What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_9, if x_9 were a janitor, then x_9 is a nurse. For all x_9, x_9 is a janitor or x_9 will drive a car. For all x_9, x_9 is not a nurse. There is at least one x_9 for which if x_9 were a nurse, then x_9 is a janitor.
For all x_9, x_9 is not a janitor. There is at least one x_9 for which x_9 is a nurse if and only if x_9 is a janitor. There is at least one x_9 for which x_9 is a janitor if and only if x_9 is a nurse.