What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, if z drives a car, then z is drinking water. There is at least one z for which z will drive a car if and only if z is a police officer.
There is at least one z for which if z drives a car, then z is a police officer. There is at least one z for which if z were a police officer, then z is driving a car.