context: Chances are about even that Brian is a lion. It is highly unlikely that John picked up the milk. We doubt that Lily is a rhino.
hypothesis: It is likely that john picked up the milk, or Lily is a rhino.
valid_hypothesis: It is probably not the case that john picked up the milk, or Lily is a rhino.
invalid_hypothesis: It is likely that john picked up the milk, or Lily is a rhino.
hypothesis_assertion: John picked up the milk, or Lily is a rhino.