If only one of the two conditions is met, we must accept union.
intersection
Generally speaking, the set of all elements belonging to A and B is called the intersection of A and B. 。
record
(pronounced "a to b")
Total sum
Generally speaking, the set composed of all elements belonging to A or B is called the union of A and B, and is recorded as
(pronounced "a and b")
Extended data:
The difference between intersection and union:
1, with different properties.
Intersection is the gathering or interweaving of different things or feelings; Combination is when two things know what they contain. Mathematically, generally speaking, for a given two sets A
and
Set b
The intersection of means that it contains all items that belong to both.
A
Belong to again
B
In set theory and other branches of mathematics, a set is not a set composed of all the elements of these sets, but does not contain other elements.
2. The essence is different
Intersection is intersection; Union is addition. The intersection of two sets has * * *, but it means that all works have it. Union means that two sets are merged into a * * * set in the form of
x
belong to
A
If and only if x
belong to
Ah Qi
x
belong to
B.
3. Expression differences
A
and
B
Intersection writing
"A∩B", a ∩ b = {x 丨 x∈ A and x ∈ b}; A and b together write "A∪B", that is, A∪B={x|x∈A, or x∈B}.