How many {guidance system} are to/by {Sonar} ?
Which is the guidance system of Sonar?
What is the guidance system of the {Sonar} ?
SELECT ( COUNT ( ?m ) AS ?k ) { ?m property:guidance_system resource:sonar }
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/P624> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q133220 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P624 wd:Q133220 }
4