What does set A and set B mean in discrete mathematics

Inside the math set.

a=b means:

The elements in both sets are identical.

For example, set A is.

Set B is. Then you can get it.

a=2，b=3

or a = 3, b = 2

It should be noted that the discrete mathematical proof process needs to explain the laws of operation (it is best to refine it to each step, and the = in the diagram can also be written as an equivalent sign (double arrow)).

There is only one element x in one-two, and there is only one element in }, the first one is x, and the element in the second set is a set, and the two sets have no intersection, that is, -}=, obviously one and two are right.

Three, x< (including symbols will not hit, just use this) x, then obviously xfour empty set does not contain any elements, so naturally there will not be any elements.

5 is a subset of any set, so right.

6 is a set of units, and its elements are only one, and it is also a set, that is, so natural.

Is 7 true..? Right?

8 is similar.

In short, lz is a point of right and wrong, and the set can also be used as an element of other sets.

By the meaning of the subject there is a dijection:

f:a→cg:b→d

Order h: a b c d

That is, h() = can be proved to be single shot, full shot.

So h has bipolarity.

So a b c d

a c, indicating what is the relationship between the two sets, and it should be clearly explained.

Difference Difference Definition: In general, let a and b be two sets, consisting of all elements that belong to a and do not belong to b, called set a minus set b (or the difference between set a and set b), similarly, for set a

b, we call the set the difference between a and b, denoted as a b denoted as a b (or a b), i.e. a b (or a b

b a is called the difference between b and a.

Difference difference definition: In general, let a and b be two sets, the set composed of all the elements that belong to a and do not belong to b, called set a minus set b (or the difference between set a and set b), similarly, for sets, we call the set the difference between a and b, denoted as a b and denoted as a b (or a b), that is, a b (or a b).

b a is called the difference between b and a.

In the mathematical set, a=b means:

The elements in both sets are identical.

For example, set A is.

Set B is. Then we get a=2, b=3

or a = 3, b = 2