starange "limit" behaviour



Probably the program is described in Paul Wang's
MIT PhD thesis.  sheur0 is probably "s" heuristic "0".

This problem is solved by the commercial Macsyma
correctly.

Raymond Toy wrote:

>>>>>>"Jaroslaw" == aw Piskorski <Jaros> writes:
> 
> 
>     Jaroslaw> Hi all!
>     Jaroslaw> Maxima seems to be unable to calculate the following limit with the "limit"
>     Jaroslaw> function
> 
>     Jaroslaw> limit(7^n/8^n,n,inf);
> 
>     Jaroslaw> and returns the limit unevaluated.
> 
> FWIW, I trace through a bit of the LIMIT function in src/limit.lisp.
> The bottom line is that maxima doesn't know how to compute the limit
> of things like that.  
> 
> For those interested, here is what happens. LIMIT calls LIMIT2 which
> seems to be designed to evaluate limits of ratios.  LIMIT2 calls
> SHEUR0 (what does that mean?) which calls CPA (what does that mean).
> CPA finally decides that because the numerator and the denominator are
> exponential forms, it gives up.  This causes LIMIT to give up.
> 
> I suppose maxima could be taught to handle this particular case.
> 
> Ray
> 
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