What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one z for which if z were a cashier, then z is a janitor. For all z, z is not a janitor. For all z, z will climb a mountain. For all z, z is a cashier or z is an artist.
There is at least one z for which z is not a cashier.