Bob is furry. Bob is not nice. Bob is not quiet. Bob is red. Bob is rough. Bob is smart. Bob is young. Dave is furry. Dave is nice. Dave is quiet. Dave is red. Dave is rough. Dave is smart. Dave is young. If something is furry and not smart then it is red. If something is red and not smart then it is furry. If something is nice and not rough then it is not young. If Dave is not rough then Dave is quiet. All furry, red things are young. If something is furry and not young then it is quiet. If something is smart and not furry then it is not rough. If something is not quiet then it is not nice.
Dave is not smart.