What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one x_6 for which if x_6 sleeps, then x_6 is listening to a song. For all x_6, x_6 will sleep if and only if x_6 will listen to a song.
For all x_6, if x_6 sleeps, then x_6 is listening to a song. For all x_6, if x_6 listens to a song, then x_6 is sleeping.