Suppose A is the set of natural numbers less than 10 and B is the set of even numbers less
than 10. If we consider the set of odd numbers less than 10, then the elements in the set belong
to set A, but not to the set B. This set is represented by A - B and read it as A difference B
Therefore, A - B = {1, 3, 5, 7, 9}.
Now we define the difference set of sets A and
B as the set of elements which belong to A but do not
belong to B. We denote the difference of A and B by
A – B or simply “A minus B”.