composition of integer sets: Integers include positive integers, negative integers and 0. The set of all positive integers is called positive integer set, which is usually represented by the symbol N+ (or n). The set of negative integers and zeros is called natural number set (also called non-negative integer set), which is usually represented by the symbol n. A negative integer set is a set of negative integers, which is represented by the symbol Z- (or Z _).

Representation method of set

1. enumeration: All elements in the collection are enumerated one by one, and are enclosed by braces "8" to represent the collection. This method of representing a collection is called enumeration. Enumeration is generally used to indicate that when the number of elements is limited and the number of elements is small, its characteristic is to clearly display the elements in the collection, which is a common representation.

2. Description: Write the general symbols indicating the elements of this set and their value (or variation) range with braces, and then draw a vertical line. Write down the same characteristics of this group of elements after the vertical line. This method of representing a set with the * * * same characteristics of the elements contained in the set is called description.

3. Graphic method: A set is represented as a closed curve, number axis and venn diagram coordinate system.