- From: Jos De_Roo <jos.deroo@agfa.com>
- Date: Sat, 25 Sep 2004 20:55:43 +0200
- To: ""Seaborne@smtp2.agfa.be, Andy" <andy.seaborne" <andy.seaborne@hp.com>, "Eric Prud'hommeaux" <eric@w3.org>
- Cc: public-rdf-dawg@w3.org
Andy,
Eric,
I made 2 test cases
1/
data: http://eulersharp.sourceforge.net/2004/04test/D1.n3
query: http://eulersharp.sourceforge.net/2004/04test/D1Q.n3
gives: http://eulersharp.sourceforge.net/2004/04test/D1E.n3
which is an empty answer
because the bnodes in D2.n3 could be some different things
2/
data: http://eulersharp.sourceforge.net/2004/04test/D2.n3
query: http://eulersharp.sourceforge.net/2004/04test/D2Q.n3
gives: http://eulersharp.sourceforge.net/2004/04test/D1E.n3
which is 2 answers
because the bnodes came from the same graph D2.n3
and so they unify
at least that is my current understanding about relabeling
bnodes and unification :)
jos
--
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
"Seaborne, Andy" <andy.seaborne@hp.com>
25/09/2004 17:01
To: Jos De_Roo/AMDUS/MOR/Agfa-NV/BE/BAYER@AGFA, "Eric Prud'hommeaux"
<eric@w3.org>
cc:
Subject: SOURCE in N3QL
Jos,
I tried to explain this to Eric in an email and I have a question:
> well, I thought that
>
> SELECT ?x ?y ?n
> WHERE
> (?x foaf:knows ?y)
> SOURCE <D2.n3> (?x foaf:age ?n)
> ...
>
> nicely maps to
>
> []
> q:select {(?x ?y ?n) a q:Answer};
> q:where {?x foaf:knows ?y.
> <D2.n3>.log:semantics log:includes {?x foaf:age ?n}}.
> ...
?x is a bNode.
My thought:
----
The query assumes that <D2.n3> has the same bNode as the outer context "?x
foaf:knows ?y" so there may be there is an assumption that the global
graph is the RDF merge of the named components.
----
Is my thought right or wrong or misguided?
Which ever, this is beginning to give a possible theoretical foundation
for SOURCE.
Andy
Received on Saturday, 25 September 2004 18:56:29 UTC