title: inheritance from two parent classes
body: <p>I read about this ages ago but never tried it now I can't remember if this is possible or not. Is it possible to extend a class from two parents on php5 e.g.</p>
  
  <p>class_d extends class_c and class_b</p>
  
  <p>moreover can you do this if class_c and class_b are themselves extended from class_a ... so you get something like this</p>
  
  <pre><code>                          class_a
                    class_b          class_c
                            class_d
  </code></pre>