Dave is blue. Dave is green. Dave is quiet. Dave is red. Dave is rough. Dave is round. Dave is smart. Fiona is blue. Fiona is green. Fiona is quiet. Fiona is round. Fiona is smart. If someone is green and quiet then they are red. If someone is rough and red then they are quiet. Green people are blue. All red people are rough. If someone is round and rough then they are red. All blue, smart people are red.
Dave is not smart.