context: It is certain that Greg is a swan. It is probably not the case that John picked up the milk. It is impossible that Julius is gray. It is probable that if Greg is a swan, or John picked up the milk, then Sandra got the apple. We doubt that if Greg is a swan, and John picked up the milk, then Brian is a frog. It is almost certain that if Greg is a swan, and Julius is gray, then Lily is yellow.
hypothesis: It is certain that either Julius is gray, or Greg is a swan.
valid_hypothesis: It is certain that either Julius is gray, or Greg is a swan.
invalid_hypothesis: We doubt that either Julius is gray, or Greg is a swan.
hypothesis_assertion: Either Julius is gray, or Greg is a swan.