In the book "Foundations of Set Theory" by Fraenkel, Bar-Hillel and Levy (second edition, 1973), on page 153, there is the following statement about Ackermann set theory:
"By means of the axiom of foundation one can prove the existence of the class $P(V)$ which consists of all subclasses of $V$." ($V$ is the class of all sets).
My question is:
Is there a proper class $X$ in Ackermann set theory, for which $P(X)$ does not exist in Ackermann set theory?
($P(X)$ is the collection of all subclasses of $X$.)
