context: It is probable that Greg is a swan. It is impossible that Mary got the milk. It is probable that Bernhard is a lion. Chances are slight that if Mary got the milk, and Bernhard is a lion, then Brian is yellow. It is probable that if either Mary got the milk, or Bernhard is a lion, then Bill went to the hallway. We doubt that if either Bernhard is a lion, or Greg is a swan, then Lily is a lion.
hypothesis: It is certain that either Greg is a swan, or Bernhard is a lion.
valid_hypothesis: Chances are about even that either Greg is a swan, or Bernhard is a lion.
invalid_hypothesis: It is certain that either Greg is a swan, or Bernhard is a lion.
hypothesis_assertion: Either Greg is a swan, or Bernhard is a lion.