2011-08-11 some typos
urbanc [Thu, 11 Aug 2011 23:42:06 +0000] rev 194
some typos
2011-08-11 finished section about derivatives and closure properties
urbanc [Thu, 11 Aug 2011 23:11:39 +0000] rev 193
finished section about derivatives and closure properties
(0) -100 -30 -10 -2 +2 +10 +30 +100 tip