\cdbalgorithm{list\_sum}{}

In an expression containing sums of identical-length lists, create one
new list constructed by adding the elements at the same position in
each list. Example,
\begin{screen}{1,2,3}
{a, b, 7 c + q, d, e} - {-f, g, h, i, j}:
@list_sum!(%):
@sumflatten!(%);
\{ a + f, b - g, 7c + q - h, d - i, e - j \};
\end{screen}
To generate a list of the products of the elements,
use \subscommand{inner} instead.

\cdbseealgo{inner}
\cdbseealgo{range}
