What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Michael is a janitor if and only if Jessica is working. It is overcast if and only if Jessica is working. It is overcast.
If Michael were a janitor, then Jessica is working. If it is overcast, then Jessica is working. If Jessica works, then Michael is a janitor. If Jessica works, then it is overcast.