Re: Planning under Description Logic ?--an obstacle towards WSAC


this is just my 2 cents...
Manshan Lin wrote:

>hi all,
>I've just read all the discussion about applying AI planning technique to SWS.
>I notice that most traditional planning algorithm are based on first
>order logic, which is based on close-world assumption. And I also
>notice that in order
>to achieve true automatic composition of web service, we must tackle
>the problem of planning under description logic, which is based on
>open-world assumption.
that is true and Drew has also pointed that out in his paper
" *Estimated Regression Planning for Interactions with Web Services"

>The question is :
>When using DL to describe world state, what adaptions should
>traditional AI planning techniques make?
>For example,
>TBOX: EffectA = intersectionOf(EffectB,EffectC)
>ABOX: a individual EffectA
>Then we can choose an operation that achieves EffectA or we can choose
>two operations (one achieves EffectB and the other achieves EffectC).
>It's a little like adding some common rules 
>(in this case EffectB(x) and EffectC(x)->EffectA(x)) 
>to traditional planning domain. When EffectB and EffectC are not
>atomic concepts, the situation becomes more complex. How to handle
>this kind of things in planning algorithms?
I've experimented with the (rather old) PRODIGY planner  for SWS 
composition and supposedly it allows to
add axioms like this to planning domain descriptions. Manual at:
So your example would probably along the lines of

(Inference-Rule intersectionClass
 (params <x>)
  ((<x> Effect))
  (and (type <x> EffectB)
          (type <x> EffectC)))
  ((add (type <x> EffectA)))))

Basically, inference-rules are like operators except that they don't 
occur in the final plan.
However, I havn't really worked with this feature so far...
One problem is that Prodigy's type system only allows single inheritance. :(

Personally, I think that planning is not really the right approach to 
SWS composition.

You find many alternative approaches on
Situation calculus seems appealing but, of course, there is no usable 
and I don't know much about automation of it...


>Best regards!
>Manshan Lin 
>Affiliation: School of Computer Science and Engineering, the South
>China University of Technology
>Phone: (+86)13711287277

Received on Thursday, 2 December 2004 10:57:58 UTC