axiom-developer
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Axiom-developer] Bug in GeneralizedMultivariateFactorize?


From: Stephen Wilson
Subject: [Axiom-developer] Bug in GeneralizedMultivariateFactorize?
Date: 11 Jul 2007 15:23:08 -0400
User-agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4

*,

I was hoping for some help with GeneralizedMultivariateFactorize
(GENMFACT) in allfact.spad.pamphlet.

The issue is with the following code, in particular with the call to
squareFree at the end:

   T == add
    factor(p:P) : Factored P ==
      R has FiniteFieldCategory => factor(p)$MultFiniteFactorize(OV,E,R,P)
      R is Polynomial(S) and S has EuclideanDomain =>
         factor(p)$MPolyCatPolyFactorizer(E,OV,S,P)
      R is Fraction(S) and S has CharacteristicZero and 
        S has EuclideanDomain =>
            factor(p)$MRationalFactorize(E,OV,S,P)
      R is Fraction Polynomial S =>
         factor(p)$MPolyCatRationalFunctionFactorizer(E,OV,S,P)
      R has CharacteristicZero and R has EuclideanDomain =>
               factor(p)$MultivariateFactorize(OV,E,R,P)
      squareFree p


Here, P satisfies a PolynomialCategory over an IntegralDomain.  But
such a P does not export squareFree unless the coefficient ring is a
GcdDomain.  This is a bug in GENMFACT, I believe.

I do not have the experience necessary with the algebra code yet to be
terribly efficient in determining what the proper fix here is.
Perhaps it is as simple as requiring GcdDomain.

Could anyone provide some insight here?

Many thanks!
Steve






reply via email to

[Prev in Thread] Current Thread [Next in Thread]