Provided by: clips_6.24-3ubuntu1_amd64 

NAME
clips - an expert system programming language
SYNOPSIS
clips [ file.clp ]
DESCRIPTION
CLIPS is a productive development and delivery expert system tool which provides a complete environment
for the construction of rule and/or object based expert systems. CLIPS is being used by numerous users
throughout the public and private community including: all NASA sites and branches of the military,
numerous federal bureaus, government contractors, universities, and many companies. The key features of
CLIPS are:
Knowledge Representation
CLIPS provides a cohesive tool for handling a wide variety of knowledge with support for three
different programming paradigms: rule-based, object-oriented and procedural. Rule-based
programming allows knowledge to be represented as heuristics, or "rules of thumb," which specify a
set of actions to be performed for a given situation. Object-oriented programming allows complex
systems to be modeled as modular components (which can be easily reused to model other systems or
to create new components). The procedural programming capabilities provided by CLIPS are similar
to capabilities found in languages such as C, Pascal, Ada, and LISP.
Portability
CLIPS is written in C for portability and speed and has been installed on many different computers
without code changes. Computers on which CLIPS has been tested include an IBM PC running DOS and
Windows 95 and a Macintosh running MacOS and Mach. CLIPS can be ported to any system which has an
ANSI compliant C compiler. CLIPS comes with all source code which can be modified or tailored to
meet a user's specific needs.
Integration/Extensibility
CLIPS can be embedded within procedural code, called as a subroutine, and integrated with
languages such as C, FORTRAN and ADA. CLIPS can be easily extended by a user through the use of
several well-defined protocols.
Interactive Development
The standard version of CLIPS provides an interactive, text oriented development environment,
including debugging aids, on-line help, and an integrated editor. Interfaces providing features
such as pulldown menus, integrated editors, and multiple windows have been developed for the
Macintosh, Windows 95, and X Window environments.
Verification/Validation
CLIPS includes a number of features to support the verification and validation of expert systems
including support for modular design and partitioning of a knowledge base, static and dynamic
constraint checking of slot values and function arguments, and semantic analysis of rule patterns
to determine if inconsistencies could prevent a rule from firing or generate an error.
Fully Documented
CLIPS comes with extensive documentation including a Reference Manual and a User's Guide.
(provided in the Debian clips-doc package)
FILES
/usr/lib/clips/clips.hlp
The help for the CLIPS interpreter, type in (help) once the interpreter is run it to read it.
BUGS
CLIPS is old software so bugs are not unheard of.
HISTORY
The origins of the C Language Integrated Production System (CLIPS) date back to 1984 at NASA's Johnson
Space Center. At this time, the Artificial Intelligence Section (later the Software Technology Branch,
Client/Server Systems Branch, and now the Information Technology Office) had developed over a dozen
prototype expert systems applications using state-of-the-art hardware and software. However, despite
extensive demonstrations of the potential of expert systems, few of these applications were put into
regular use. This failure to provide expert systems technology within NASA's operational computing
constraints could largely be traced to the use of LISP as the base language for nearly all expert system
software tools at that time. In particular, three problems hindered the use of LISP based expert system
tools within NASA: the low availability of LISP on a wide variety of conventional computers, the high
cost of state-of-the-art LISP tools and hardware, and the poor integration of LISP with other languages
(making embedded applications difficult).
The Artificial Intelligence Section felt that the use of a conventional language, such as C, would
eliminate most of these problems, and initially looked to the expert system tool vendors to provide an
expert system tool written using a conventional language. Although a number of tool vendors started
converting their tools to run in C, the cost of each tool was still very high, most were restricted to a
small variety of computers, and the projected availability times were discouraging. To meet all of its
needs in a timely and cost effective manner, it became evident that the Artificial Intelligence Section
would have to develop its own C based expert system tool.
The prototype version of CLIPS was developed in the spring of 1985 in a little over two months.
Particular attention was given to making the tool compatible with expert systems under development at
that time by the Artificial Intelligence Section. Thus, the syntax of CLIPS was made to very closely
resemble the syntax of a subset of the ART expert system tool developed by Inference Corporation.
Although originally modelled from ART, CLIPS was developed entirely without assistance from Inference or
access to the ART source code.
The original intent for CLIPS was to gain useful insight and knowledge about the construction of expert
system tools and to lay the groundwork for the construction of a replacement tool for the commercial
tools currently being used. Version 1.0 demonstrated the feasibility of the project concept. After
additional development, it became apparent that CLIPS would be a low cost expert system tool ideal for
the purposes of training. Another year of development and internal use went into CLIPS improving its
portability, performance, functionality, and supporting documentation. Version 3.0 of CLIPS was made
available to groups outside of NASA in the summer of 1986.
Further enhancements transformed CLIPS from a training tool into a tool useful for the development and
delivery of expert systems as well. Versions 4.0 and 4.1 of CLIPS, released respectively in the summer
and fall of 1987, featured greatly improved performance, external language integration, and delivery
capabilities. Version 4.2 of CLIPS, released in the summer of 1988, was a complete rewrite of
CLIPS for code modularity. Also included with this release were an architecture manual providing a
detailed description of the CLIPS software architecture and a utility program for aiding in the
verification and validation of rule-based programs. Version 4.3 of CLIPS, released in the summer of 1989,
added still more functionality.
