What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all z, z is not an astronaut. For all z, if z were an astronaut, then z is listening to a song. There is at least one z for which z is an astronaut or z will not listen to a song.
There is at least one z for which if z listens to a song, then z is an astronaut can be inferred via the existential rewriting rule.