- From: Sheila McIlraith <sam@KSL.Stanford.EDU>
- Date: Sat, 1 Jun 2002 12:43:30 -0700 (PDT)
- To: monika@dmu.ac.uk, www-ws@w3.org
- Cc: daml-process@bbn.com
Dear Monika, DAML-S is a DAML+OIL ontology. As such, the semantics of DAML-S is well-defined by the semantics of DAML+OIL. There are 2 papers describing the semantics of DAML+OIL: a model-theoretic semantics, typical of description logics, http://www.daml.org/2001/03/model-theoretic-semantics and a so-called "axiomatic" semantics, that provides a set of axioms translating DAML+OIL to first-order logic and describing the intended interpretation of DAML+OIL in this richer languge. http://www.ksl.stanford.edu/people/dlm/daml-semantics/abstract-axiomatic-semantics.html So, the semantics of DAML-S is defined in terms of the semantics of DAML+OIL. Of course there is a "BUT"..... Recall however that DAML-S is comprised of a variety of different ontologies including a profile ontology, a process model and a grounding. The intended interpretation of the profile ontology and the grounding ontology are well captured by the semantics of DAML+OIL. The semantics of the process model is somewhat problematic because DAML+OIL is not sufficiently expressive to allow us to constrain our process models to ensure all and only the *intended* interpretation of the DAML-S process model. While the interpretation is likely (fairly) clear to the reader, from a formal perspective, we need to further constrain the ontolgy to ensure that it is accurately defined. Unfortunately, we cannot do so using the language constructs DAML+OIL provides. E.g., three items that are problematic are the representation of state for the evolution of the system, 2nd order induction for looping constructs, and constraints that cause the interpretation of DAML+OIL to be cyclic, such as dataflow constraints between outputs and inputs of composed processes. (Recall decidability of DAML+OIL is enforced by ensuring an acyclic interpretation of the associated graph.) There have been several pieces of work on defining a semantics for the process model for DAML-S. None is complete, but they are of utility. Both use the approach of specifying the semantics by appealing to a richer (more expressive) language. Recall that the process model appeals to both an "action metaphor" and a "function metaphor" for services. As such, the various semantic encodings appeal to different formalisms to elucidate aspects of the DAML-S process model. Each has its merits and limitations and the Coalition is working towards a unified model. - Narayanan, S. and McIlraith, S., "Simulation, Verification and Automated Composition of Web Services", Proceedings of the Eleventh International World Wide Web Conference (WWW-11), Honolulu, Hawaii, May, 2002. present a model-theoretic semantics for the core of the DAML-S process model by relating it to the situation calculus, a first-order logical language for reasoning about action and change. This has utility in relating DAML-S to AI-related inference techniques for composition. This paper also provides a distrubuted operational semantics for DAML-S in terms of Petri Nets. - Anupriya Ankolekar, Frank Huch, Katia Sycara, "Concurrent Execution Semantics for DAML-S with Subtypes", to appear in The First International Semantic Web Conference (ISWC), June, 2002. also presents an execution semantics for the DAML-S process model with subtypes. It is similar in spirit to the Petri-Net approach, but with some interesting differences, as discussed by the authors in the paper. I hope this helps. There is of course, a great deal to say on this subject and this only touches the surface. *** all papers refernced above can be found at http://www.daml.org/services Best regards, Sheila McIlraith ============================================================================== Sheila McIlraith, PhD Phone: 650-723-7932 Research Scientist Fax: 650-725-5850 Knowledge Systems Lab Department of Computer Science Gates Sciences Building, 2A-248 http://www.ksl.stanford.edu/people/sam Stanford University E-mail sam@ksl.stanford.edu Stanford, CA 94305-9020 From www-ws-request@w3.org Fri May 31 06:13:57 2002 Resent-Date: Fri, 31 May 2002 09:12:53 -0400 (EDT) Resent-Message-Id: <200205311312.g4VDCrU17390@frink.w3.org> Date: Fri, 31 May 2002 14:13:14 +0100 From: Monika Solanki <monika@dmu.ac.uk> User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.4) Gecko/20011128 Netscape6/6.2.1 X-Accept-Language: en-us MIME-Version: 1.0 To: www-ws <www-ws@w3.org> Subject: Formal Semantics for DAML-S Resent-From: www-ws@w3.org X-Mailing-List: <www-ws@w3.org> archive/latest/350 X-Loop: www-ws@w3.org Resent-Sender: www-ws-request@w3.org List-Id: <www-ws.w3.org> List-Help: <http://www.w3.org/Mail/> List-Unsubscribe: <mailto:www-ws-request@w3.org?subject=unsubscribe> X-Status: --------------010005090808020109060303 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi all!!!!! I am interested in papers related to formal semantics of the DAML-S language. Are there any such documents available? Any help appreciated. Regards, Monika -- >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< Monika Solanki De Montfort University Software Technology Research Laboratory Hawthorn building, H00.18 The Gateway. Leicester LE1 9BH, UK phone: +44 (0)116 250 6170 intern: 6170 email: monika@dmu.ac.uk <mailto:monika@dmu.ac.uk> web: http://www.cse.dmu.ac.uk/~monika/ <http://www.cse.dmu.ac.uk/%7Emonika/> >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< --------------010005090808020109060303 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit <html> <head> </head> <body> Hi all!!!!!<br> <br> I am interested in papers related to formal semantics of the DAML-S language. Are there any such documents<br> available?<br> <br> Any help appreciated.<br> <br> Regards,<br> <br> Monika<br> <div class="moz-signature">-- <br> >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< <br> Monika Solanki<br> De Montfort University <br> Software Technology Research Laboratory<br> Hawthorn building, H00.18 <br> The Gateway. <br> Leicester LE1 9BH, UK <br> <br> phone: +44 (0)116 250 6170 intern: 6170<br> email: <a href="mailto:monika@dmu.ac.uk">monika@dmu.ac.uk</a> <br> web: <a href="http://www.cse.dmu.ac.uk/%7Emonika/">http://www.cse.dmu.ac.uk/~monika/</a> <br> >**<>**<>**<>**<>**<>**<>**<>**<>**<>**< <br> </div> </body> </html> --------------010005090808020109060303--
Received on Saturday, 1 June 2002 15:44:23 UTC