context: Chances are about even that Yann is thirsty. It is highly unlikely that Sandra grabbed the milk. It is improbable that John left the apple. It is highly likely that if either John left the apple, or Sandra grabbed the milk, then Brian is gray. There is little chance that if Sandra grabbed the milk, or Yann is thirsty, then Fred went to the hallway. It is unlikely that if Sandra grabbed the milk, or John left the apple, then Greg is a swan.
hypothesis: There is little chance that greg is a swan, or Fred went to the hallway.
valid_hypothesis: There is little chance that greg is a swan, or Fred went to the hallway.
invalid_hypothesis: There is a better than even chance that greg is a swan, or Fred went to the hallway.
hypothesis_assertion: Greg is a swan, or Fred went to the hallway.