Dave is young. Dave is round. Dave is rough. Dave is kind. Dave is big. Eric is nice. Eric is green. Eric is big. Fred is cold. Fred is blue. Fred is big. Harry is cold. If someone is red and rough then they are blue. If someone is red and green and kind then they are round. If someone is young and big and round then they are red. If someone is cold and red then they are green. If someone is blue and red and young then they are rough. If someone is blue then they are green. If someone is kind and nice then they are young.
Dave is not blue.