Fri, 05 Dec 2008 17:26:16 -0800 add lemma le_nat_number_of
huffman [Fri, 05 Dec 2008 17:26:16 -0800] rev 29010
add lemma le_nat_number_of
(0) -10000 -3000 -1000 -300 -100 -30 -10 -1 +1 +10 +30 +100 +300 +1000 +3000 +10000 +30000 tip