(*
- * Copyright (C) 2000, HELM Team.
+ * Copyright (C) 2003:
+ * Stefano Zacchiroli <zack@cs.unibo.it>
+ * for the HELM Team http://helm.cs.unibo.it/
*
* This file is part of HELM, an Hypertextual, Electronic
* Library of Mathematics, developed at the Computer Science
* MA 02111-1307, USA.
*
* For details, see the HELM World-Wide-Web page,
- * http://cs.unibo.it/helm/.
+ * http://helm.cs.unibo.it/
*)
class threadSafe: