Let U be the set of all linear transformations of V into W, and let O: V → W be the zero linear transformation defined by O(x) = 0W for all x in V.
(a) Prove that O ⊞ L = L E ⊞ 0 = L for any L in U.
(b) Show that if L is in U, then
L⊞ ((-l) ⊡ L) = O.