context: It is unlikely that Brian is a lion. There is almost no chance that Daniel dropped the apple. There is almost no chance that Greg is yellow. We doubt that if Greg is yellow, or Brian is a lion, then Sandra left the milk. It is highly likely that if either Greg is yellow, or Brian is a lion, then Lily is white. It is almost certain that if Greg is yellow, and Daniel dropped the apple, then Mary got the football.
hypothesis: It is impossible that lily is white, and Daniel dropped the apple.
valid_hypothesis: It is impossible that lily is white, and Daniel dropped the apple.
invalid_hypothesis: Chances are about even that lily is white, and Daniel dropped the apple.
hypothesis_assertion: Lily is white, and Daniel dropped the apple.