What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all y, y is not an office clerk. For all y, if y were a bartender, then y is an office clerk. For all y, y is an office clerk if and only if y is a bartender.
For all y, y is not a bartender. For all y, if y were an office clerk, then y is a bartender. For all y, if y were a bartender, then y is an office clerk. For all y, y is not a bartender.