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