What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one z_1 for which z_1 is a police officer if and only if z_1 will drive a car. For all z_1, if z_1 were a police officer, then z_1 is driving a car.
There is at least one z_1 for which if z_1 were a police officer, then z_1 is driving a car. There is at least one z_1 for which if z_1 drives a car, then z_1 is a police officer.