<?php

class superA{
	protected function a(){}
	public function aa(){}
}
class superB extends superA{
	protected function b(){		
		$this->a();// this works
		$this->aa(); // this works
	}
}
class superC extends superB{
	protected function c(){
		$this->a(); // this won't work
		$this->aa(); // this won't work
		$this->b(); // this works
	}
}