Nabokov answered : `` I often think there should exist a special typographical sign for a smile -- some sort of concave mark , a supine round bracket , which I would now like to trace in reply to your question . '' Nabokov answered : `` I often think there should exist a special typographical sign for a smile â '' some sort of concave mark , a supine round bracket , which I would now like to trace in reply to your question . ''