Bob is blue. Bob is rough. Dave is not white. Dave is young. Erin is quiet. Erin is rough. Erin is young. Harry is quiet. Harry is not red. Harry is not young. All quiet, young things are blue. All rough, red things are white. Red things are not white. If Dave is quiet and Dave is not young then Dave is red. Blue, rough things are not green. If something is green and young then it is blue.
Erin is not red.