help links subscribe changes refresh edit

	IssueTracker
#296 PERMGRP should compute cycle indicator polynomial ←	↑	→ #298 undesirable horizontal scroll bar

#297 Wrong values of limit

Edit detail for #297 Wrong values of limit revision 2 of 3

	1 2 3
Editor: test1 Time: 2015/10/13 11:42:37 GMT+0
Note:

changed:
-Yes, somebody should reorganize the limit package and implement Gruntz algorithm. This is on the WishList, by the way. I believe this is also related to asymptotic expansions as provided by Gdev from Maple, but I'm not sure.
Yes, somebody should reorganize the limit package and implement Gruntz algorithm. This is on the OldWishList, by the way. I believe this is also related to asymptotic expansions as provided by Gdev from Maple, but I'm not sure.

For the following limit:

fricas

limit(exp(exp(2*log(x^5+x)*log(log(x))))/exp(exp(10*log(x)*log(log(x)))), x = %plusInfinity)

$\label{eq1}+ \infty$

(1)

Type: Union(OrderedCompletion?(Expression(Integer)),...)

the correct answer is +infinity. Simpler version is:

fricas

limit(exp(2*log(x^5+x)*log(log(x)))-exp(10*log(x)*log(log(x))), x = %plusInfinity)

$\label{eq2}+ \infty$

(2)

Type: Union(OrderedCompletion?(Expression(Integer)),...)

(again the correct answer is +infinity).

Another problematic limit is:

fricas

limit(max(x, exp(x))/log(min(exp(-x), exp(-exp(x)))), x = %plusInfinity)

   There are 1 exposed and 2 unexposed library operations named max 
      having 2 argument(s) but none was determined to be applicable. 
      Use HyperDoc Browse, or issue
                               )display op max
      to learn more about the available operations. Perhaps 
      package-calling the operation or using coercions on the arguments
      will allow you to apply the operation.

   Cannot find a definition or applicable library operation named max 
      with argument type(s) 
                                 Variable(x)
                             Expression(Integer)

      Perhaps you should use "@" to indicate the required return type, 
      or "$" to specify which version of the function you need.

where the correct answer is -1.

BTW both examples are taken from Dominik Gruntz thesis form 1996

Waldek Hebisch

... --kratt6, Mon, 05 Jun 2006 02:10:40 -0500 reply

Yes, somebody should reorganize the limit package and implement Gruntz algorithm. This is on the OldWishList?, by the way. I believe this is also related to asymptotic expansions as provided by Gdev from Maple, but I'm not sure.

Could you do this?

Martin