Bob is not blue. Bob is round. Bob is smart. Dave is blue. Fiona is big. Gary is big. Gary is not nice. Gary is not quiet. Gary is rough. Gary is smart. If Gary is rough and Gary is quiet then Gary is nice. If something is not big then it is not quiet. If Fiona is not blue then Fiona is round. If something is not smart then it is rough. If something is rough and not big then it is not quiet. If Bob is quiet then Bob is not rough. All quiet, smart things are not blue. If Fiona is nice and Fiona is rough then Fiona is quiet.
Bob is not rough.