Dr.-Ing. Sudchai Boonto, KMUTT, 2013
Identify I
(I−XY)−1W=W+XY(I−XY)−1W
Proof
(I−XY)−1W=W−W+(I−XY)−1W=W+(−(I−XY)+I)(I−XY)−1W=W+XY(I−XY)−1W