********************************************************************
    ELECTRONIC NEWSLETTER ON  REASONING ABOUT ACTIONS AND CHANGE        
Issue 99015             Editor: Erik Sandewall             18.5.1999
         Back issues available at http://www.etaij.org/rac/
********************************************************************



                    *********  TODAY  *********

Today we have the pleasure to announce that the ETAI submitted article
by Chitta Baral and Son Cao Tran have been accepted following the
recommendations of both the referees. The referee reports follow below.


              *********  ETAI PUBLICATIONS  *********

            ---  DISCUSSION ABOUT RECEIVED ARTICLES  ---

The following debate contributions (questions, answers, or comments)
have been received for articles that have been submitted to the ETAI and
which are presently subject of discussion. To see the full context,
for example, to see the question that a given answer refers to, or to
see the article itself or its summary, please use the web-page version 
of this Newsletter.

        ========================================================
        |  AUTHORS: Chitta Baral and Son Cao Tran
        |  TITLE:   Relating Theories of Actions and Reactive Control
        |  PAPER:   http://www.ep.liu.se/ea/cis/1998/009/
        |  REVIEW:  http://www.ida.liu.se/ext/etai/ra/rac/011/
        ========================================================

--------------------------------------------------------
|  FROM: Anonymous Referee 1
--------------------------------------------------------

1.  Are the results of the article, as specified in the summary, of 
significant interest for researchers in our area?

Yes.

2.  Does the full text substantiate the claims made in the summary?

Yes.

3.  Is the text intelligible and concise?

Yes. (Additional comments concerning minor corrections are being given
to the authors).

4.  Do you know of any previous publication of the same result?

No.

5.  Are there any other considerations that may affect the decision?

No.


--------------------------------------------------------
|  FROM: Anonymous Referee 2
--------------------------------------------------------

This paper concerns an important topic, namely the connection between
action theories and control. The paper is correct and well-written and
I think that the paper should be accepted. However, I have one
objection to make.

If  we instead of "action theory" use the term "open-loop
specification" and instead of "reactive control" use "control law" the
results of the paper concern the topic of verification and synthesis of
control laws w.r.t. to some specification. In this sense the results
are not at all original, since these research problems have generated
an abundance of work in Control Theory (more precisely,  in work on
"Discrete Event Dynamic Systems", DEDS). The authors appear to be
completely unaware of this work and on a number of points they 
re-invent the wheel (e.g. the criterion  for "correctness of
maintenance control modules" corresponds exactly to a particular
flavour of stability criteria, see [3]). There is not one single
reference to the DEDS (or Hybrid Systems) literature in the
bibliography.

It is important to incorporate the achievements in Reasoning about
Action and Change with control, but I think that it would be
unfortunate if achievements in Control Theory are neglected while doing
so.

Examples from the literature of control law synthesis and verification
for discrete and hybrid systems can be found in [1, 2, 5], and various
definitions of stability in [3, 4].

REFERENCES

[1] Heymann, Lin and Meyer, Controller Synthesis for a class of hybrid
systems subject to configuration-based safety constraints, LNCS 1201,
1997.

[2] Kumar and Garg, Modeling and Control of Logical Discrete Event
Systems, Kluwer Academic Publishers, 1995.

[3] Ozveren, Willsky and Antsaklis, Stability and Stabilizability of
Discrete Event Dynamic Systems, Journal of the ACM, 1991

[4] Passino and Burgess, Stability analysis of discrete event systems,
John Wiley, 1998.

[5] Zhang and Macworth, Synthesis of hybrid constraint-based
controllers, LNCS 999, 1995.


********************************************************************
 This Newsletter is issued whenever there is new news, and is sent
 by automatic E-mail and without charge to a list of subscribers. 
 To obtain or change a subscription, please send mail to the editor,
 erisa@ida.liu.se. Contributions are welcomed to the same address.
 Instructions for contributors and other additional information is
 found at:   http://www.etaij.org/rac/
********************************************************************