1. The problem statement, all variables and given/known data Use the formulas given (which have been solved in previous questions) prove that where w_12 is a complex constant. From here, induce that where eps_abc is the fully anti-symmetric symbol 2. Relevant equations The equations given to use are: 3. The attempt at a solution First, I expanded the commutator given (cannot give here as I have reached max file upload for a single post), but after that I keep on looking at it and I'm not exactly sure how to proceed. I have proved the first and last of the "relevant equations" and have the expanded forms of that and I think I may have to use that but I am not sure. Any help would be appreciated.