It is certain that John moved to the office. It is impossible that Brian is a swan. Chances are about even that Greg is a frog.
It is impossible that brian is a swan, and Greg is a frog.
It is impossible that brian is a swan, and Greg is a frog.
There is a better than even chance that brian is a swan, and Greg is a frog.
Brian is a swan, and Greg is a frog.