It is highly unlikely that Mary took the apple. We doubt that Greg is a lion. It is certain that Bill discarded the milk.
It is probably not the case that either Greg is a lion, or Mary took the apple.
It is probably not the case that either Greg is a lion, or Mary took the apple.
It is probably the case that either Greg is a lion, or Mary took the apple.
Either Greg is a lion, or Mary took the apple.