It is probably not the case that John discarded the milk. It is certain that Greg is a swan. It is likely that Bernhard is gray. We doubt that if Bernhard is gray, and John discarded the milk, then Mary moved to the office. There is a better than even chance that if Bernhard is gray, or John discarded the milk, then Lily is white. We doubt that if Bernhard is gray, and Greg is a swan, then Gertrude is a mouse.
It is certain that mary moved to the office, or John discarded the milk.
It is probably not the case that mary moved to the office, or John discarded the milk.
It is certain that mary moved to the office, or John discarded the milk.
Mary moved to the office, or John discarded the milk.