ABSTRACT
I am always hungry after teaching evening classes. I know that by the time I get home, everyone in the house will be asleep and, with a family as large as mine, there will not be leftovers from supper. So I often stop at a convenience store for a late night snack and sometimes a tank of gasoline. I have two choices of convenience stores: one near the university and another near my house. Both are part of the same chain and they are nearly identical in what they sell and how they are arranged.
