<?php

class System
{
  /* @var Database */
  var $Database;

  function __construct()
  {
    $this->Database = new Database();
  }
}

class Base
{
  /** @var Application */
  var $System;
  /* @var Database */
  var $Database;

  function __construct(Application $System)
  {
    $this->System = &$System;
    $this->Database = &$System->Database;
  }
}

class Model extends Base
{

}

class View extends Base
{

}

class Controller extends Base
{

}