What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_15, if x_15 reads a book, then x_15 is listening to a song. Linda is playing a game if and only if Joseph is sleeping. Joseph is sleeping if and only if Robert is listening to a song. Linda is not playing a game.
If Linda plays a game, then Joseph is sleeping. If Joseph sleeps, then Robert is listening to a song. If Joseph sleeps, then Linda is playing a game. If Robert listens to a song, then Joseph is sleeping. Joseph is not sleeping.