title: How to pass a parameter in defrule function? CLIPS
body: <p>I am new of CLIPS, thanks for your help.
  THE ISSUE:
  If I have below template:</p>
  <pre><code>(deftemplate user
    (slot id (type INTEGER))
    (slot firstname (type STRING))
    (slot lastname (type STRING))
    (slot username (type STRING))
    (slot average (type FLOAT))
    )
  </code></pre>
  <p>I would take the username value from facts and checking if there are two facts with same username but different average. For example, if We have:</p>
  <pre><code>(assert user (id 1) (firstname 'Mike') (lastname 'Mikeson') (username 'mike') (average 70.00))
  (assert user (id 1) (firstname 'Mike') (lastname 'Mikeson') (username 'mike') (average 10.00))
  (assert user (id 2) (firstname 'John') (lastname 'Johnson') (username 'john') (average 90.00))
  </code></pre>
  <p>I would count the facts with same username, so 'mike', and checking if first fact has same value in second fact in the average field.</p>
  <p>I tried searching on internet but there are few information about CLIPS</p>