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Re: DRS guide

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Wed, 14 Jan 2004 21:46:16 -0500
Message-Id: <FD5908A3-4704-11D8-9237-0003936A0B26@isr.umd.edu>
Cc: public-sws-ig@w3.org, www-rdf-rules@w3.org
To: Drew McDermott <drew.mcdermott@yale.edu>

This thread started on public-sws-ig, but probably should move to 
www-rdf-rules.

I include a pointer to Drew's original post:
	http://lists.w3.org/Archives/Public/public-sws-ig/2004Jan/0024.html

I have a question about the use of reification. I notice that what I 
take to be the latest SWRL forgoes the reification sytnax altogether:
	http://www.daml.org/2003/11/swrl/rdfsyntax.html

For example:
     <swrl:classAtom>
       <swrl:classPredicate rdf:resource="&ulan;Artist"/>
       <swrl:argument1 rdf:resource="#x" />
     </swrl:classAtom>

Whereas DRS has something like:

<drs:Atomic formula>
	<rdf:subject rdf:resource="#x"/>
	<rdf:predicate rdf:resource="&rdf;type"/>
	<rdf:object rdf:resource="&ulan;Artist"/>
</drs:Atomic formula>

I'm not quibbling about having special support for classAtom, but about 
reusing the reification vocabulary at all. It leads to this bit of 
hair:

"""If a predicate has arity > 2, its rdf:object slot is Ūlled by a a 
term sequence,
represented as an OWL list of all arguments after the Ūrst."""

So sometimes the rdf:object is the argument and sometimes it's a 
pointer to the argument list. Why not just make up your own properties 
(liek swrl:argument1)? (Better, make the value of swrl:argument have 
structure like swrl:position, swrl:name, swrl:defaultValue :)) Or heck, 
just add as many rdf:objects as you'd like :)

Cheers,
Bijan Parsia.
Received on Wednesday, 14 January 2004 21:46:20 UTC

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