reserve A,B,C for Ordinal,
  K,L,M,N for Cardinal,
  x,y,y1,y2,z,u for object,X,Y,Z,Z1,Z2 for set,
  n for Nat,
  f,f1,g,h for Function,
  Q,R for Relation;
reserve ff for Cardinal-Function;
reserve F,G for Cardinal-Function;

theorem Th42:
  X is finite implies card X in card omega
proof
  assume X is finite;
  then ex n being Nat st ( card X = card n) by CARD_1:48;
  hence thesis;
end;
