Not quite crossing the pons asinorum of construct

[Benson Margulies]

Goal here: (a) all triples with a subject which has a
'hasNormalizedText' of "Kerr" and also (b) all triples with a subject
which 'is owl:sameAs' one of the subjects from (a). Inference is not
turned on, so I have to (?) do this myself. I seem to be stuck on how
to get the rest of the triples for the subjects that pass the sameAs
test.

PREFIX rex:   <http://www.basistech.com/ontologies/2010/6/rex.owl#>
PREFIX owl:   <http://www.w3.org/2002/07/owl#>
PREFIX x-arq: <urn:x-arq:>

CONSTRUCT {
# all tuples with the selected entity as a subject
?entity ?pred ?val .
?corefEntity owl:sameAs ?entity .
}
WHERE
{
        GRAPH x-arq:UnionGraph {
           ?entity rex:hasNormalizedText "Kerr" .
           OPTIONAL { ?entity ?pred ?val }
           OPTIONAL { ?corefEntity owl:sameAs ?entity }
        }
}