--- a/IOA/example/Packet.thy	Wed Nov 09 19:50:36 1994 +0100
+++ b/IOA/example/Packet.thy	Wed Nov 09 19:51:09 1994 +0100
@@ -1,3 +1,11 @@
+(*  Title:      HOL/IOA/example/Packet.thy
+    ID:         $Id$
+    Author:     Tobias Nipkow & Konrad Slind
+    Copyright   1994  TU Muenchen
+
+Packets
+*)
+
 Packet = Arith +
 
 types
@@ -9,10 +17,9 @@
   hdr  :: "'msg packet => bool"
   msg :: "'msg packet => 'msg"
 
-rules
+defs
 
   hdr_def "hdr == fst"
-
   msg_def "msg == snd"
 
 end