Another optional file format is BAS. Unlike the LP and MPS formats, this format is not used to store a description of the problem statement. Rather, it is used to store information about the solution to a problem, information known as a basis. Even after changes are made to the problem, using a prior basis to start the optimization from an advanced basis can speed solution time considerably. A basis can be written only after a problem has been solved. Try this now with the following command:

In response, ILOG CPLEX displays a confirmation message, like this:

Basis written to file 'example.bas'.