conversion:date_pattern

PREFIX rdfs:       <http://www.w3.org/2000/01/rdf-schema#>
PREFIX xsd:        <http://www.w3.org/2001/XMLSchema#>
PREFIX conversion: <http://purl.org/twc/vocab/conversion/>

SELECT count(distinct ?enhancement) as ?count
WHERE {
  GRAPH <http://purl.org/twc/vocab/conversion/ConversionProcess> {
    ?dataset a void:Dataset;
      conversion:conversion_process [
        conversion:enhance ?enhancement
      ]
    .
    ?enhancement conversion:date_pattern ?pattern .
  }
}