Dave is furry. Dave is green. Dave is nice. Dave is not quiet. Dave is rough. Dave is round. Dave is not young. Fiona is furry. Fiona is green. Fiona is not nice. Fiona is quiet. Fiona is rough. Fiona is round. Fiona is young. If Fiona is not young then Fiona is furry. If something is not nice and not rough then it is not round. If something is round and not quiet then it is furry.
Fiona is not young.