What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_8, if x_8 works, then x_8 is listening to a song. For all x_8, if x_8 listens to a song, then x_8 is working. For all x_8, if x_8 works, then x_8 is listening to a song. Sarah is not listening to a song.
For all x_8, x_8 will work if and only if x_8 will listen to a song. For all x_8, x_8 will listen to a song if and only if x_8 will work. For all x_8, x_8 will listen to a song if and only if x_8 will work. For all x_8, x_8 will work if and only if x_8 will listen to a song.