<http://www.w3.org/2004/02/skos/core#prefLabel> <http://www.w3.org/2000/01/rdf-schema#subPropertyOf> <http://www.openlinksw.com/schemas/virtrdf#label> . <http://www.w3.org/2004/02/skos/core#prefLabel> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#AnnotationProperty> .