prefix rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix foaf: <http://xmlns.com/foaf/0.1/>
prefix pkg:  <http://docs.oasis-open.org/opendocument/meta/package/common#>

select ?s ?p ?o
where {
 ?s pkg:idref ?xmlid .
 ?s ?p ?o .
 filter( str(?xmlid) = str("rdfid4") )
}