query: #title: Ordinal qualifier would generally be unique within season
  # Complex constraint from [[Property talk:P4908]]
  # define exceptions when needed
  SELECT ?item ?itemLabel ?season ?seasonLabel ?ordinal
  WITH
  {  SELECT ?season ?ordinal (COUNT(DISTINCT ?ep) as ?ct)
    {
  	?ep p:P4908 [ ps:P4908 ?season ; pq:P1545 ?ordinal ] ; wdt:P31 wd:Q21191270
    }
    GROUP BY ?season ?ordinal 
    HAVING ( ?ct > 1)
  } as %find
  WHERE
  {
    INCLUDE %find 
    ?item  p:P4908 [ ps:P4908 ?season  ; pq:P1545 ?ordinal ]         
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en,it". }
  }
  ORDER BY ?season xsd:integer(?ordinal)