how many hadrons are in the family meson?
Value
5
class entity
physics.hadron m.04_rh
physics.hadron physics.particle_family
Hadron Meson
count none
physics.particle.family
Family
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX : <http://rdf.freebase.com/ns/> 
SELECT (COUNT(?x0) AS ?value) WHERE {
SELECT DISTINCT ?x0  WHERE { 
?x0 :type.object.type :physics.hadron . 
VALUES ?x1 { :m.04_rh } 
?x0 :physics.particle.family ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(COUNT (AND physics.hadron (JOIN physics.particle.family m.04_rh)))