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Re: defn binding wordy

From: Dan Connolly <connolly@w3.org>
Date: Fri, 03 Sep 2004 14:03:49 -0500
To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-Id: <1094238229.9133.668.camel@dirk>

On Fri, 2004-09-03 at 13:52, Dan Connolly wrote:
> In
> http://www.w3.org/2001/sw/DataAccess/rq23/#basicpatterns
> 
> first we have "A binding B is a subset of V x A"

Hmm... I'm struggling with the notation

  subst(T, b in B) is a triple pattern ...

I suggest you get rid of VAR() and VAL() and just exploit
the fact that bindings are functions ala...


First we define substitution for terms and then patterns:
subst(t, B) = if t in domain(B) then B(t) else t
subst(<s,p,o>, B) = <subst(s,B), subst(p,B), subst(o,B)>

Then... regarding

"Triple Pattern T matches graph G with binding B if subst(T, B) is a
ground triple and, as a triple, is entailed by G."

I'm not sure why you say "as a triple"; entailment is defined
as a relationship between graphs, not triples and graphs. I suggest,
rather:

  ... and, as a single-triple graph, is entailed by G.


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 3 September 2004 19:03:42 GMT

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