context: 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.
hypothesis: It is impossible that brian is a swan, and Greg is a frog.
valid_hypothesis: It is impossible that brian is a swan, and Greg is a frog.
invalid_hypothesis: There is a better than even chance that brian is a swan, and Greg is a frog.
hypothesis_assertion: Brian is a swan, and Greg is a frog.