Summing problem



There was a discussion on the list on the way sum evaluates its arguments.
(although I found the discussion very enlightening, it seemed to be a bit
heated...)

It started approximately in point 4 of

http://www.ma.utexas.edu/pipermail/maxima/2002/003101.html

What I believe is the current state of the sum specific stuff appears in

http://www.ma.utexas.edu/pipermail/maxima/2002/003107.html

If I made a mistake, please tell me.

Martin