From: bernard@droopy.laas.fr
Newsgroups: fj.mail-lists.parallel
Subject: Re:  Formal Specifications in CCS
Date: 25 Aug 92 14:56:56 GMT
Distribution: fj

Hello,

About your recxent post on comp.parallel.

> I am keen to learn of any efforts in the use of CCS as a specification
> tool, or its use in the specification of such parallel paradigms.

I'am working since several years on the design and implementation of a
programming language (called LCS) based upon Standard ML and CCS. 

An implementation of  LCS is available  since mid 91;  it is perfectly
convenient for writing and runing CCS programs.

You will find  below the standard ftp  distribution notice. Please let
me know if you need more specific information.

Bernard.



========================================================================
Summary of LCS + distribution info.

----------------------------------------------------------------------
Summary of features:

LCS (a Language for Communicating Systems) is designed as an extension
of Standard ML with behaviors and processes  based upon  an high order
extension of Robin Milner's CCS formalism.

Behaviors are defined in an SML framework as values of specific types,
which may be turned into processes.  LCS supports all constructions of
CCS, plus  higher   order (behaviors  are   legal  messages), computed
communication  lines,  support  of  side  effects  (strong  and  light
processes) and an exception mechanism at process level. Behavior types
assign possibly  polymorphic  types  with every  communication labels.
Besides  behaviors and  processes,  LCS implements  a number of  other
extensions  to SML, either resulting  from  the process extension,  or
independent from it.

Two  user interfaces  are   provided:  an Execution  interface  and  a
Simulator.     In  addition to   the   capabilities of  a Standard  ML
environment,  the LCS executive adds  those of defining behaviors  and
managing processes created from these behaviors.  The simulator allows
the user  to  control  the  expansion of a   behavior, with tracing of
communications.  The simulator was primarilly  provided as a debugging
tool for LCS programs, but it also makes a valuable tool  for teaching
or learning CCS.

LCS is implemented as a byte code  interpreter; it is reasonnably fast
and  robust. Binaries and core image  files are small, core images are
portable accross machines. LCS may  run with as low  as 1MB of virtual
storage, thought  2 to  4 MB are   more  appropriate; memory  usage is
adaptative, and tunable by the user.

The LCS project is partially supported by CNRS/Greco C-Cube.


----------------------------------------------------------------------
The distribution:

LCS   V3.0 is available  for  Sun3 and Sun4  workstations, under SunOS
4.1.1. The  package  may be obtained by  ftp (server site laas.laas.fr
(140.93.0.15),  login  as  anonymous with   your username as password,
directory /pub/lcs); or by reel or streamer tape, on  request (send us
a  tape, dont  forget your address, our address  is at the end of this
message).

The ftp distribution is constituted of the following files:

README                  directives for installation
V3-0.tar.Z              libraries, man pages and miscellaneous
doc.tar.Z               users manual and other reports
bin.tar.Z               core image files for all targets
sun3_4.1.1.tar.Z        binaries for SUN3 under SunOS 4.1.1
sun4_4.1.1.tar.Z        binaries for SUN4 under SunOS 4.1.1

Copy  files README, V3-0.tar.Z,  doc.tar.Z, bin.tar.Z  and  the binary
file(s) for   your   machine(s) and  operating system(s);  install  as
explained in file README.

If   you just want   informations   about   the language  and/or   its
implementation,  then  copy file doc.tar.Z  only; it  packs  the users
manuals   and  a  short    report overviewing   the   project and  the
implementation (beware, this  report  uses an obsolete syntax  for the
language).


----------------------------------------------------------------------
The mailing list:

mail:                   for:
lcs-request@laas.fr     registration/deletion to the lcs list
lcs@laas.fr             contributions to the lcs list
lcs-bugs@laas.fr        bug reports
bernard@laas.fr         any other reasons


----------------------------------------------------------------------
Contact:

Bernard Berthomieu
LAAS-CNRS, 7, Avenue du Colonel Roche, F-31077 Toulouse Cedex
e-mail: bernard@laas.fr
phone:  (+33) 61 33 64 08
fax:    (+33) 61 55 35 77