What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_7, x_7 is a bartender if and only if x_7 is a scientist. If William were a scientist, then Mary is working.
For all x_7, if x_7 were a bartender, then x_7 is a scientist. For all x_7, if x_7 were a scientist, then x_7 is a bartender.