The design of algorithmic classes follows one principle. An abstract base class is used to define an interface for an algorithmic problem (such as solving sparse linear systems of equations). Then (a number of) inherited classes provide (different) implementations for the interface. This design allows alogirthms solely using the interface class to work with any implementation class available for it, yielding a large variety of differing implementions. The algorithmic classes included in SoPlex are presented in the following subsections.