There are several places where nesting of queries might be useful - in the CONSTRUCT clause is one place which is convenient syntax
Another is in the pattern itself: by popular demand I added a limited
form:
SELECT ?a
FROM <mybooks.rdf>
{
?b dc:title ?title .
SERVICE <http://sparql.org/books>
{ ?s dc:title ?title . ?s dc:creator ?a }
http://jena.sourceforge.net/ARQ/service.html
With aggregation and GROUP BY, nested SELECT queries in-pattern make a
lot of sense.
Also EXISTS in FILTERs.
Andy
