What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, z will sleep if and only if z is an office clerk. For all z, z is not a lawyer. For all z, if z drives a car, then z is an office clerk. There is at least one z for which z is a lawyer or z will drive a car.
There is at least one z for which z will drive a car. For all z, if z sleeps, then z is an office clerk. For all z, if z were an office clerk, then z is sleeping.