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 it is windy, then Barbara is a mechanic. If Karen listens to a song, then it is windy. Charles is driving a car if and only if Barbara is a mechanic. If Charles drives a car, then Karen is listening to a song.
If Karen listens to a song, then Barbara is a mechanic can be inferred via the transitivity rule. If Charles drives a car, then it is windy can be inferred via the transitivity rule. If Charles drives a car, then Barbara is a mechanic can be inferred via the biconditional elimination rule. If Barbara were a mechanic, then Charles is driving a car can be inferred via the biconditional elimination rule.