assertion  retraction  graph  subject          predicate        object           datatype    annotation
1          0           graph  obo:CHEBI_36606  rdfs:label       acid anhydride   xsd:string  
1          0           graph  obo:CHEBI_36606  oio:id           CHEBI:36606      xsd:string  
1          0           graph  obo:CHEBI_36606  rdfs:subClassOf  obo:CHEBI_50860  _IRI        
1          0           graph  obo:CHEBI_36606  rdf:type         owl:Class        _IRI