> I'm pretty sure it *was* merged:  math.sum should be the full-precision 
> summation in both recent betas (2.6b2 and 3.0b2).  Try comparing
> sum([1e100, 1, -1e100, -1]) and math.sum([1e100, 1, -1e100, -1])---they 
> should produce -1.0 and 0.0 respectively.

They do.  I realize now that two different built-in funcs in two 
different modules but with the same name will give the same 
representation.  That is so unusual, I was not expecting it.

> The name change to fsum only happened in the last few days.

Which will prevent the confusion I had ;-).  Good idea.