ILOG CPLEX offers you several ways to declare an SOS in a problem:
sos
. SOS files offer you the most powerful and flexible alternative because the SOS file structure allows you to do several tasks at once:
.mps
or in LP format with the file extension .lp
. If you already have MPS files with SOS information, you may prefer this option. Conventions for declaring SOS information in MPS files are documented in the ILOG CPLEX Reference Manual.