What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If David were an artist, then it is windy. David is an artist if and only if Mary is a scientist. If it is not windy, then Karen is working. Mary is not a scientist. If it is windy, then David is an artist.
David is an artist if and only if it is windy. It is windy if and only if David is an artist. If David were an artist, then Mary is a scientist. If Mary were a scientist, then David is an artist. David is not an artist.