Defining a binary operator between function access types: Is it possible?

[soychangoman@gmail.com]

I'm trying to define a binary operator between function access types
that returns the access to the function that is the binary operator
acting on both functions. Let's put it a bit clearer:

-----------
procedure operating_on_access is

  type function_access is access function ( x : Real) return Real;

  function "+" (f1 : function_access; f2 : function_access) return
function_access is
  begin
     -- The question is what to put here
  return null;
  end "+"

  funcion square (x : Real) return Real is
  begin
      return x**2;
  end square;

  funcion cubic (x : Real) return Real is
  begin
      return x**3;
  end square;

  f1_acc,   f2_acc,   f3_acc : function_access;

begin

  f1_acc := square'Access;
  f2_acc := cubic'Access;

  -- f3_acc := f1_acc + f2_acc;
-- the idea is that ' f3_acc.all ( x )  ' and ' square (x) + cubic(x)
' are equivalent

end operating_on_access;
-----

Thanks in advance

Matías Niklison