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 an astronaut or y is not a janitor. There is at least one y for which y is a janitor or y is not an astronaut.
For all y, if y were a janitor, then y is an astronaut. There is at least one y for which if y were an astronaut, then y is a janitor.