NEWS

--- a/NEWS	Sun Nov 15 16:37:03 2015 +0100
+++ b/NEWS	Mon Nov 16 12:37:46 2015 +0100
@@ -546,6 +546,8 @@
 expose low-level facts of the internal construction only if the option
 "function_defs" is enabled. Rare INCOMPATIBILITY.
 
+* Data_Structures: new and growing session of standard data structures.
+
 * Imperative_HOL: obsolete theory Legacy_Mrec has been removed.
 
 * Library/Omega_Words_Fun: Infinite words modeled as functions nat =>