I believe that there is no reason to have a default indeterminate x defined when SAGE starts, any more. I know I was basically one of the people advocating this, but Bill Page's principle of least surprise has convinced me that I'm wrong.
What I think *is* valuable, is being able to define: x = polygen() This is useful if one wants to introduce a placekeeping indeterminate. Here x will still be a universal indeterminate. But once you get rid of the default x that is introduced when SAGE starts, then obviously R = PolynomialRing(ZZ) has to be illegal. That is unless of course, you use this $.0 thing. I personally think SAGE should refer to them as R.0, R.1, etc, but maybe that causes problems somewhere else. Actually, this is one of the features of MAGMA that I abhor the most, so if it were me, I would just make R=PolynomialRing(ZZ) illegal. But I have to admit, there is also something unsettling about this. Perhaps there is a third way. But I have to admit to not being able to think of it right now. However, if we solve this problem, we will have removed one of the biggest obstacles to new users that MAGMA currently presents. Polynomials are totally fundamental things and anything we can do to make them easier and more natural to use will be a huge benefit to users of SAGE. --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
