What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is not cloudy. Joseph is a janitor if and only if Sarah is driving a car. It is cloudy if and only if Sarah is driving a car. Joseph is a janitor or it is windy.
If Joseph were a janitor, then Sarah is driving a car. If it is cloudy, then Sarah is driving a car. If Sarah drives a car, then Joseph is a janitor. If Sarah drives a car, then it is cloudy. Sarah is not driving a car.