Yet, Didn't you see another (my) answer? I am not angry but   
 I'm sorry that the another mathematical analys is deleted. It is really simple and most proper answer. You made deletion. But this wikipedia is free to rewrite. since there are people such as you, it is really sorry. I think I   
 or the other people repost the answer. I'm very tired now. 
 T.Maekawa 28 Jan 2006