On 3/13/07, Kostas Oikonomou <ko at research.att.com> wrote:
> Is there a way to write a double sum in Maxima? E.g.,
>
> sum_{1 <= i < j <= n} a[i] * b[j]
Unfortunately no. I would be very interested to have such a thing.
One solution is to allow something like sum(expr, i, S) where S is
a set, either explicit (like {a, b, c}) or implicit (like {(i, j) s.t.
1 <= i < j <= n}).
Maxima doesn't recognize implicit sets; I'd like to see that too.
There remains the problem of telling Maxima what to do with such
summations, but first we have pick a representation, and just that
would be a step in the right direction.
FWIW
Robert