On Thursday, April 14, 2016 at 1:52:37 AM UTC-7, Jeroen Demeyer wrote: > > I like it exactly the way it is. If you explicitly ask for a polynomial > over a polynomial, this is the expected answer. > It is at odds with the behaviour for multivariate polynomials, though.
The other surprising part is that one ends up in the situation where both ZZ['a'] and ZZ['a']['b'] have a conversion into ZZ['b']['a'], but the second conversion map does not extend the first one: sage: R=ZZ['a']['b'] sage: S=ZZ['b']['a'] sage: aR=R.base().0 sage: bR=R.0 sage: aS=S.0 sage: bS=S.base().0 sage: S(aR) a sage: S(bR) a sage: S(aR+bR-bR) b That's a horrible trap. (luckily, coercion doesn't use these maps. Then this behaviour would really be a bug) -- 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 https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
