It is improbable that Mary moved to the office. It is highly unlikely that Daniel got the milk. It is improbable that Bernhard is a rhino. Chances are slight that if Bernhard is a rhino, and Daniel got the milk, then Brian is green. It is unlikely that if Daniel got the milk, or Bernhard is a rhino, then Greg is gray. It is unlikely that if either Mary moved to the office, or Daniel got the milk, then Sandra left the football.
It is almost certain that bernhard is a rhino, and Brian is green.
This example is valid.