这个Codeigniter命令是什么意思？

I have a question. What does this command mean? Is it if or lambda?

This is the command I'm referring to:

$this->user_m->loggedin() == FALSE || redirect($dashboard);

It's the same thing like this:

if ($this->user_m->loggedin() == false) {
    redirect($dashboard);
}

See http://en.wikipedia.org/wiki/Short-circuit_evaluation