RE: Scope

>Message-ID: <3BFAD963.74FC18FA@informatik.uni-kl.de>
>Date: Tue, 20 Nov 2001 23:29:55 +0100
>From: Harold Boley <boley@informatik.uni-kl.de>
>To: Andy_Seaborne@hplb.hpl.hp.com
>CC: www-rdf-rules@w3.org
>Subject: RE: Scope
>
>Hi Andy,
>
>> I'm not up to speed on RuleML but it does seem like a starting point to
>> consider.   Would someone like to comment here?  How would it describe
>> getting back a set of results?
>
>An XML-RDF standard for inference *results* is not part of the current
RuleML 0.8
>proposal. But like in Bruce Spencer's recent j-DREW or Richerd Fikes'
DAML+OIL query
>proposal, inference results could be represented as instantiated query
atoms in 0.8.

Seems like a worthwhile direction to try out, so...

I put together a simple example of using RuleML to specify a query against
RDF and to return results. You can check it out at
http://209.198.94.130/ruleml/query.asp. You specify your query as an
implication and the url of the rdf file you want to query. The results are
returned as RuleML <fact>s. I think I got the RuleML right, but please let
me know otherwise.

A few questions that came up in the process:

- how should type be handled? i.e. how should the uri "www.w3.org" be
distinguished from the literal "www.w3.org"? an attribute could be added to
<ind>? or just use syntax convention with text values -- [www.w3.org] vs.
'www.w3.org'?

- it would be nice to be able to use namespaces in <ind> values. I guess
there's no way with the current syntax to get them for free - i.e. get the
parser to expand them. Absent that, a convention such as passing along alias
information as additional <fact>s might be handy.

Overall, seems to work pretty well. It doesn't seem like too much of a
force-fit or misuse of the language and results aren't too verbose.

--Geoff

Received on Tuesday, 20 November 2001 22:57:37 UTC