context: It is probable that Greg is gray. We believe that Gertrude is a wolf. We believe that Bernhard is a frog.
hypothesis: It is impossible that bernhard is a frog, and Greg is gray.
valid_hypothesis: Chances are about even that bernhard is a frog, and Greg is gray.
invalid_hypothesis: It is impossible that bernhard is a frog, and Greg is gray.
hypothesis_assertion: Bernhard is a frog, and Greg is gray.