For you php noob.

gistfile1.txt

absract class parent {

    abstract function childMethod();

    function parentMethod(){
        $this->childMethod();
    }
}

class foo extends parent {
    function childMethod(){
        return 'I am child';
    }
}

$o = new foo();
echo $o->parentMethod()->childMethod();

abstract *

Actually, I tried it now, it does not work at all. I even modified 'parent' changing it to non-reserved keywords and still gives an error.