title: Drools: Evaluating a list of Events using 'After'
body: <p>I'm really new to drools and I am trying to get a hang of some different things. Right now I need to be able to determine whether certain events happen in a certain order. The problem is that this list of events is constantly changing. Right now I have do this:</p>
  
  <pre><code>$a: Hit(id == A)
  $b: Hit(id == B)
  $c: Hit(id == C)
  $d: Hit(id == D)
  $e: Hit(id == E)
  $f: Hit(id == F)
  
  Hit($b after $a)
  Hit($c after $b)
  Hit($d after $c)
  Hit($e after $d)
  Hit($f after $e)
  </code></pre>
  
  <p>I would like to do something more like this:</p>
  
  <p>global list events = [A, B, C, D, E, F]</p>
  
  <p>For each item in this list, there exists one of each event in the session all that happen in a particular order.</p>
  
  <p>F -> after -> E -> after -> D -> after -> C -> after -> B -> after -> A</p>
  
  <p>Would/Could I use an accumulator for something like this?</p>