[Edu-sig] re: Mathobjects

[Kirby Urner]

Also, I meant to thank Daniel Ajoy in the simplematrix source 
for a sweet little recursive algorithm (which he shared in
Logo) for generating all those permutations needed by that 
greedy determinants algorithm.  I'm adding that thank you now
and re-uploading.

Finally, I never managed to completely solve the devils' 
embrace problem of importing pyfraction in polynomial, and
polynomial in pyfraction.  

Importing works when I just import, but I want to promote 
pyfraction.Fraction to the top level in polynomial, so I don't 
have to write pyfraction.Fraction all the time (especially 
inconvenient when expanding polynomials with factional 
coefficients just for evaluation purposes -- a way to stay 
with integer computations and avoid degenerating to floating 
points).... 

That's why you'll see an 'import Fraction from pyfraction', but
in the __call__ method of polynomial, and not up top, where it 
causes problems when I boot Python initially and go 
'from mathobjects import *' -- and even if I have an import
pyfraction statement first.

Any pointers would be appreciated.  I think I must be missing
something.

Kirby