reserve m for Cardinal,
  A,B,C for Ordinal,
  x,y,z,X,Y,Z,W for set,
  f for Function;
reserve f,g for Function,
  L for Sequence,
  F for Cardinal-Function;

theorem Th28:
  Rank card Tarski-Class W c= Tarski-Class W
proof
A1: card Tarski-Class W is limit_ordinal by Th21;
  let x be object;
  assume x in Rank card Tarski-Class W;
  then consider A such that
A2: A in card Tarski-Class W and
A3: x in Rank A by A1,CLASSES1:31;
  A in On Tarski-Class W by A2,Th9;
  then Rank A c= Tarski-Class W by Th7,Th25;
  hence thesis by A3;
end;
