context: It is likely that Bernhard is green. It is improbable that Brian is a swan. We believe that Julius is white.
hypothesis: It is impossible that either Brian is a swan, or Julius is white.
valid_hypothesis: It is probably the case that either Brian is a swan, or Julius is white.
invalid_hypothesis: It is impossible that either Brian is a swan, or Julius is white.
hypothesis_assertion: Either Brian is a swan, or Julius is white.