Bob is nice. Bob is red. Bob is rough. Dave is cold. Dave is nice. Dave is red. Dave is white. Dave is not young. Harry is nice. Harry is young. Rough people are quiet. If Bob is quiet and Bob is not rough then Bob is not white. If Dave is red and Dave is not young then Dave is quiet. If someone is cold and not red then they are white. All red people are quiet. If Harry is red then Harry is rough. If Dave is not quiet then Dave is cold. If someone is not cold then they are white.
Dave is not white.