## #26 Hospital gives up without warning

closed
nobody
5
2009-03-18
2002-03-26
No

Behavior:

(C1) limit(exp(-1/x)/x^5,x,0,PLUS);

(D1)                                  0
(C2) limit(exp(-1/x)/x^6,x,0,PLUS);

- 1/x
%E
(D2)                           limit   -------
x -&gt; 0+    6
x
Explanation (Richard Fateman):

lhospitallim is set to 5. Yes it is arbitrary, but you
can change it.

Expected behavior:

Wouldn't it be nicer if there was some
warning message telling us &quot;I  stopped, but by
changing this variable you could maybe get me to
evaluate the  limit in full&quot;...? This gives the wrong
impression... like &quot;oh! Maxima can't solve that!&quot;.

I suppose this could be done, but it might also be
the case that after giving up on L'Hopital's rule it
tries something else that might succeed.  The
source code for limit is available.

I agree. It also might be a good idea to increase
the default value.
Computers are bigger and stronger now.

## Discussion

• Robert Dodier - 2006-03-26
• labels: --> 460522

• Robert Dodier - 2006-03-26

Logged In: YES
user_id=501686

For the record, same behavior in Maxima 5.9.3.

• Robert Dodier - 2006-06-26
• labels: 460522 --> Lisp Core - Limit

• Raymond Toy - 2006-11-09

Logged In: YES
user_id=28849

I think we should just increase the default to 8 (just as
arbitrary as 5) and close this bug.

Alternatively, we could make L'Hopital check to see if the
numerator or denominator is a polynomial and change the
limit appropriately.

• Dieter Kaiser - 2009-01-01

I can not read all of this bug report (a lot of unreadable ? chars in the text) but the examples seems to be:

(%i26) limit(exp(-1/x)/x^5,x,0,plus);
(%o26) 0
(%i27) limit(exp(-1/x)/x^6,x,0,plus);
(%o27) 0

Both limits work and seems to be right. The bug has gone.

I have set this bug report to pending.

Dieter Kaiser

• Dieter Kaiser - 2009-01-01
• status: open --> pending

• SourceForge Robot - 2009-03-18

This Tracker item was closed automatically by the system. It was
previously set to a Pending status, and the original submitter
did not respond within 14 days (the time period specified by

• SourceForge Robot - 2009-03-18
• status: pending --> closed