I get results that make sense when the are no assumptions and the limit noun form when there are. The limit noun form makes some
sense to me since it I think it is used to mean that limit cannot do this case. Also no packages were loaded at the time when I was
trying this.
(%i1) assume(x<-2);
(%o1) [x < - 2]
(%i2) limit(floor(x),x,0);
(%o2) limit floor(x)
x -> 0
(%i3) limit(floor(x),x,0,'plus);
(%o3) limit floor(x)
x -> 0+
(%i4) limit(floor(x),x,0,'minus);
(%o4) limit floor(x)
x -> 0-
(%i5) forget(x<-2);
(%o5) [x < - 2]
(%i6) limit(floor(x),x,0);
(%o6) und
(%i7) limit(floor(x),x,0,'plus);
(%o7) 0
(%i8) limit(floor(x),x,0,'minus);
(%o8) - 1
Rich
----- Original Message -----
From: "Karl-Dieter Crisman" <kcrisman at gmail.com>
To: <maxima at math.utexas.edu>
Sent: Thursday, October 01, 2009 1:49 PM
Subject: Limit and assumptions
Dear list,
I realize I wasn't clear before. My question is which one is supposed
to happen below for the limit of floor(x), under the assumption given.
Apparently it has something to do with the assumption, since it
"works" for variable y.
1) Returns und (similarly to how limit(x^2) and limit(sin(1/x)) return
the "correct" value)
2) Returns just limit, as below (in which case perhaps other limits at
x=0 should also just return the limit again)
3) Raises an error (in which case all of them should).
Thank you for any clarification! I am happy to report this as a bug,
but I don't know whether it is considered to be one, or which of 1)-3)
it is (hence, which line below IS the bug).
Maxima 5.19.1 http://maxima.sourceforge.net
Using Lisp SBCL 1.0.30
Distributed under the GNU Public License.
See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) assume(x<-2);
(%o1) [x < - 2]
(%i2) limit(floor(y),y,0);
(%o2) und
(%i3) limit(x^2,x,0);
(%o3) 0
(%i4) limit(floor(x),x,0);
(%o4) limit floor(x)
x -> 0
(%i5) limit(sin(x)/x,x,0);
(%o5) 1
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