HI, I think it is related with ticket #17638 <https://trac.sagemath.org/ticket/17638>. There is a mathematical origin in this situation. When considering a non local ordering, one is working in a localized ideal, where any polynomial whose leading term is a non-zero constant is invertible. Singular works silently in this new ring without explicit declaration. I think that for Sage, a new structure should be constructed, but I do not know how. Best, Enrique.
El lunes, 6 de abril de 2020, 9:46:26 (UTC+2), Yang Zhou escribió: > > Hi, > > I am trying to truncate a multi-variable polynomial by moding out higher > order term and found > the following (simplified) example. I am wondering if it is a bug. > > > *Reproducible Example: * > >> R.<x,y> = PolynomialRing(QQ, order='negdeglex') >> > f = 1 + x >> I = R.ideal(x^2) >> f.mod(I) >> > *Expected output:* > >> 1 + x >> > *Actual output:* > >> 1 >> > > > *Note: * > The actual output will be 1+x when I omit the "order='negdeglex" parameter. > > *SageMath version:* > SageMath version 9.0, Release Date: 2020-01-01 > > *Operating system:* > OS: Ubuntu 19.10 x86_64 > Kernel: 5.3.0-45-generic > > Best regards, > Yang > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/593546a3-8c04-471f-a78f-3ff9400e9b03%40googlegroups.com.
