@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . @prefix ns0: <http://www.daml.org/2003/01/periodictable/PeriodicTable#> . @prefix owl: <http://www.w3.org/2002/07/owl#> . ns0:period a owl:ObjectProperty . 
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix ns0: <http://www.daml.org/2003/01/periodictable/PeriodicTable#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .

ns0:period
    a owl:ObjectProperty .