What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: If Richard listens to a song, then William is an artist. William is an artist and Joseph is driving a car. If William were an artist, then Richard is listening to a song.
William is an artist can be inferred via the simplification rule. Joseph is driving a car can be inferred via the simplification rule. Richard is listening to a song if and only if William is an artist can be inferred via the biconditional introduction rule. William is an artist if and only if Richard is listening to a song can be inferred via the biconditional introduction rule.