Suppose that the students at Memorial Uni$-$

versity all live in either St$.$ Johns or Mount Pearl.

Let J be the set of students in St$.$ Johns, and P be the set of

students in Mount Pearl. Then the set of all students S $=$ J $\backslash$cup P $.$

We define class as a Boolean function taking two people as ar$-$

guments, which returns true if they are in a class together and

false if they are not. Also, the order of arguments does not matter