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
  W is Tarski & A in On W implies card Rank A c= card W
proof
  assume that
A1: W is Tarski and
A2: A in On W;
  card Rank A in card W by A1,A2,Th25;
  hence thesis by CARD_1:3;
end;
