On 7/26/09, Richard Fateman <fateman at cs.berkeley.edu> wrote:
> 1. Sumhack is a respectable and useful feature.
OK, I'm jumping on the bandwagon. Sumhack is fine by me.
> Incidentally, I put sumhack into Macsyma, 35-40 years ago.
> I hadn't heard that it was removed from Maxima.
Yeah. I cut it out in a wider revision of the summation code in
Nov 2005. I;m pretty sure I got the idea from else (i.e. don;t
blame me, or don't blame only me, anyway).
Aside from sumhack. sum tried to treat the index as a local variable,
and I tried pretty hard to preserve that and make it work "better".
At this point, however, it seems clear that the funny evaluation
policy for sum causes more confusion than it's worth.
I wish I had made sum an ordinary function when I had the chance.
It's not too late, someone else can give it a try this time.
FWIW
Robert Dodier