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 y for which if y were a janitor, then y is taking a plane. For all y, if y were a janitor, then y is a bartender. For all y, if y were a bartender, then y is a janitor.
There is at least one y for which if y were a bartender, then y is taking a plane. For all y, y is a janitor if and only if y is a bartender. For all y, y is a bartender if and only if y is a janitor.