Dave is not rough. Erin is furry. Fiona is smart. If Erin is not smart then Erin is young. If something is rough and smart then it is white. If Fiona is red and Fiona is white then Fiona is rough. If something is furry and not smart then it is white. If something is young and not smart then it is rough. All green things are not young.
Fiona is not white.