assertion  retraction  graph  subject     predicate        object     datatype    annotation
1          0           graph  DOID:4515   rdfs:subClassOf  DOID:1781  _IRI        
1          0           graph  DOID:3963   rdfs:subClassOf  DOID:1781  _IRI        
1          0           graph  DOID:1781   oio:id           DOID:1781  xsd:string  
1          0           graph  DOID:10011  rdfs:subClassOf  DOID:1781  _IRI