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clipsequals-operator

Clips Not Equals To

Using the Clips programming language, what is the correct "not equals" syntax?

This is the not symbol ~

Clips Documentation

Solution

  • The ~ constraint is part of the pattern matching language. The neq function is for use within expressions. Both can be used with values of any type. The != and <> functions can only be used with numeric arguments. 

    CLIPS> (clear)
CLIPS>  
(defrule rule-1
   (color ?color&~red&~blue)
   =>
   (printout t "rule-1: " ?color crlf))
CLIPS>  
(defrule rule-2
   (color ?color)
   (test (and (neq ?color red) (neq ?color blue)))
   =>
   (printout t "rule-2: " ?color crlf))
CLIPS> (assert (color green) (color blue) (color yellow) (color red))
<Fact-4>
CLIPS> (run)
rule-1: yellow
rule-2: yellow
rule-1: green
rule-2: green
CLIPS> (neq 2 3)
TRUE
CLIPS> (neq a b)
TRUE
CLIPS> (!= 2 3)
TRUE
CLIPS> (!= a b)
[ARGACCES5] Function != expected argument #1 to be of type integer or float
CLIPS>