What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is raining or Susan is not climbing a mountain. It is not raining. It is raining if and only if Mary is listening to a song. If Mary listens to a song, then Susan is climbing a mountain.
Susan is not climbing a mountain. If Susan climbs a mountain, then it is raining. If it rains, then Mary is listening to a song. If Mary listens to a song, then it is raining. Mary is not listening to a song.