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Re: W3C RIF BLD Last Call (10 days left in comment period)

From: Story Henry <henry.story@bblfish.net>
Date: Tue, 9 Sep 2008 17:57:35 +0200
Cc: semantic-web@w3.org, public-lod@w3.org, www-rdf-rules@w3.org, www-rdf-logic@w3.org, public-rule-workshop-discuss@w3.org
Message-Id: <3BB6B877-E4E1-4AEA-BDFF-501C0B756BE6@bblfish.net>
To: Sandro Hawke <sandro@w3.org>

Just on first reading I find the syntax to be quite problematic. It  
clashes with other well known syntaxes namely Turtle, SPARQL and N3.

The two problems I see is that in those languages square brackets are  
used for blank nodes, and { } to delimit graphs.

As an example take the following
http://www.w3.org/TR/2008/WD-rif-rdf-owl-20080730/#RDF_Compatibility

[[
Forall ?x ?y ?z (?x[ex:uncleOf -> ?z] :-
        And(?x[ex:brotherOf -> ?y] ?y[ex:parentOf -> ?z]))
]]

If I were to write the above in SPARQL I think you meant to say

[[
PREFIX ex: <http://example.org/rif>

CONSTRUCT { ?x ex:uncleOf ?z }
WHERE {
      ?x ex:brotherOf ?y .
      ?y ex:parehtOf ?z .
}
]]

In N3 similarly

[[
{ ?x ex:brotherOf ?y .
   ?y ex:parehtOf ?z . } => { ?x ex:uncleOf ?z . }
]]

SPARQL is already widely deployed, and there are a lot of N3 rules out  
there, that are very useful guides for people working their way around  
the web. There is even more Turtle around, and it is a blessing that  
it is now being used, as RDF/XML though very nice in many ways, leads  
to a huge amount of confusion.

My feeling is that the current human readable syntax, not being  
aligned with SPARQL is going to create confusion unecessarily. It  
seems to be that an attempt should be made to get something that fits  
better with SPARQL and N3 intuitions, so as to make the learning curve  
as light as possible for people who are new to this world.

	Henry

On 9 Sep 2008, at 16:51, Sandro Hawke wrote:

>
>
> The W3C specifications for logic rules and for using rules with RDF  
> and
> OWL are in their "Last Call" public comment period.  This is the time
> for people to read them and tell us about anything that doesn't seem
> right.  After this, if you don't like something in the spec, it will  
> be
> increasingly hard to get it changed.  We would like comments by
> September 19 in order to consider them for our next set of revisions.
>
> For more details, see this e-mail I sent August 1st:
> http://lists.w3.org/Archives/Public/semantic-web/2008Aug/0002.html
>
> Thanks!
>
>     -- Sandro
Received on Tuesday, 9 September 2008 15:58:28 GMT

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