assertion  retraction  graph  subject          predicate        object                     datatype    annotation
1          0           graph  obo:CHEBI_51143  rdfs:label       nitrogen molecular entity  xsd:string  
1          0           graph  obo:CHEBI_51143  oio:id           CHEBI:51143                xsd:string  
1          0           graph  obo:CHEBI_51143  rdfs:subClassOf  obo:CHEBI_33302            _IRI        
1          0           graph  obo:CHEBI_51143  rdf:type         owl:Class                  _IRI