[net.lang.prolog] PROLOG Digest V3 #35

RESTIVO@SU-SCORE.ARPA (08/06/85)

From: Chuck Restivo (The Moderator) <PROLOG-REQUEST@SU-SCORE.ARPA>


PROLOG Digest             Monday, 5 Aug 1985       Volume 3 : Issue 35

Today's Topics:
                  Editorial - Digest Advertisements,
       Announcements - Call for papers & Flat Concurrent Prolog
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Date: Thu 1 Aug 85 20:21:26-PDT
From: Pereira@SRI-AI
Subject: Advertisements on the Prolog digest

I was disturbed to see what amounts to an advertisement to
POPLOG in the latest Prolog Digest. This would be acceptable
if POPLOG were a genuine academic system available to all
just for a handling fee, but this is only the case for UK
academic institutions (as the ad indicates near the end).
Others must acquire POPLOG from a commercial distributor
who sells it on behalf of Sussex University.

I think this use of the digest is unethical, infringes the
ARPANET rules and is unfair to other Prolog suppliers that
cannot or will not avail themselves of such a ``convenient''
form of free advertisement.

I leave you to reach your own conclusions about a software
supplier that uses such means to advertise its products.

-- Fernando Pereira

------------------------------

Date: Mon, 29 Jul 85 19:04:32 -0200
From: Ehud Shapiro  <Udi%wisdom.bitnet@WISCVM>
Subject: Call for papers


                           CALL FOR PAPERS

         Third International Conference on Logic Programming

        Imperial College of Science and Technology, London, UK

                           July 14-18, 1986


In cooperation with:

            Association for Computing Machinery
            British Computer Society
            IEEE Computer Society
            Japan Society for Software Science and Technology

The conference will consider all aspects of logic programming,
including, but not limited to:

        Theory and foundations
        Architectures and Implementations
        Methodology
        Programming Languages and Environments
        Applications
        Relations to other computation models, programming
        languages, and programming methodologies.

Of special interest are papers related to parallel processing,
papers discussing novel applications and applications that
address the unique character of logic programming, and papers
which constitute a contribution to computer science at large.

Papers can be submitted under two categories, short --
up to 2000 words,  and long -- up to 6000 words.  Submissions
will be considered on the basis of appropriateness, clarity,
originality, significance, and overall quality.

Authors should send eight copies of their manuscript, plus
an extra copy of the abstract, to:

        Ehud Shapiro
        ICLP Program Chairman
        The Weizmann Institute of Science
        Rehovot 76100, Israel.

Deadline for submission of papers is December 1, 1985.
Authors will be notified of acceptance or rejection
by February 28, 1986. Camera ready copies are due April
1st, 1986.

General Chairman

        Keith Clark
        Imperial College of Science and Technology
        180 Queen's Gate
        London SW7 2BZ, United Kingdom

Local Arrangements and Exhibition Chairman

        Richard Ennals
        Imperial College of Science and Technology
        180 Queen's Gate
        London SW7 2BZ, United Kingdom

Program Committee

        Martin van Caneghem, University of Marseille, France
        Veronica Dahl, Simon Fraser University, Canada
        Maarten van Emden, University of Waterloo, Canada
        Kazuhiro Fuchi, ICOT, Japan
        Koichi Furukawa, ICOT, Japan
        Ake Hanssen, Uppsala University, Sweden
        Kenneth M. Kahn,  Xerox PARC, USA
        Peter Koves, Logicware Inc., Canada
        Giorgio Levi, University of Pisa, Italy
        John Lloyd, University of Melbourne, Australia
        Frank G. McCabe, Imperial College, UK
        Jack Minker, Maryland University, USA
        Fernando Pereira, SRI International, USA
        Luis M. Pereira, University of Lisbon, Portugal
        Antonio Porto, University of Lisbon, Portugal
        Ehud Shapiro, Chairman, Weizmann Institute, Israel

------------------------------

Date: Fri, 26 Jul 85 15:25:56 -0200
From: Ehud Shapiro  <Udi%wisdom.bitnet@WISCVM>
Subject: Beta test-sites for our Flat Concurrent Prolog

We will be ready in a month or so to release our Flat
Concurrent Prolog system to beta test sites (FCP is the
And-parallel subset of Concurrent Prolog).  The system
consists of an emulator for a Warren-style FCP abstract
machine, written in C, which also includes kernels and a
garbage collector; an FCP compiler, written entirely in
FCP (including the tokenizer, parser, precompiler, encoder,
and assembler); and a basic interactive programming
environmnt that includes a shell, I/O routines, and a
source-level debugger, which are also written in FCP.

The system has an interesting module system, which implements
remote procedure calls via message-passing between module
manager processes.  It supports separate compilation and
runtime linking.

The system runs on VAX and on the Sun under Berkeley
Unix 4.2.  It runs at about the third of the speed of
Quintus Prolog on the Vax for similar programs, on a
wide range of examples.

Some statistics:  compiling the main module of the compiler,
the encoder, which is 8937  bytes and 418 lines of code
long, takes 258  CPU seconds on the VAX/750.  The resulting
binary file is 17560 bytes of code long (at present we use
word-encoding, rather then byte encoding for the abstract
machine instructions).  The compilation consumes about 1.5
Mbytes of heap memory (without garbage collection).

During this computation, 29000 processes are generated (yes,
twenty nine thousand), and altogether they perform 92000
reductions.  During the computation 13000 process suspensions
occur.  This gives an effective rate of 350 process reductions
per second, and an avarage of 3 reductions per process.

The system's C code is currently 5270 lines of code long, 2942
for the emulator, 1624 for kernels, and 704 for the garbage
collector.  Its FCP code is currently 4529 lines of code long,
2060  for the compiler, 324  for the debugger, 722  for I/O, and
1423  for the rest of the system.  Of course the interactive shell
and the compiler share the tokenizer and parser.

The main designers and implementors of the system are Avshalom
Houri and myself.  Other contributors include Bill Silverman,
Michael Hirsch, Jim Crammond, Colin Mierowski, Steve Taylor,
Muli Safra, Nir Friedman, and Shimon Cohen.  The development of
the system was supported by IBM Poughkeepsie, Data Systems
Division.

The system is still under development. The major avenues of
improvement being investigated at present are extending the module
system to be hierarchical, and to integrate better the debugging
and module concepts;  integrating the system with a partial
evaluator; improving the performance by optimizing the emulator
and improving the instruction set (we do not plan at present
rewriting  the emulator in assembler or in micro-code); adding
a window system; an independent file-system; and other gadgets.

Longer term research includes full compilation and implementation
on a multiprocessor.

We plan to distribute the system following standard university
basedsoftware distribution practices.  Before releasing the
system for the general public, we would like to obtain some
feedback, and improve the system some more.  We would like to
deliver it to some selected groups with strong logic programming
or concurrent programming background, who are interested in one
or more of the following:

1. Improve and extend the system in various ways.
2. Use it as a research tool for developing pilot FCP
   applications.
3. Use it to teach a course in concurrent logic programming.
   (we beleive it is reliable enough even at present for this.
   It has just begun to be used for doing course projects in
   my Concurrent Prolog Programming course at the Hebrew
   University and at the Weizmann Institute, so we will know
   better in a few weeks).

Interested parties should contact me, with relevant information,
at:
        udi%wisdom.bitnet@WISCVM.arpa
     or
        ...!decvax!humus!wisdom!udi

We hope to sort out the details of the distribution mechanism
by mid-August.

-- Ehud Shapiro

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End of PROLOG Digest
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