[Maxima] I cannot load zeilberger package |||| nusum & Zeilberger

[Michel Van den Bergh]

I wrote
> Don't forget that GosperSum included with Zeilberger has some bad bugs. Try
>
>  GosperSum(-1/(n*(n+1)),n,1,k);
>
> and
>
>  GosperSum(1/(n*(n+1)),n,1,k);

This bug is probably easy to fix. The error message comes form
the fuction shiftQuoHypCheckAux in the file
zeilberger/shiftQuotient.mac. This checks for
all possible operators in a certain expression and does something. It
checks for "+"
but forgets to check for "-". Somebody who is slightly familiar with the
Gosper algorithm can
probably figure out how to correct this.

Michel