Dave is not blue. Dave is green. Dave is not kind. Dave is red. Dave is rough. Dave is smart. Dave is white. Harry is blue. Harry is green. Harry is kind. Harry is red. Harry is rough. Harry is smart. Harry is white. If Dave is green then Dave is white. White things are red. If something is white and not smart then it is green. If something is blue and green then it is red. If something is not smart then it is blue. If Harry is not red and Harry is not kind then Harry is green.
Dave is not white.