architecture fixed_length_series of cos is
begin

  summation : process (theta) is
    variable sum, term : real;
  begin
    sum := 1.0;
    term := 1.0;
    for n in 1 to 9 loop
      term := (-term) * theta**2 / real(((2*n-1) * 2*n));
      sum := sum + term;
    end loop;
    result <= sum;
  end process summation;

end architecture fixed_length_series;