context: It is probable that Emily is a sheep. Chances are about even that Lily is a swan. It is impossible that Brian is white.
hypothesis: It is impossible that brian is white, and Lily is a swan.
valid_hypothesis: It is impossible that brian is white, and Lily is a swan.
invalid_hypothesis: It is probable that brian is white, and Lily is a swan.
hypothesis_assertion: Brian is white, and Lily is a swan.