assertion  retraction  graph  subject     predicate        object     datatype    annotation
1          0           graph  DOID:3128   oio:id           DOID:3128  xsd:string  
1          0           graph  DOID:4551   rdfs:subClassOf  DOID:3128  _IRI        
1          0           graph  DOID:14110  rdfs:subClassOf  DOID:3128  _IRI