What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Linda is a writer or Joseph is driving a car. Charles is a mechanic if and only if James is taking a plane. If Joseph drives a car, then James is taking a plane. Charles is not a mechanic. Linda is not a writer or Jessica is listening to a song.
Joseph is driving a car or Jessica is listening to a song. If Charles were a mechanic, then James is taking a plane. If James takes a plane, then Charles is a mechanic. James is not taking a plane.