It is highly unlikely that Brian is white. There is almost no chance that Bernhard is white. It is highly unlikely that Julius is a frog. It is certain that if Julius is a frog, and Bernhard is white, then Greg is gray. It is probably not the case that if Bernhard is white, or Julius is a frog, then John got the milk. We believe that if Brian is white, and Bernhard is white, then Mary went to the office.
It is likely that brian is white, and Bernhard is white.
This example is invalid.