How many {discoverer or inventor} are to/by {Andrey Kolmogorov} ?
Andrey Kolmogorov discovered/invented how many things?
How many things did Andrey Kolmogorov discover or invent?
SELECT ( COUNT ( ?k ) AS ?f ) { ?k property:discoverer_or_inventor resource:Andrey_Kolmogorov }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P61> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q153224 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P61 wd:Q153224 }
8