class example
{
public function calc(){
$this->add();
$this->mul();
echo "calc() <br />";
}
private function add(){
echo "add() <br />";
}
private function mul(){
echo "mul() <br />";
}
public function div(){
echo "div() <br />";
}
}
$o = new example();
$o->calc();
$o->div();
/*
run:
add()
mul()
calc()
div()
*/