simplification (or not) of summation to literal sum
Subject: simplification (or not) of summation to literal sum
From: Robert Dodier
Date: Sat, 21 Jul 2007 20:41:57 -0600
Hello,
At present when the difference between the bounds of a
summation is an integer, the summation simplifies to a
literal sum. E.g. 'sum(a[i], i, 1, 3) => a[1] + a[2] + a[3].
That is a change introduced (unintentionally) by the revision
of sum simplification which I made in December 2005.
Before that, a summation simplified to a literal sum when
the difference of bounds was an integer, and the simpsum
flag was present. E.g. 'sum(a[i], i, 1, 3) => 'sum(a[i], i, 1, 3)
but 'sum(a[i], i, 1, 3), simpsum => a[1] + a[2] + a[3].
I would like to change it back to the old way because there
are problems for which it makes sense to construct and
manipulate a definite summation without expanding it to a literal sum.
I wonder if there is any opposition to this proposal.
best
Robert