I want to sum over several variables at once.
For example, something like
sums over 3 variables. But this can only be done if I know the number of variables in advance. I want to write a code that will sum over m variables, with m being supplied on demand.
Maple can do this for integrals. If I write
the integral is computed over m variables, for any m.
How can something like this be implemented for summation?