context: It is almost certain that Brian is a swan. Chances are about even that Mary went to the kitchen. It is impossible that Lily is gray. It is improbable that if Lily is gray, or Mary went to the kitchen, then Julius is a frog. It is highly unlikely that if Lily is gray, or Brian is a swan, then Greg is green. It is impossible that if Lily is gray, and Brian is a swan, then Yann is thirsty.
hypothesis: It is highly unlikely that greg is green, and Brian is a swan.
valid_hypothesis: It is highly unlikely that greg is green, and Brian is a swan.
invalid_hypothesis: Chances are about even that greg is green, and Brian is a swan.
hypothesis_assertion: Greg is green, and Brian is a swan.