I think we have some problems with the limit of the logarithm function.
No problem with inf:
(%i3) limit(log(x),x,inf);
(%o3) inf
For minf Maxima returns an expression with an infinity in it.
(%i4) limit(log(x),x,minf);
(%o4) inf+%i*%pi
Interesting is the answer for infinity. The limit from both sides does
not work.
(%i5) limit(log(x),x,infinity);
sign: sign of infinity is undefined.
-- an error. To debug this try debugmode(true);
And we get different answers for the limit from above and below.
(%i6) limit(log(x),x,infinity,plus);
(%o6) infinity
(%i7) limit(log(x),x,infinity,minus);
(%o7) infinity+%i*%pi
Furthermore the limit for ind is not simplified.
(%i8) limit(log(x),x,ind);
(%o8) log(ind)
The limit for und has no problem.
(%i9) limit(log(x),x,und);
(%o9) und
I think the code of simplimln has been designed to give the following
answers:
limit(log(x),x,minf) -> infinity
limit(log(x),x,infinity -> infinity
limit(log(x),x,ind) -> und
It is possible to change simplimln to get these answers.
I had a look at wolfram.functions.com. There the following definitions
for the limits are given:
limit(log(x),x,minf) -> inf
limit(log(x),x,infinity) -> inf
Dieter Kaiser