- msg_output_string msg ("<rdf:RDF xml:lang=\"en\"\n xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"\n xmlns:rdfs=\"http://www.w3.org/2000/01/rdf-schema#\"\n xmlns:dc=\"http://purl.org/metadata/dublin_core#\"\n xmlns:dcq=\"http://purl.org/metadata/dublin_core_qualifiers#\"\n xmlns:h=\"http:/www.cs.unibo.it/helm/schemas/schema-h.rdf#\"\n xmlns:hth=\"http://www.cs.unibo.it/helm/schemas/schema-hth.rdf#\">\n")
+ msg_output_string msg ("<rdf:RDF xml:lang=\"en\"\n xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"\n xmlns:rdfs=\"http://www.w3.org/2000/01/rdf-schema#\"\n xmlns:dc=\"http://purl.org/metadata/dublin_core#\"\n xmlns:dcq=\"http://purl.org/metadata/dublin_core_qualifiers#\"\n xmlns:h=\"http:/www.cs.unibo.it/helm/schemas/schema-h.rdf#\"\n xmlns:hth=\"http://www.cs.unibo.it/helm/schemas/schema-hth.rdf#\">\n") ;
+ msg_output_string msg " <h:DirectoryOfObjects>"