What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Richard is listening to a song if and only if John is writing a letter. James is not a poet. If Richard listens to a song, then it is snowing. If it snows, then James is a poet.
It is not snowing. If Richard listens to a song, then John is writing a letter. If John writes a letter, then Richard is listening to a song.