[PHP OOP Inheritence from different directory]

Ok so I'm trying to make a small framework for personal needs, just to speed up small project time.

 

My biggest issue right now is I want all the controllers in my application to inherit from one class the "skel_controller" but it needs to stay in a different directory. The directory structure looks like this

/root

  /app

      /application

        controller_for_app.php

  /libs

      /skel

        skel_controller.php

 

Can anyone help me with this?