context: We doubt that Greg is a lion. We doubt that Brian is a swan. It is probably the case that Julius is gray. It is improbable that if Greg is a lion, and Julius is gray, then Mary went to the hallway. There is little chance that if Greg is a lion, and Brian is a swan, then Sandra left the apple. There is a better than even chance that if Greg is a lion, and Brian is a swan, then John picked up the milk.
hypothesis: It is highly likely that john picked up the milk, or Brian is a swan.
valid_hypothesis: It is unlikely that john picked up the milk, or Brian is a swan.
invalid_hypothesis: It is highly likely that john picked up the milk, or Brian is a swan.
hypothesis_assertion: John picked up the milk, or Brian is a swan.