context: We doubt that Greg is a rhino. It is improbable that Lily is a frog. It is highly likely that Sandra took the milk. It is probably the case that if either Sandra took the milk, or Greg is a rhino, then Brian is gray. Chances are about even that if Lily is a frog, and Sandra took the milk, then Fred dropped the apple. There is a very good chance that if either Sandra took the milk, or Greg is a rhino, then Mary went to the bedroom.
hypothesis: Chances are about even that either Brian is gray, or Sandra took the milk.
valid_hypothesis: Chances are about even that either Brian is gray, or Sandra took the milk.
invalid_hypothesis: It is almost certain that either Brian is gray, or Sandra took the milk.
hypothesis_assertion: Either Brian is gray, or Sandra took the milk.