Bugfix for GosperSum? (was: cannot load Zeilberger)



> >/ Blindly changing
> />/
> />/ if op(expr) = "+"  then
> />/
> />/ into
> />/
> />/ if op(expr) = "+"  or op(expr)="-" then
> /
> This alone is not enough. It still fails for -n*n!. 
Hmm true

> A better fix is
> probably to add another if statment:
>
> if op(expr)="-" then
>   return(shiftQuoAuxHypCheck(-expr, k, hyp_flag))
>   
You mean another else if? I still get

AntiDifference(-k*k!,k);
- k k!  is not hypergeometric in  k

Michel