If A and B are two sets taken from some universe U, then the union of A and B written AUB, is the set containing any element of either A or B.
A U B = {X \(X · A) V(X ·B)}
Example.
A = { 1,2,3}
B = { 4,5,6}
AUB = {1,2,3,4,5,6}
Note: The definition for union says that in order for an element to be part of the solution set for AU B it must only be a member of either set A or of set B. The definition of the disjunction “or” also requires that only one statement p or q be true.
