Objective function used to solve for p lambda parameters. The objective function involves p simultaneous equations corresponding to p covariates used in the model. Let tilde cap T sub x denote the control total for covariate x, and the adjusted weight for person k is obtained by taking the product of the original design weight and the adjustment factor a sub k of lambda. Then the objective function equation for covariate x is defined as the sample-weighted (using adjusted weight) sum of covariate x equal to the control total for covariate x.