context: It is impossible that Bernhard is a lion. There is almost no chance that Mary put down the milk. Chances are about even that Sandra left the apple. There is almost no chance that if Mary put down the milk, and Bernhard is a lion, then Brian is a swan. It is probably not the case that if Bernhard is a lion, and Mary put down the milk, then Greg is a frog. We believe that if Bernhard is a lion, or Mary put down the milk, then Yann is tired.
hypothesis: It is impossible that either Brian is a swan, or Bernhard is a lion.
valid_hypothesis: It is impossible that either Brian is a swan, or Bernhard is a lion.
invalid_hypothesis: It is likely that either Brian is a swan, or Bernhard is a lion.
hypothesis_assertion: Either Brian is a swan, or Bernhard is a lion.