Implementing a specific nonlinear solver interface via mmnl

The Mosel module mmnl that provides handling of nonlinear expressions and constraints for the Mosel language also publishes a library interface in the Mosel NI format that makes it possible to implement specific DSO (such as mmxnlp in the Xpress distribution) for interfacing directly to solvers for nonlinear programming problems.

The example implementation discussed in the following section shows how to use the nonlinear problem handling functionality for the special case of a quadratic solver. The relevant functions of the mmnl inter-module interface are documented in Section NI library interface functions of mmnl.