title: PHP constants undefined - but they are defined!
body: <p>I'm using constants to set various configuration variables within a script. </p>
  
  <p>The INC_PATH constant is defined within the script that includes the class library.</p>
  
  <pre><code>define('INC_PATH',$_SERVER['DOCUMENT_ROOT'].'includes/');
  include('class.lib.php');
  </code></pre>
  
  <p>The class library contains various include('someClass.php') lines. It also contains:</p>
  
  <pre><code>require(INC_PATH.'DB.class.php');
  </code></pre>
  
  <p>The class library throws a notice:</p>
  
  <pre><code>Use of undefined constant INC_PATH - assumed 'INC_PATH'
  </code></pre>
  
  <p>How is the class library not able to see that the INC_PATH constant has been defined? I thought constants were global? </p>