cSupply[i].setUB((x[i] >= 0.5) ? capacity[i] : 0);
}
// solve the subproblem
sub.solve();
IloCplex.Status status = sub.getStatus();
IloNumExpr expr = master.numExpr();
if (status == IloCplex.Status.Infeasible) {
// subproblem is infeasible -- add a feasibility cut
// first step: get a Farkas certificate, corresponding to a dual ray
// along which the dual is unbounded
IloConstraint[] constraints = new IloConstraint[nWarehouses + nCustomers];