Thanks for the hint, i am running it right now.  Actually, not only gamma is a constant, all the variables with index 2 are constant.  I solve for xi and the variables with index 1.  Since i solve these exautions iterativally, i can pick one of those 6 variables, leaving a 5*5 system to solve.  The reason why i pick rho_1 as being constant, and thus iterationg on it, is physical, it really is the only possibility.  Therefore, i solve the system that i posted.  I will keep you informed.  Could you send the complete solution you got to me?

thanks,

peter