Bob is big. Bob is blue. Bob is green. Bob is rough. Bob is round. Bob is smart. Bob is white. Dave is big. Dave is blue. Dave is green. Dave is rough. Dave is round. Dave is smart. Dave is white. If something is green then it is smart. If something is smart and green then it is rough. If Bob is rough and Bob is white then Bob is green. If something is smart then it is white. White things are rough. All rough things are big. All big things are green. All big things are blue.
Bob is not green.