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 is not a police officer. There is at least one z for which z will go running. For all z, if z goes running, then z is a police officer. For all z, if z were a police officer, then z is running.
Since the premises are contradictory, we can infer anything from them.