Question: When did Deke Slayton step down as Chief of the Astronaut Office?
Paraphrase: Give me the date that Deke Slayton stepped down as Chief of the Astronaut Office.
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q336810 p:P39 ?s . ?s ps:P39 wd:Q3667787 . ?s pq:P582 ?value}