What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z_2, z_2 is an electrician or z_2 will drive a car. Susan is a janitor or Richard is not driving a car. If it is overcast, then Susan is a janitor. Richard is not an electrician or it is overcast.
If Richard drives a car, then Susan is a janitor.