what is the {start time} for {Arthur Cayley} has {member of} as {Royal Astronomical Society} ?
Who was the member of Royal Astronomical Society at the time of Arthur Cayley?
What time does Arthur Cayley, member of the Royal Astronomical Society start?
SELECT ?o WHERE { ?d property:member_of resource:Royal_Astronomical_Society . ?d property:start_time ?o . resource:Arthur_Cayley property:member_of ?d }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q159430> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P463> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q753299> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q159430 p:P463 ?s . ?s ps:P463 wd:Q753299 . ?s pq:P580 ?value}