This thread feels very much like a solution looking for a problem. But on one narrow point, I'm trying to think of everything in the standard library or builtins that actually forms a total order with elements of the same type. * Not floats * I think not strings with unicode canonical equivalence, decomposition, and normalization * Definitely not sets, tuples, lists, dicts, etc. * Arguably not Decimal because it is sensitive to decimal context * Complex clearly not * I think not datetimes under timezone issues (although any ordering is certainly *wrong* given the vagaries of timezones) * Queues, deques, etc. don't even try, nor should they * Do array.array's lack even a partial order? So really I think we are left with wanting a test for whether something is "int or Fraction". -- Keeping medicines from the bloodstreams of the sick; food from the bellies of the hungry; books from the hands of the uneducated; technology from the underdeveloped; and putting advocates of freedom in prisons. Intellectual property is to the 21st century what the slave trade was to the 16th.