What is {child} of {Agamemnon} that is {mother} is {Clytemnestra} ?
Who is the kid of Agamemnon and Clytemnestra's mother?
Who is the child of Agamemnon and the mother of Clytemnestra?
SELECT ?p WHERE { ?g property:child ?p . ?g property:mother resource:Clytemnestra . resource:Agamemnon property:child ?g }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q128176> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P40> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P25> <http://wikidata.dbpedia.org/resource/Q131157>
} 

SELECT ?obj WHERE { wd:Q128176 p:P40 ?s . ?s ps:P40 ?obj . ?s pq:P25 wd:Q131157 }