I think you want the multivariate Laurent series to form a field. For
x + y to have an inverse, you should additionally make a choice of an
ordering x < y or y < x to decide what its series expansion looks
like. The best definition might therefore be the iterated Laurent
series, as described in Chapter 2 of this PhD thesis:
http://arxiv.org/pdf/math/0405133.
This might also be the easiest to implement.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to sage-devel@googlegroups.com
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at http://groups.google.com/group/sage-devel
URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/
-~----------~----~----~----~------~----~------~--~---
