Help with matrix trace

Hi guys,

I need to prove that

thank you so much in advanced!

edit:
of course...

Well here you go, I hope it helps :D

Made an oopsie!

-Dan

Hmmm, me?
I guess I could use some () around my summations, but if I did make a fatal error, then I got temporarely blind. Would you mind pointing it out?

that is absolutley brilliant.
thank you so much, Zouzz. (Rock)