1. Example 1.  There are a lot of different cars at the car dealership: Hondas, Toyotas, Buicks, Fords, Cadillacs, Mazdas . . . 

   Function f exposes the name of the car maker to each car.

   In this case the set A is the set of cars at the car dealership;  Set B is the set of the car makers names.




2.  Example 2.  There are 35 students in the class. Each student has its own first name:  John, Michael, Alisa, Linda, Huan, and so on . . . 

    Function f exposes the first name to each of the students.

    In this case the set A is the set of students in the class; set B is the set of their first names.