@prefix rdfs:	<http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos:	<http://www.w3.org/2004/02/skos/core#> .
@prefix virtrdf:	<http://www.openlinksw.com/schemas/virtrdf#> .
skos:prefLabel	rdfs:subPropertyOf	virtrdf:label .