What is the mathematical symbol for the unique values of union of two sets?

Question

Let's say you have two sets: A=[875 900 925 950 975 1000] and B=[825 850 875 900 925 950]. You'd like find the set of unique elements after the union sets A and B. In Matlab you can use the unique function and obtain the result:

A=[875 900 925 950 975 1000];
B=[825 850 875 900 925 950];
C=unique([A,B]);
>> C
C =
825 850 875 900 925 950 975 1000

How to write the unique function in the mathematical notation?

update.

I have tried: $A \bigcup B = \{x: (x \in A \vee x \in B) \}.$ In Matlab the union function gives the same result:

C = union(A,B)
C =
 825 850 875 900 925 950 975 1000

Answer 1

Edited answer: after running the OP's example in MATLAB, it appears that the object of interest simply is $$ A\cup B. $$ e.g. with A and B as specified, unique([A, B]) yields

825 850 875 900 925 950 975 1000