context: It is highly likely that Greg is gray. It is impossible that Brian is a swan. It is improbable that Julius is white.
hypothesis: It is improbable that either Brian is a swan, or Julius is white.
valid_hypothesis: It is improbable that either Brian is a swan, or Julius is white.
invalid_hypothesis: There is a very good chance that either Brian is a swan, or Julius is white.
hypothesis_assertion: Either Brian is a swan, or Julius is white.