Bob is quiet. Dave is smart. Dave is young. Erin is blue. Erin is furry. Erin is quiet. Erin is round. Erin is smart. Harry is blue. Harry is furry. Harry is quiet. Harry is round. If Dave is nice then Dave is blue. If Dave is furry and Dave is smart then Dave is blue. If someone is round and young then they are nice. All round people are blue. If someone is blue then they are young. If someone is quiet and smart then they are young. Young, quiet people are round. Quiet people are furry. Furry people are round.
Erin is not nice.