title: How can I compare a variable that is passed to a function with a string in CLIPS?
body: <p>When I tried to compare a variable with a string, it gives me an error. I tried to compare it with <code>(= ?a "s")</code>.</p>
  
  <p>This is the full code example that produces the error:</p>
  
  <pre><code>(deffunction cierto (?a)
    (if (= ?a "s")
      then
        (printout t TRUE crlf)
      else
        (printout t FALSE crlf)
    )
  )
  </code></pre>
  
  <p>The error:</p>
  
  <pre><code>Defining deffunction: cierto
  [ARGACCES5] Function = expected argument #2 to be of type integer or float
  
  ERROR:
  (deffunction MAIN::cierto
     (?a)
     (if (= ?a "s")
  FALSE
  </code></pre>