What is Mosel?

Mosel is an environment for modeling and solving problems. To this aim, it provides a language that is both a modeling and a programming language. The originality of the Mosel language is that there is no separation between a modeling statement (e.g. declaring a decision variable or expressing a constraint) and a procedure that actually solves the problem (e.g. call to an optimizing command). Thanks to this synergy, one can program a complex solution algorithm by combining modeling and solving statements.

Each category of problem comes with its own particular types of variables and constraints and a single kind of solver cannot be efficient in all cases. To take this into account, the Mosel system does not integrate any solver by default but offers a dynamic interface to external solvers provided as modules. Each solver module comes with its own set of procedures and functions that directly extends the vocabulary and capabilities of the Mosel language. The link between Mosel and a solving module is achieved at the memory level and does not require any modification of the core system.

This open architecture can also be used as a means to connect Mosel to other software. For instance, a module could define the functionality required to communicate with a specific database.

The modeling and solving tasks are usually not the only operations performed by a software application. This is why the Mosel environment is provided either in the form of libraries or as a standalone program.