Maxima Function
lsum (expr, x, L)
Represents the sum of expr for each element x in L.
A noun form 'lsum
is returned
if the argument L does not evaluate to a list.
Examples:
(%i1) lsum (x^i, i, [1, 2, 7]); 7 2 (%o1) x + x + x (%i2) lsum (i^2, i, rootsof (x^3 - 1)); ==== \ 2 (%o2) > i / ==== 3 i in rootsof(x - 1)