context: It is highly likely that Greg is yellow. It is probably the case that Mary went to the bedroom. It is highly likely that Bill put down the milk. It is likely that if either Bill put down the milk, or Mary went to the bedroom, then Sandra got the apple. Chances are about even that if Mary went to the bedroom, and Greg is yellow, then Lily is green. It is unlikely that if Mary went to the bedroom, and Bill put down the milk, then Brian is a frog.
hypothesis: It is almost certain that brian is a frog, and Bill put down the milk.
valid_hypothesis: It is improbable that brian is a frog, and Bill put down the milk.
invalid_hypothesis: It is almost certain that brian is a frog, and Bill put down the milk.
hypothesis_assertion: Brian is a frog, and Bill put down the milk.