What is {chairperson} of {International Mathematical Union} that is {end time} is {1978-0-0} ?
In 1978, who was the chairperson of the International Mathematical Union?
What is the { chairperson } of the { International Mathematical Union } that is { end time } { 1978.0 - 0 }?
SELECT ?o WHERE { ?f property:chairperson ?o . resource:International_Mathematical_Union property:chairperson ?f . ?f property:end_time ?n . FILTER ( CONTAINS ( YEAR ( ?n ) , '1978' ) ) }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q828490> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P488> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P582> <1978-0-0>
} 

SELECT ?obj WHERE { wd:Q828490 p:P488 ?s . ?s ps:P488 ?obj . ?s pq:P582 ?x filter(contains(YEAR(?x),'1978')) }