Could you help me prove the attached equation? It is from Knuth TAOCP vol. 4A, the author says the left hand reduces to right hand, but does not show how. Maybe it is easy, but I could not solve it (I am not good at formulas).
Edited to add: SOLVED. I looked in volume 1 of TAOCP, there are two important formulas to be used to prove the above equation.