It is probably the case that Julius is gray. It is highly likely that Jeff went to the office. We doubt that Brian is a frog.
It is probably not the case that either Jeff went to the office, or Julius is gray.
It is probably not the case that either Jeff went to the office, or Julius is gray.
It is highly likely that either Jeff went to the office, or Julius is gray.
Either Jeff went to the office, or Julius is gray.