Finding data errors with quotient summaries
This summary leads to an unexpected insight into the RDF graph: it contains an error, since the node w1 has itself as birthPlace and deathPlace. How can this be? Looking at the data we find e.g. the triples:
<http://dbpedia.org/resource/KunitomoIkkansai> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> .
<http://dbpedia.org/resource/KunitomoIkkansai> <http://dbpedia.org/ontology/birthPlace> <http://dbpedia.org/resource/KunitomoIkkansai> .
and the second one leads to the self-loop for a birthPlace property in the summary. (The error probably comes from the wrong disambiguation).