Path: utzoo!attcan!uunet!wuarchive!emory!hubcap!chassin
From: chassin@csinn.uucp (Jacques Chassin de Kergommeaux)
Newsgroups: comp.parallel
Subject: Re: Parallel constraint solving
Keywords: constraints, parallel
Message-ID: <11071@hubcap.clemson.edu>
Date: 22 Oct 90 12:40:53 GMT
References: <10906@hubcap.clemson.edu>
Sender: fpst@hubcap.clemson.edu
Reply-To: chassin@csinn.UUCP (Jacques Chassin de Kergommeaux)
Organization: Cap Gemini Innovation, Grenoble, France
Lines: 37
Approved: parallel@hubcap.clemson.edu

In article <10906@hubcap.clemson.edu> kddlab!icot32.icot.or.jp!hawley@uunet.UU.NET (David John Hawley) writes:
>In article <10852@hubcap.clemson.edu> laffra@serc.nl (Chris Laffra) writes:
>>Question:
>>
>>Does anybody out there has any experience with, or pointers to
>>parallel solving of constraint languages problems?
>
>There were some initial results published by the CHIP (constraint
>logic programming language) group at ECRC, on combining finite-domain
>constraints (i.e. CSP) with the PEPSys parallel logic programming
>language/system.  I've heard rumours that this work has been abandoned
>because of poor performance.
>
 
The work you are mentioning was performed by Pascal van Hentenryck from the
CHIP team with the support of myself from the PEPSys team.  Some results have
been published in the 6th.  ICLP at Lisboa, in 1989.  In addition to the
published results, many other *real* programs have been run.  Contrary to the
"rumours", performances were *excellent*.  Later on, the Sequent Balance
prototype was ported on Sequent Symmetry by Pierre Heuze', who used it to 
develop a secondary structure prediction program, with again *excellent* results
(published at ECRC, as ElipSys research report number 10, in december 1989).

The fact that Pascal Van Hentenryck is now at Brown (pvh@cs.brown.edu), 
Pierre Heuze' at Paris and myself at Grenoble is perhaps a better explanation 
for this work being abandoned than poor performances.
Next time you should check real information instead of reproducing uncontrolled
"rumours".

            Jacques Chassin de Kergommeaux
            CAP-GEMINI-Innovation
            7, Chemin du Vieux Che^ne, ZIRST,
            F-38240 Meylan, France.
              
            Tel: (+33) 76 76 47 55
            Fax: (+33) 76 41 06 29
            E-mail: chassin@capsogeti.fr