assertion  retraction  graph  subject    predicate        object     datatype    annotation
1          0           graph  DOID:1618  oio:id           DOID:1618  xsd:string  
1          0           graph  DOID:2639  rdfs:subClassOf  DOID:1618  _IRI        
1          0           graph  DOID:2656  rdfs:subClassOf  DOID:1618  _IRI        
1          0           graph  DOID:7223  rdfs:subClassOf  DOID:1618  _IRI