I think the problem was not in Singular but in the Sage code for division of polynomials. There is a ticket, https://trac.sagemath.org/ticket/17638. I may help but my skills are not enough to solve the problem.
El martes, 22 de noviembre de 2016, 19:18:07 (UTC+1), Justin C. Walker escribió: > > > On Nov 22, 2016, at 05:40 , Dima Pasechnik wrote: > > > > > On Tuesday, November 22, 2016 at 12:19:37 PM UTC, Sho Takemori wrote: > >> > >> Thank you very much for your explanation. I have seen your post at > >> sage-devel before, but completely forgot it. > >> > >> I guess it would be better to raise an error or print a message than to > >> return a wrong result, if it is a known bug and not fixed yet. > >> > > > > In fact, Singular 4.0.3 (now in Sage 7.5.beta3) > > does the right thing: > > > >> ring r=0,(a),ls; > >> (1/2+a)/(1+2*a); > > 1/2 > > > > (same if I use more variables while defining r, not just one) > > > > Thus I guess Sage does not get from Singular the data right... > > I see the same with Singular 3.1.3: > $ Singular > SINGULAR / > Development > A Computer Algebra System for Polynomial Computations / version > 3-1-3 > 0< > by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann \ March > 2011 > FB Mathematik der Universitaet, D-67653 Kaiserslautern \ > // ** executing /SandBox/Justin/sb/Singular/3-1-3/LIB/.singularrc > > ring R=0,x,dp; > // ** redefining R ** > > poly f1=(1/2)+x; > > poly f2=1+2*x; > > f1/f2; > 1/2 > > FWIW. > > Justin > > -- > Justin C. Walker, Curmudgeon at Large > Institute for the Absorption of Federal Funds > ----------- > I want to die, peacefully in my sleep, like my grandfather; > not screaming in terror, like his passengers. > > > > > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
