PREFIX ppeo: <http://purl.org/ppeo/PPEO.owl#>
PREFIX unlock: <http://m-unlock.nl/ontology/>
select ?library ?fwd ?rev (COUNT(?library) AS ?count)
where {
	?library a unlock:AmpliconLibraryAssay .
    ?assay unlock:library ?library .
    ?assay unlock:forwardBarcode ?fwd .
    ?assay unlock:reverseBarcode ?rev .
} GROUP BY ?library ?fwd ?rev
HAVING(?count > 1)