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 a janitor if and only if y is a police officer. For all x_6, x_6 is a police officer.
For all y, if y were a janitor, then y is a police officer. For all y, if y were a police officer, then y is a janitor.