context: It is certain that Mary picked up the apple. Chances are about even that Brian is a swan. We doubt that Julius is a swan. It is probably not the case that if either Mary picked up the apple, or Brian is a swan, then Lily is a rhino. It is probable that if Brian is a swan, and Mary picked up the apple, then Bernhard is gray. There is a very good chance that if Brian is a swan, and Mary picked up the apple, then Greg is a lion.
hypothesis: Chances are slight that brian is a swan, or Mary picked up the apple.
valid_hypothesis: It is certain that brian is a swan, or Mary picked up the apple.
invalid_hypothesis: Chances are slight that brian is a swan, or Mary picked up the apple.
hypothesis_assertion: Brian is a swan, or Mary picked up the apple.