assertion  retraction  graph  subject          predicate        object                       datatype    annotation
1          0           graph  obo:CHEBI_33350  rdfs:label       chromium group element atom  xsd:string  
1          0           graph  obo:CHEBI_33350  oio:id           CHEBI:33350                  xsd:string  
1          0           graph  obo:CHEBI_33350  rdfs:subClassOf  obo:CHEBI_33561              _IRI        
1          0           graph  obo:CHEBI_33350  rdf:type         owl:Class                    _IRI