added simpset thy_data;

--- a/src/FOL/IFOL.thy	Mon Nov 03 12:24:13 1997 +0100
+++ b/src/FOL/IFOL.thy	Mon Nov 03 12:26:45 1997 +0100
@@ -112,3 +112,6 @@
   iff_reflection  "(P<->Q) ==> (P==Q)"
 
 end
+
+
+ML val thy_data = [Simplifier.simpset_thy_data];