Dave is blue. Dave is green. Dave is kind. Dave is quiet. Dave is rough. Dave is round. Dave is young. Erin is green. Erin is kind. Erin is rough. Erin is young. Fiona is blue. Fiona is quiet. Fiona is rough. Fiona is round. Fiona is young. Blue, young things are rough. If Erin is round then Erin is quiet. All round things are blue. If something is round and young then it is green. All blue, round things are young. Quiet things are green. If Dave is young then Dave is quiet. All quiet things are round.
Erin is not blue.