Originally, the primary representation methodology in CLIPS was a forward chaining rule language based on
the Rete algorithm (hence the Production System part of the CLIPS acronym). Version 5.0 of CLIPS,
released in the spring of 1991, introduced two new programming paradigms: procedural programming (as
found in languages such as C and Ada;) and object-oriented programming (as found in languages such as the
Common Lisp Object System and Smalltalk). The object-oriented programming language provided within CLIPS
is called the CLIPS Object-Oriented Language (COOL). Version 5.1 of CLIPS, released in the fall of 1991,
was primarily a software maintenance upgrade required to support the newly developed and/or enhanced X
Window, MS-DOS, and Macintosh interfaces. Version 6.0, released in the Spring of 1993, added fully
integrated object/rule pattern matching and support features for rule-based software engineering. Version
6.1, released in the Summer of 1998, added C++ compatibility and functions for profiling performance.
Because of its portability, extensibility, capabilities, and low-cost, CLIPS has received widespread
acceptance throughout the government, industry, and academia. The development of CLIPS has helped to
improve the ability to deliver expert system technology throughout the public and private sectors for a
wide range of applications and diverse computing environments. CLIPS is being used by over 5,000 users
throughout the public and private community including: all NASA sites and branches of the military,
numerous federal bureaus, government contractors, universities, and many private companies.
CLIPS is now maintained as public domain software by the main program authors who no longer work for
NASA.
There have appeared also derivative works from CLIPS like:
JESS The Java Expert System Shell, which provides a CLIPS interpreter for the Java programming
language.
fuzzyCLIPS
A fuzzy extension of CLIPS.
bw CLIPS A version of CLIPS using backward chains.
AUTHOR
As with any large project, CLIPS is the result of the efforts of numerous people. The primary
contributors have been: Robert Savely, previous branch chief of the STB and now chief scientist of
advanced software technology at JSC, who conceived the project and provided overall direction and
support; Chris Culbert, current chief of the Information Technology Office, who managed the project,
wrote the original CLIPS Reference Manual, and designed the original version of CRSV; Gary Riley, who
designed and developed the rule-based portion of
CLIPS , coauthored the CLIPS Reference Manual and CLIPS Architecture Manual, and developed the Macintosh
interface for CLIPS ; Brian Donnell, who designed and developed the CLIPS Object Oriented Language
(COOL), coauthored the CLIPS Reference Manual and CLIPS Architecture Manual, and developed the previous
MS-DOS interfaces for CLIPS ; Bebe Ly, who was responsible for maintenance and enhancements to CRSV and
is now responsible for developing the X Window interface for CLIPS; Chris Ortiz, who developed the
Windows 3.1 interface for CLIPS; Dr. Joseph Giarratano of the University of Houston-Clear Lake, who wrote
the CLIPS User's Guide; and Frank Lopez, who designed and developed CLIPS version 1.0 and wrote the CLIPS
1.0 User's Guide.
Many other individuals contributed to the design, development, review, and general support of CLIPS,
including: Jack Aldridge, Carla Armstrong, Paul Baffes, Ann Baker, Stephen Baudendistel, Les Berke, Tom
Blinn, Marlon Boarnet, Dan Bochsler, Bob Brown, Barry Cameron, Tim Cleghorn, Major Paul Condit, Major
Steve Cross, Andy Cunningham, Dan Danley, Mark Engelberg, Kirt Fields, Ken Freeman, Kevin Greiner, Ervin
Grice, Sharon Hecht, Patti Herrick, Mark Hoffman, Grace Hua, Gordon Johnson, Phillip Johnston, Sam
Juliano, Ed Lineberry, Bowen Loftin, Linda Martin, Daniel McCoy, Terry McGregor, Becky McGuire, Scott
Meadows, C. J. Melebeck, Paul Mitchell, Steve Mueller, Bill Paseman, Cynthia Rathjen, Eric Raymond, Reza
Razavipour, Marsha Renals, Monica Rua, Tim Saito, Gregg Swietek, Eric Taylor, James Villarreal, Lui Wang,
Bob Way, Jim Wescott, Charlie Wheeler, and Wes White.
SEE ALSO
/usr/share/doc/clips-common/CLIPS-FAQ In Debian systems, you will find the FAQ file compressed, use zcat
or zless to read it.
/usr/share/doc/clips-common/html/ You will find more documentation from upstream development in the html
directoryin Debian systems.
/usr/share/doc/clips-common/examples/ A number of examples of CLIPS program are available so you can test
the interpreter and learn how it works. You can, for example, load one of them with (load
"/usr/share/doc/clips-common/examples/wordgame.clp") and run it using (reset) and (run).
COPYRIGHT
This manpage was made by Javier Fernandez-Sanguino <jfs@debian.org> for Debian GNU/Linux (but may be
used by others)
Linux July 2003 CLIPS(1)