Bugfix for GosperSum? (was: cannot load Zeilberger)
Subject: Bugfix for GosperSum? (was: cannot load Zeilberger)
From: Andrej Vodopivec
Date: Sat, 6 Jan 2007 22:34:50 +0100
On 1/6/07, Michel Van den Bergh <michel.vandenbergh at uhasselt.be> wrote:
>
> > >/ 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
Yes, another else if. The correct result is -k!.
Andrej