How many {activating neurotransmitter} are to/by {γ-aminobutyric acid} ?
y-aminobutyric acid has activated neurotransmitters, how many?
how many activated neurotransmitters are in y-aminobutyric acid?
SELECT ( COUNT ( ?s ) AS ?a ) { ?s property:activating_neurotransmitter resource:γ-aminobutyric_acid }
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/P928> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q210021 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P928 wd:Q210021 }
4