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What is a cross symbol?
In our daily life and study, we often see or use some symbols. Let's talk about what an intersection symbol is first.

The short answer intersection symbol is a mathematical symbol that we often use, and it is written as ∩. In set theory, let A and B be two sets, which are composed of all elements belonging to set A and set B. It is called the intersection of set A and set B, and it is called A ∩ B. Mathematically, the intersection of two sets A and B is a set that contains all elements belonging to A and B, but does not contain other elements.

In set theory, let A and B be two sets, which are composed of all elements belonging to set A and set B, called the intersection of set A and set B, and marked as A ∩ B. ..

Mathematically speaking, the intersection of two sets A and B is a set that contains all the elements belonging to A and B, but no other elements. The intersection of a and b is written as "A ∩B" Formally: X belongs to A ∩B if and only if X belongs to A and X belongs to B.

For example, the intersection of sets {1, 2,3} and {2,3,4} is {2,3}. The number 9 does not belong to the intersection of the prime set {2,3,5,7, 1 1} and the odd set {1, 3,5,7,9,1}.

If the intersection of two sets A and B is empty, that is, they have no common elements, then they do not intersect. More generally, intersection operations can be performed on multiple collections at the same time. For example, the intersection of sets a, b, c and d is a ∩ b ∩ c ∩ d = a ∩ (b ∩ (c ∩ d)). The intersection operation satisfies the associative law, that is, a ∩ (b ∩ c) = (a ∩ b) ∩ c c.