Most of what we did in Chapters  6 and   7 was concerned with operations on two sets. In general, we may have two or three sets, as many sets as there are integers, or even more sets than that. We’ll need a new definition and special notation. In this chapter, we will introduce the notation that will allow us to keep track of these sets. The chapter includes plenty of examples and exercises (with complete solutions) as well as problems for practice.