# sum(VisibleList,VisibleList,Function) -- sum results of applying a function pairwise

## Synopsis

• Function: sum

## Description

sum(v,w,f) yields the sum of the results obtained by applying f to each of the pairs (i,j) of elements from the lists or sequences v and w, which should be of the same length.

 i1 : R = ZZ[x,y,z]; i2 : sum({2,3,4},{x,y,z},(i,j)->j^i) 4 3 2 o2 = z + y + x o2 : R