context: Chances are about even that Julius is a swan. There is almost no chance that Greg is a lion. Chances are about even that Lily is yellow. It is unlikely that if either Lily is yellow, or Greg is a lion, then Mary dropped the milk. There is a very good chance that if Greg is a lion, and Julius is a swan, then John left the apple. It is highly likely that if Julius is a swan, and Greg is a lion, then Bill went to the office.
hypothesis: It is certain that either Lily is yellow, or Julius is a swan.
valid_hypothesis: Chances are about even that either Lily is yellow, or Julius is a swan.
invalid_hypothesis: It is certain that either Lily is yellow, or Julius is a swan.
hypothesis_assertion: Either Lily is yellow, or Julius is a swan.