What is {developer} of {has outcome} of {protoplanetary disk} ?
who founded the protoplanetary disk?
How is the founder of the protoplanetary disk?
SELECT ?x WHERE { ?a property:discoverer_or_inventor ?x . resource:protoplanetary_disk property:has_effect ?a }
SELECT ?answer WHERE { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q505781> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1542>. ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?X . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?X. ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P61> . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?answer . }
SELECT ?answer WHERE { wd:Q505781 wdt:P1542 ?X . ?X wdt:P61 ?answer}
Thomas Chrowder Chamberlin Viktor Safronov