W3C home > Mailing lists > Public > public-sws-ig@w3.org > May 2005

Re: OWL-S: simple proposal to evolve logic expressions

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Fri, 20 May 2005 07:14:04 +0900
Message-Id: <fb9eabcebdbf3452657eca0ce9235676@isr.umd.edu>
Cc: public-sws-ig@w3.org
To: Daniel Elenius <daele@ida.liu.se>

On May 20, 2005, at 2:29 AM, Daniel Elenius wrote:

>> Rules in SWRL are just material conditionals. They most certainly
>> "evaluate" to true or false. They may be inferred.
> Hmm, ok, I take that back then.
>>> In fact, it may be easier to just do AtomLists (if there's a single
>>> Atom, then we just have a list with one element).
>> Prolly true. But if Preconditions are just formulae (rather than
>> restricted to conjunctions), there's no need to avoid imps.
> I guess the only reason would be that the any OWL-S tools (not just
> editing tools, but especially execution engines/planners) would need to
> understand Imps, whereas if just AtomLists are allowed, things are
> somewhat easier. Imps make things undecidable, right?

Hmm. Well, my guess is that OWL-S is undecidable for many reasons :) 
Making it OWL-Full (as removing quotation will do) might not *alone* do 
it, but it's prolly bad.

>  (Whereas AtomLists
> (with instantiated parameters) correspond to ABox queries.)

Hmm. Don't know that that's decidable if you allow undistinguished 
variables. Interesting question

> That may not
> be a reason to prohibit them though.

Yeah. A reason would be that such universal quantifications are just 
weird as a precondition. The counter would be, "So they're weird! Who 
cares? Let the chips fall!"

We certainly allow arbitrary KIF formulas.

Received on Thursday, 19 May 2005 22:14:11 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:54:14 UTC