Charlie is smart. Dave is green. Dave is nice. Dave is rough. Dave is white. Erin is green. Erin is nice. Erin is young. Harry is rough. Harry is smart. If Charlie is smart then Charlie is quiet. If Dave is rough then Dave is nice. If something is green and young then it is not rough. If Charlie is quiet then Charlie is young. All young things are white. If something is white and not nice then it is green. If something is not quiet then it is green.
Dave is young.