Note that there are some buttons associated with a floor $($these are to call the elevator to the floor$)$ and some buttons are associated with a car $($these are to select a destination floor$).$ Also note that doors are associated with floors $($these keep people from falling into the elevator shaft$)$ and doors associated with the car $($to keep people from falling out of the car$).$ When you enter or leave an elevator car, you are passing through two doors! Enter the multiplicities for some of these relations. Note that some of the values may be duplicated, and some of the values might not be used.