What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is windy, then Elisabeth is playing tennis. If Mary were a janitor, then it is sunny. It is windy if and only if it is sunny. If Elisabeth plays tennis, then Mary is a janitor.
If it is windy, then Mary is a janitor. If Elisabeth plays tennis, then it is sunny. If it is windy, then it is sunny. If it is sunny, then it is windy.