What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, if z were an artist, then z is a janitor. For all z, if z were happy, then z is an artist. Elisabeth is not an artist. For all z, if z were a janitor, then z is happy.
For all z, if z were an artist, then z is happy. For all z, if z were happy, then z is a janitor. For all z, if z were a janitor, then z is an artist.