how does select/project work with extra variables?

Bob write:

--------
First, I am assuming that the
following query returns no bindings:

SELECT ?x ?y
  WHERE  { ?book dc10:title ?x }
 
I shouldn't since it doesn't refer to OPTIONAL or UNION within the query, and the
spec cites those as prerequisites for allowing unbound values.
--------
 --
http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2005Mar/0048.html

but I don't see it that way... my reading of 
  http://www.w3.org/2001/sw/DataAccess/rq23/#select
is that SELECT (i.e. projection) doesn't cause solutions
to get rejected. The ?y is just noise.


Would somebody please add this as a test case? EricP?

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
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