Myth::Auth Login problem

Ok, thanks to a little research with the help of this Forum i found out that i need to add 'auth' to the BaseControllers $helpers property and make the AuthController extend the BaseController. Adding 'auth' to the AuthControllers own $helpers property somehow didnt work. Now i can use something like this im my views:
<?php if (logged_in()) : ?>
<h1>Logged in</h1>
<?php endif; ?>
And im being automatically redirected to the welcome-page by the AuthControllers login method. But why did i need to add 'auth' to the BaseControllers $helpers property to make the redirection working?