# No two qb:Observations in the same qb:DataSet may have the same value for all dimensions.
PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>
PREFIX skos:    <http://www.w3.org/2004/02/skos/core#>
PREFIX qb:      <http://purl.org/linked-data/cube#>
PREFIX xsd:     <http://www.w3.org/2001/XMLSchema#>
PREFIX owl:     <http://www.w3.org/2002/07/owl#>

ASK {
  FILTER( ?allEqual )
  {
    # For each pair of observations test if all the dimension values are the same
    SELECT (MIN(?equal) AS ?allEqual) WHERE {
      ?dataset qb:structure/qb:component/qb:componentProperty ?dim .
      ?dim a qb:DimensionProperty .
        ?obs1 qb:dataSet ?dataset .
        ?obs2 qb:dataSet ?dataset .
        FILTER (?obs1 != ?obs2)
        ?obs1 ?dim ?value1 .
        ?obs2 ?dim ?value2 .
        BIND( ?value1 = ?value2 AS ?equal)
    } GROUP BY ?obs1 ?obs2
  }
}