Se u = z₁u₁ + z₂u₂ + … + z_su_s Î U, siano

G(u) = x₁v₁ + x₂v₂ + … + x_nv_n

F(G(u)) = (FG)(u) = y₁w₁ + y₂w₂ + …+ y_mw_m.

Ponendo

z = , x = , y = , si ha :

x = M_v,u(G)z

y = M_w,v(F)x = M_w,v(F)[M_v,u(G)z] = [M_w,v(F)M_v,u(G)]z.