context: Chances are slight that Brian is a rhino. Chances are slight that Julius is a swan. It is improbable that Greg is gray. There is a better than even chance that if Julius is a swan, or Brian is a rhino, then John picked up the milk. There is little chance that if either Greg is gray, or Brian is a rhino, then Bernhard is a lion. Chances are about even that if Greg is gray, or Brian is a rhino, then Mary went to the kitchen.
hypothesis: It is highly unlikely that john picked up the milk, and Julius is a swan.
valid_hypothesis: It is highly unlikely that john picked up the milk, and Julius is a swan.
invalid_hypothesis: There is a very good chance that john picked up the milk, and Julius is a swan.
hypothesis_assertion: John picked up the milk, and Julius is a swan.