PREFIX dance: <https://w3id.org/rete/dance#>
SELECT ?metric ?n WHERE {
{ SELECT ("dancers" AS ?metric) (COUNT(?d) AS ?n) WHERE { ?d a dance:Dancer } }
UNION { SELECT ("pairs" AS ?metric) (COUNT(?p) AS ?n) WHERE { ?p a dance:Pair } }
UNION { SELECT ("performances" AS ?metric) (COUNT(?pf) AS ?n) WHERE { ?pf a dance:Performance } }
UNION { SELECT ("move segments" AS ?metric) (COUNT(?s) AS ?n) WHERE { ?x dance:hasSegment ?s } }
}