It depends on exactly what you mean by undecidable, but this is the definition of an inexact ring in some sense. So, p-adics, power series rings, reals.... David
On Fri, Jul 17, 2015 at 1:34 AM, Volker Braun <vbraun.n...@gmail.com> wrote: > On Friday, July 17, 2015 at 10:25:29 AM UTC+2, Ralf Stephan wrote: >> >> 1. Can you come up with a Sage parent (other than SR) where >> element.is_zero() is sometimes undecidable? > > > The obvious example would be group rings. The word problem is undecidable so > you may not be able to figure out whether f-g==0 > > > -- > 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 post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- 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 post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
