rdf-mt/commit

Added graph_properties.pl

diff --git a/lib/rdf_mt/graph_properties.pl b/lib/rdf_mt/graph_properties.pl
new file mode 100644
index 0000000..cfd698a
--- /dev/null
+++ b/lib/rdf_mt/graph_properties.pl
@@ -0,0 +1,42 @@
+/*  Part of ClioPatria SeRQL and SPARQL server
+
+    Author:        Jan Wielemaker
+    E-mail:        J.Wielemaker@cs.vu.nl
+    WWW:           http://www.swi-prolog.org
+    Copyright (C): 2013, University of Amsterdam,
+		   VU University Amsterdam
+
+    This program 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.
+
+    This program 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 this library; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    As a special exception, if you link this library with other files,
+    compiled with a Free Software compiler, to produce an executable, this
+    library does not by itself cause the resulting executable to be covered
+    by the GNU General Public License. This exception does not however
+    invalidate any other reasons why the executable file might be covered by
+    the GNU General Public License.
+*/
+
+:- module(graph_properties,
+	  [ empty_graph/1
+	  ]).
+
+/** <module> Predicates that prove properties about RDF graphs
+*/
+
+%%	empty_graph(?Graph)
+%
+%	True when Graph is the empty graph
+
+empty_graph([]).