Chances are about even that Greg is a swan. It is unlikely that Gertrude is a mouse. Chances are about even that John picked up the apple. We doubt that if John picked up the apple, and Gertrude is a mouse, then Lily is white. It is almost certain that if Gertrude is a mouse, and Greg is a swan, then Mary moved to the office. There is a better than even chance that if either John picked up the apple, or Gertrude is a mouse, then Julius is green.
There is a very good chance that either John picked up the apple, or Julius is green.
It is probably not the case that either John picked up the apple, or Julius is green.
There is a very good chance that either John picked up the apple, or Julius is green.
Either John picked up the apple, or Julius is green.