context: Chances are about even that Julius is a lion. Chances are slight that Brian is a swan. It is highly likely that Fred is in the park.
hypothesis: It is impossible that brian is a swan, or Julius is a lion.
valid_hypothesis: There is a better than even chance that brian is a swan, or Julius is a lion.
invalid_hypothesis: It is impossible that brian is a swan, or Julius is a lion.
hypothesis_assertion: Brian is a swan, or Julius is a lion.