title: Why can you overwrite true but not false in namespaces?
body: <p>According to my tests on <a href="http://3v4l.org/ZCJWA" rel="nofollow">http://3v4l.org/ZCJWA</a> following example (For PHP 5.3.10 - 5.4.6):</p>
  
  <pre><code>&lt;?php
  namespace Foo;
  define('Foo\\true', false);
  define('Foo\\false', true);
  
  var_dump(
      true,
      false,
      1 === 1,
      1 === 0
  );
  </code></pre>
  
  <p>will return:</p>
  
  <pre><code>bool(false)
  bool(false)
  bool(true)
  bool(false)
  </code></pre>
  
  <p>Why can you overwrite <code>true</code> with <code>false</code> but not <code>false</code> with <code>true</code>?</p>