reserve X,Y,Z,X1,X2,Y1,Y2 for set, x,y,z,t,x1,x2 for object,
  f,g,h,f1,f2,g1,g2 for Function;

theorem Th34:
  rng f c= Funcs(X,Y) implies rng uncurry f c= Y & rng uncurry' f c= Y
proof
A1: Funcs(X,Y) c= PFuncs(X,Y) by FUNCT_2:72;
  assume rng f c= Funcs(X,Y);
  then rng f c= PFuncs(X,Y) by A1;
  hence thesis by Th33;
end;
