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 Charles doesn't drive a car, then Charles is listening to a song. Linda is taking a plane if and only if Charles is driving a car. Linda is not taking a plane. If Charles listens to a song, then Charles is not driving a car.
Charles is not driving a car if and only if Charles is listening to a song can be inferred via the biconditional introduction rule. Charles is listening to a song if and only if Charles is not driving a car can be inferred via the biconditional introduction rule. If Linda takes a plane, then Charles is driving a car can be inferred via the biconditional elimination rule. If Charles drives a car, then Linda is taking a plane can be inferred via the biconditional elimination rule. Charles is not driving a car can be inferred via the biconditional elimination rule.