The union of two sets is represented as A union B (AUB). Union of two sets comprises of all elements in the two sets with common elements in the sets occuring only once. For example, if A = {1, 3, 5, 7} and B = {1, 2, 4, 6} then A ∪ B = {1, 2, 3, 4, 5, 6, 7}. Union between more than two sets can be represented as AU(BUC) or (AUB)UC. The operations can be performed in any order. Given below is the union of set (AUB) formula for union of 2 or more sets.

A∪B = {a1,a2,a3,a4,...,an} with ai∈A or ai∈B,i=1,2,3,...n

Where,

A and B represents the set A and set B