How many {discoverer or inventor} are for {mathematical induction} ?
What is the number of discoverers of mathematical induction?
How many discoverers are there of mathematical induction?
SELECT ( COUNT ( ?r ) AS ?a ) { resource:mathematical_induction property:discoverer_or_inventor ?r }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q178377> .
?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> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q178377 wdt:P61 ?obj }
7