Let K {\displaystyle {}K} denote a field and let I {\displaystyle {}I} denote a set. We consider the set of functions from I {\displaystyle {}I} to K {\displaystyle {}K} , that is
This set is with componentwise addition, where the sum of two functions f {\displaystyle {}f} and g {\displaystyle {}g} is given as
for z ∈ I {\displaystyle {}z\in I} , and with scalar multiplication defined by
a vector space.