Sat, 23 Oct 2010 12:51:38 +0000 add some proofs about the other direction
wu [Sat, 23 Oct 2010 12:51:38 +0000] rev 12
add some proofs about the other direction 1: the NULL case 2: the EMPTY case 3: the atomic CHAR c case
Fri, 22 Oct 2010 19:43:56 +0000 deleted two unnecessary lemmas
urbanc [Fri, 22 Oct 2010 19:43:56 +0000] rev 11
deleted two unnecessary lemmas
(0) -10 -2 +2 +10 +30 +100 +300 tip