polynomial arithmetic over ginac

[Parisse Bernard]

> Thanks for your contribution.  We are quite interested in this.  Just a
> remark: you know about Victor Shoup's library NTL that does highly
> efficient factorization for univariate polynomials?  It was recently
> relicensed under GPL and thus it is possible to merge code with GiNaC.
> It is available from <http://www.shoup.net/ntl/>.
> 

  OK, I had a look now and there are major differences between NTL
and the polynomial library I'm working on:
1/ NTL handles *univariate* polynomials, not multivariate polynomials.
2/ the representation of polynomial of NTL is *dense*, not sparse.
  Therefore I don't think that NTL would be well suited for Groebner
basis calculations for example. On the other hand, it will be more
efficient 
for univariate factorization than any code I could write with
multivariate
polynomials, but that should be only by a constant factor (for generic
input; since I do not plan to add heuristics to the distinct degree
factorization+ Cantor-Zassenhaus right now, some inputs might be much
faster with NTL). Moreover, considering that the NTL compiled library is 
2.6M, I prefer to finish my factorization code: one of my objective is 
to be able to run a free CAS on one of these linux-handheld PC one
day...
  Anyway, thanks for the reference, it's always nice to have code and
tests inputs, especially since MuPAD factorization code is not
always well commented, not free, and they do not publish their tests as
far as I know.

Bernard