Using vectors in single NLP constraint inside proc iml with call statement

I have two variables that are stored in a data set and also are stored as matrices and vectors. I want to formulate only one constraint that is a function of all the data set's observations (or elements of these vectors) and a decision variable. Suppose the two stored variables (two vectors) are a

Questions about optmodel constraints

and b, and x is a decision variable and the scalar is c, I want c to appear as in the following constraint: sum over i for [ c*(ai)^2 * bi/ (ai+x)] = 0.5 , can you help me to do this under optmodel? Thanks Ayaa -- http://mail.python.org/mailman/listinfo/python-list