Wed, 31 Aug 2011 07:51:55 -0700 convert to Isar-style proof
huffman [Wed, 31 Aug 2011 07:51:55 -0700] rev 44627
convert to Isar-style proof
(0) -30000 -10000 -3000 -1000 -300 -100 -30 -10 -1 +1 +10 +30 +100 +300 +1000 +3000 +10000 +30000 tip