context: Chances are slight that Bernhard is a swan. It is impossible that Brian is a lion. There is almost no chance that Lily is a frog. It is unlikely that if Brian is a lion, and Lily is a frog, then Mary dropped the milk. It is improbable that if either Lily is a frog, or Brian is a lion, then Julius is gray. It is unlikely that if Brian is a lion, and Lily is a frog, then Jeff went to the kitchen.
hypothesis: It is impossible that lily is a frog, and Brian is a lion.
valid_hypothesis: It is impossible that lily is a frog, and Brian is a lion.
invalid_hypothesis: It is probably the case that lily is a frog, and Brian is a lion.
hypothesis_assertion: Lily is a frog, and Brian is a lion.