I've opened https://sourceforge.net/p/maxima/bugs/4634/ for this, and hopefully we'll hear back. Can someone open a corresponding Sage ticket which will eventually get a doctest for the same? Thanks!
On Monday, November 17, 2025 at 10:38:54 PM UTC-5 Nils Bruin wrote: > I can confirm the behaviour you're observing ... It's really unfortunate!. > This would be a result produced by maxima, so most likely it's a change due > to a change in maxima version. I would call it a bug. One should probably > try to reproduce it in maxima proper and then report it to maxima. > Hopefully they can fix it. > > In maxima 5.47.0 I get: > > (%i1) load(simplify_sum)$ > (%i2) simplify_sum( sum(n*(-1)^n,n,1,inf)); > -1/4 > > This happens both on sage's ECL based one and on the system maxima > (running on SBCL). So I think this behaviour tracks decisively to maxima. > > On Monday, 17 November 2025 at 19:23:53 UTC-8 [email protected] wrote: > >> I have used SageMath within CoCalc for teaching Calculus 2 for several >> years. >> >> In past semesters, the following code produced the output "ind": >> >> var('n') >> sum(n*(-1)^n,n,1,oo) >> >> This is expected, since the series diverges. >> >> However, this semester I changed the kernel from SageMath 10.4 to the >> current SageMath 10.7. Now this same code produces the output "-1/4" [I >> believe 10.5 and 10.6 behave the same way as 10.7.] >> >> I have my students compute the value of several similar series (replacing >> the -1 in the code above with -2, -1/2, 1/2, 1, and 2), and all the others >> are behaving the same way they always have. It is only this series which is >> giving me an unexpected output. >> >> Has anyone else encountered this issue? >> >> Thanks, >> Aaron >> > -- 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 view this discussion visit https://groups.google.com/d/msgid/sage-support/25fe7afc-4c8d-4593-8cd0-c155d15556bfn%40googlegroups.com.
