Let K {\displaystyle {}K} be a field and let V {\displaystyle {}V} and W {\displaystyle {}W} be vector spaces over K {\displaystyle {}K} , where W {\displaystyle {}W} is finite-dimensional. Let
denote a linear mapping.
w 1 , … , w n ∈ W {\displaystyle {}w_{1},\ldots ,w_{n}\in W} and linear forms f 1 , … , f n {\displaystyle {}f_{1},\ldots ,f_{n}} on V {\displaystyle {}V} such that