2.1 GAMS

GAMS is a general algebraic modeling system, based on its high level modeling language. It declares a model by specifying a number of Sets, Parameters, Tables, Scalars, Variables, Equations, Model. It contains a Solve statement to call a solver and various Display functions to output the results. GAMS has probably the largest number of interfaces to all kinds of solvers. Very large models can be processed efficiently using GAMS and it has a powerful sparse-indexing mechanism. A large number of model examples is available on the site of GAMS. GAMS is probably the oldest algebraic modeling language, its first version has been published in 1982. It is a commercial software, but a free demo version is available. As a small example, the following model implements the problem of maximally coexisting queens on a chessboard.

   2.1.1 Coexisting Armies of Queens (coexx)