ABSTRACT
This chapter discusses basic notions about sets and functions in more detail by establishing the basic results and developing the basic proof techniques. The union of a collection of sets consists of those objects that are elements of at least one set in the collection, whereas the intersection of a collection of sets consists of those objects that are elements of all the sets in the collection. The chapter defines three special classes of functions, such as injections, surjections, and bijections, and discusses the compositions of functions. It also includes some exercise problems related to the sets, relations, and functions.
