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 a bartender. For all z, z will listen to a song or z is not a server. For all z, if z listens to a song, then z is a server. For all z, if z were a server, then z is a bartender.
For all z, z is not a server can be inferred via the universal modus tollens rule. For all z, if z listens to a song, then z is a bartender can be inferred via the universal transitivity rule. For all z, if z were a server, then z is listening to a song can be inferred via the universal rewriting rule.