'CLIPS' is a
public-domain software tool for building
expert systems. The name is an acronym for "
C Language Integrated
Production System." The syntax and name was inspired by
Charles Forgy's
OPS ("Official Production System," although there was nothing really official about it). The first versions of CLIPS were developed starting in
1985 at
NASA-
Johnson Space Center (as an alternative for existing system ART
★ Inference) until the mid
1990s when the development group's responsibilities ceased to focus on expert system technology.
CLIPS is probably the most widely used expert system tool because it is fast, efficient and free. Although it is now in the public domain, it is still updated and supported by the original author, Gary Riley. CLIPS incorporates a complete
object-oriented language ''COOL'' for writing expert systems. Though it is written in
C, its interface more closely resembles that of the
programming language LISP. Extensions can be written in C, and CLIPS can be called from C.
Like other expert system languages, CLIPS deals with rules and facts. Various facts can make a rule applicable. An applicable rule is then asserted. Facts and rules are created by first defining them, as shown below:
(deffacts trouble_shooting
(car_problem (name ignition_key) (status on))
(car_problem (name engine) (status wont_start))
(car_problem (name headlights) (status work))
)
(defrule rule1
(car_problem (name ignition_key) (status on))
(car_problem (name engine) (status wont_start))
=>
(assert (car_problem (name starter) (status faulty))
)
Descendants of the CLIPS language include
Jess (rule-based portion of CLIPS rewritten in
Java, it later grew up in different direction),
Haley Eclipse,
FuzzyCLIPS (which adds concept of relevancy into the language),
EHSIS (that adds support for
GUI,
Multimedia,
IPC, etc. on
Windows) and others.
A college textbook about CLIPS, ''Expert Systems: Principles and Programming'' (ISBN 0-534-95053-1) is available, as well as a book on Jess, ''Jess in Action: Rule Based Systems in Java'' (ISBN 1-930110-89-8). CLIPS also contains extensive set of readable documentation.
External links
★
Homepage of the project
★
What is CLIPS, an explanation
★
NASA CLIPS: downloads, information, news, and history
★
CLIPS expert system tool: a candidate for the Diagnostic System engine