--- /dev/null
+<?xml encoding="ISO-8859-1"?>
+
+<!-- Copyright (C) 2000, HELM Team -->
+<!-- -->
+<!-- This file is part of HELM, an Hypertextual, Electronic -->
+<!-- Library of Mathematics, developed at the Computer Science -->
+<!-- Department, University of Bologna, Italy. -->
+<!-- -->
+<!-- HELM is free software; you can redistribute it and/or -->
+<!-- modify it under the terms of the GNU General Public License -->
+<!-- as published by the Free Software Foundation; either version 2 -->
+<!-- of the License, or (at your option) any later version. -->
+<!-- -->
+<!-- HELM is distributed in the hope that it will be useful, -->
+<!-- but WITHOUT ANY WARRANTY; without even the implied warranty of -->
+<!-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -->
+<!-- GNU General Public License for more details. -->
+<!-- -->
+<!-- You should have received a copy of the GNU General Public License -->
+<!-- along with HELM; if not, write to the Free Software -->
+<!-- Foundation, Inc., 59 Temple Place - Suite 330, Boston, -->
+<!-- MA 02111-1307, USA. -->
+<!-- -->
+<!-- For details, see the HELM World-Wide-Web page, -->
+<!-- http://cs.unibo.it/helm/. -->
+
+<!--*****************************************************************-->
+<!-- DTD FOR ANNOTATED OBJECTS: -->
+<!-- First draft: June 2000, Claudio Sacerdoti Coen -->
+<!--*****************************************************************-->
+
+<!ENTITY % annotation '(#PCDATA|node|attribute)*'>
+
+<!ELEMENT Annotations (Annotation)*>
+<!ATTLIST Annotations
+ of CDATA #REQUIRED>
+
+<!ELEMENT Annotation %annotation;>
+<!ATTLIST Annotation
+ of CDATA #REQUIRED>
+
+<!-- Annotations: -->
+
+<!ELEMENT attribute EMPTY>
+<!ATTLIST attribute
+ name NMTOKEN #REQUIRED
+ id NMTOKEN #REQUIRED
+ child NMTOKEN #IMPLIED
+ grandchild NMTOKEN #IMPLIED>
+
+<!ELEMENT node EMPTY>
+<!ATTLIST node
+ id NMTOKEN #REQUIRED>