context: We believe that Mary went to the hallway. It is likely that Greg is a rhino. Chances are slight that Gertrude is a mouse. It is almost certain that if Greg is a rhino, and Mary went to the hallway, then Brian is white. It is almost certain that if either Mary went to the hallway, or Gertrude is a mouse, then Sandra left the milk. We doubt that if Mary went to the hallway, or Greg is a rhino, then Lily is a frog.
hypothesis: Chances are about even that greg is a rhino, and Brian is white.
valid_hypothesis: Chances are about even that greg is a rhino, and Brian is white.
invalid_hypothesis: It is highly unlikely that greg is a rhino, and Brian is white.
hypothesis_assertion: Greg is a rhino, and Brian is white.