What is a non null true subset and what does a non null true subset mean

Any set is a subset of itself, and a non-true subset is the original set A is a true subset of b, but a is not an empty set, and a≠b is said to be a non-null true subset of b. If there are n elements in b, then b has 2 n subsets, and non-empty true subsets (2 n)-2.

A is a true subset of b, but a is not an empty set, then a is a non-empty true subset of b.

Non-null true subset = total number of true subsets - 1 = total number of subsets - 2 For example: set a = is a true subset of set b= Because set a is not an empty set, it can also be said that set a is a non-empty true subset of set b.

The meaning of non-empty subsets is similar.

That is, set a is a subset of set b, but set b is not an empty set, so it is not an empty subset.

Note: The difference between a non-empty subset and a non-empty true subset is that the subset can be equal while the true subset cannot be equal.

An empty set is a subset of any set that's mathematically prescribed, just remember it.

The system comprises: a program label acquisition unit, which is used for collecting program names and program labels; the input unit is used for entering at least one program name, space area, time area and generating a call instruction; The program tag database summarizes and stores the program tags according to the program name and receives the call instruction to export the program tag data source; The program ratings database stores the program information and viewing information as the ratings data source, and receives the call instruction to export it; the viewing space construction unit, and the receiving data source construction has a program label viewing space; The program tag association rule analysis unit analyzes the association rules of program tags. The system of the present invention can embody the association rules of multiple characteristics of television programs, sufficient data feedback and accurate generation of program labels.

The word "set" has a similar meaning to the words "whole", "class", "group", etc., which we are familiar with in our daily life. For example, "the whole of a math book", "the whole of people on the earth", "the whole of all stationery", and so on can be seen as a collection of "objects".

All kinds of things that we see, hear, smell, touch, and think of, or some abstract symbols, can be seen as objects. Generally speaking, if we look at some different objects that can be determined as a whole, we say that this whole is a set (or set) made up of the whole of these objects.

Sets are a basic concept in mathematics, let's start with, for example, a book in a bookcase makes a set, students in a classroom make a set, and all real numbers make up a set. In general, the so-called set (referred to as "set") refers to the totality of things with a certain specific nature, and the things that make up this set are called the elements of the set (referred to as "yuan"). Collections are usually represented by uppercase letters, and elements are represented by lowercase letters.

For example, a a, i.e., element a belongs to set a

A non-empty true subsetIt's just a series of numbers apartEmpty setother than the true subset.

For two sets A and B, if any of the accompanying elements in Set A are elements in Set B, we say that the two sets have an inclusion relationship, and we say that Set A is a subset of Set B, and if there are several or more elements in Set B that do not belong to Set A, and all the elements in Set A are stupid to Set B.

Then we say that set A is a true subset of set B, and a set that does not contain elements is called an empty set, which is denoted as . A prescription is a subset of any set.

An empty set is a subset of any collection, which is a stipulation. When a set is a non-empty set, its subset is not only the empty set, but also the non-empty subset, which is the non-empty subset, for example, a {1,2}, its subset is: empty set, {1}, {2}, {1,2}.

The last three are all non-empty subsets.

A true subset is a subset that does not contain all the elements, that is, some elements are not in this subset, for example, the {1} and {2} above are both true subsets of a.