assertion  retraction  graph  subject    predicate        object    datatype    annotation
1          0           graph  DOID:6425  rdfs:subClassOf  DOID:530  _IRI        
1          0           graph  DOID:530   oio:id           DOID:530  xsd:string  
1          0           graph  DOID:9423  rdfs:subClassOf  DOID:530  _IRI        
1          0           graph  DOID:2173  rdfs:subClassOf  DOID:530  _IRI