W3C home > Mailing lists > Public > public-rif-wg@w3.org > January 2007

Re: Outcomes from Jan 2 telecon

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Wed, 03 Jan 2007 11:00:07 +0000
Message-ID: <459B8CB7.6050404@hplb.hpl.hp.com>
To: Chris Welty <cawelty@gmail.com>
CC: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>

Chris Welty wrote:
> 
> 
> Although we came to no resolutions today, I remain optimistic that we 
> are close to having something for the RIF Core.  I want again to 
> summarize what I think happened today to be sure I understood it, 
> especially the cases where I thought there was agreement.
> 
> The main technical discussion at today's telecon centered again on the 
> idea of "slots."
> 
> Harold agreed that the positional -> keyword mapping with predicate 
> signatures would address his concerns.
> 
> Michael however pointed out that there are at least three semantics in 
> use for "slots": relational, psi-terms, and the (nameless?) semantics 
> used by F-Logic.  He is working on a document that clarifies what these 
> semantics are, which will be out within the next day or so.
> 
> Hassan wasn't sure at first that this was any problem, suggesting that 
> we keep one syntax and let the constraints carry these semantics. 
> Several people felt that the differences should be reflected in the 
> syntax as well, i.e. a different syntax for each "kind" of slot. Hassan 
> disagreed, but Michael claimed to have some use cases from users of 
> F-Logic that they might want a single rule set that supported more than 
> one of these semantics.  Hassan then seemed to agree that if the 
> different "kinds" of slots were to be mixed in a single ruleset, they 
> should in fact be identified in syntax.

Excellent summary up to that point.

Then there was discussion on which, if any, of those three should go in 
the core. Gerd suggested that rather than have all three in the core we 
pick one based on use cases, I thought that received fairly broad agreement.

[I was going to insert an appeal to the charter in here but the charter 
isn't helpful. It says:

    """In order to allow interoperability with RDF and object-oriented 
systems, the syntax must support named arguments (also called "role" or 
"slot" names), allowing n-ary facts, rules, and queries to be provided 
through property/value interfaces."""

Justifying slotted syntax based on RDF makes little sense to me but 
presumably would correspond to the relational semantics, whereas 
interoperability with object-oriented systems would presumably be better 
served by one of the other semantics.]

Dave
Received on Wednesday, 3 January 2007 11:00:44 GMT

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