On Thu, Jul 24, 2008 at 4:25 AM, William Stein <wstein at gmail.com> wrote:
> teragon-2:doc was$ sage -maxima
> Maxima 5.13.0 http://maxima.sourceforge.net
> (%i1) limit(floor(x),x,0,minus);
> (%o1) 0
> (%i4) limit(ceiling(x),x,0,plus);
> (%o4) 0
Well, that's obviously wrong. However in more recent versions
limit returns noun expressions for floor and ceiling.
That's not incorrect, but also not very helpful.
Obviously it is desirable to get correct results for discontinuous
functions. I'm not sure what is the best way to go about it.
It would be easy to wire in special cases for floor(x) and
ceiling(x), and that would help, but I don't know whether
Maxima can infer results for more complex cases from that.
Dan Gildea has been fixing a lot of bugs in the limit code
(thanks very much, Dan). Maybe he can comment on this.
FWIW
Robert Dodier