context: We believe that Brian is a lion. It is likely that Bernhard is a swan. There is a better than even chance that Jeff dropped the apple.
hypothesis: It is impossible that either Bernhard is a swan, or Brian is a lion.
valid_hypothesis: Chances are about even that either Bernhard is a swan, or Brian is a lion.
invalid_hypothesis: It is impossible that either Bernhard is a swan, or Brian is a lion.
hypothesis_assertion: Either Bernhard is a swan, or Brian is a lion.