--- /dev/null
+(* 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/.
+ *)
+
+(* AUTOR: Ferruccio Guidi <fguidi@cs.unibo.it>
+ *)
+
+type pg_map (* mathql path map for postgres *)
+
+type pg_tables
+
+type pg_alias
+
+val empty_map : unit -> pg_map * pg_alias
+
+val read_map : unit -> pg_map * pg_alias
+
+val get_tables : pg_map -> MathQL.path -> pg_tables
+
+val refine_tables : pg_tables -> pg_tables -> pg_tables
+
+val default_table : pg_tables -> string
+
+val get_field : pg_map -> MathQL.path -> string -> string
+
+val resolve : pg_alias -> string -> string