--- a/NEWS Fri Jun 11 16:52:17 2010 +0200
+++ b/NEWS Mon Jun 14 15:10:36 2010 +0200
@@ -25,6 +25,9 @@
INCOMPATIBILITY.
+* Removed simplifier congruence rule of "prod_case", as has for long
+been the case with "split".
+
New in Isabelle2009-2 (June 2010)
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