context: It is probable that Julius is a lion. We believe that Brian is a swan. It is improbable that John is in the office.
hypothesis: Chances are about even that brian is a swan, and Julius is a lion.
valid_hypothesis: Chances are about even that brian is a swan, and Julius is a lion.
invalid_hypothesis: There is almost no chance that brian is a swan, and Julius is a lion.
hypothesis_assertion: Brian is a swan, and Julius is a lion.