The software system allows to solve constrained nonlinear programming problems by an efficient sequential quadratic programming (SQP) method. A nonlinear objective function is to be minimized subject to nonlinear equality or inequality constraints. The numerical code is called NLPQL, which is frequently used in industry and academia. The mathematical method represents the scientific state-of-the-art.
Model functions are defined in a modeling language called PCOMP and are interpreted and evaluated during runtime. It is assumed that all nonlinear functions are differentiable. Gradients are computed automatically. EASY-OPT Express is particularly useful for classroom exercises of optimization courses or to become familiar with optimization routines before starting a real life implementation. The mathematical theory of the algorithm is described in the documentation and the usage of the system is outlined in detail.