theorem
  W is epsilon-transitive implies Rank card Tarski-Class W = Tarski-Class W
proof
  assume W is epsilon-transitive;
  then Rank card Tarski-Class W is_Tarski-Class_of W by Th44;
  hence Rank card Tarski-Class W c= Tarski-Class W & Tarski-Class W c= Rank
  card Tarski-Class W by Th28,CLASSES1:def 4;
end;
