89     def diff_diff(self, other):  argument
100     def ratio(self, other):  argument
116     def __add__(self, other):  argument
119     def __sub__(self, other):  argument
122     def __mul__(self, other):  argument
197     def diff_diff(self, other):  argument
204     def ratio(self, other):  argument
211     def __add__(self, other):  argument
214     def __sub__(self, other):  argument
217     def __mul__(self, other):  argument
220     def __lt__(self, other):  argument
225     def __gt__(self, other):  argument
228     def __le__(self, other):  argument
231     def __ge__(self, other):  argument
320     def __add__(self, other):  argument