What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, y will take a plane or y will not listen to a song. For all y, y will listen to a song. There is at least one y for which y will sleep.
There is at least one y for which y will sleep and y will listen to a song. There is at least one y for which y will listen to a song and y will sleep. For all y, if y listens to a song, then y is taking a plane.