############### ARBITRARY NETWORK POOLING PROBLEM INSTANCES ####################
These pooling problem instances are used in the experiments section of the paper 
by Alfaki and Haugland (2013). All the instances and the formulations have been 
written in GAMS.

HOW TO RUN THE TEST INSTANCES:
    I. SYSTEM REQUIREMENT:
        1. Windows/Unix.
        2. GAMS modeling system
        3. Global NLP solver (e.g., BARON).
   II. RUN AN INSTANCE:
        1. The default NLP solver is BARON, you can change it in one of the 
           formulation files; pmodel.gms, hybmodel.gms and mcfmodel.gms.
        2. Write the name of the formulation that you want to use in the first
           line of the file 'xmodel.gms' e.g., if the formulation you want to 
           use is MCF-formulation, then the first line of 'xmodel.gms' will 
           look like:

           $include mcfmodel.gms

        3. Suppose you want solve instance gppL1, so in the terminal (windows 
           command prompt) write:
           [pooling_instance_DIR]$ gams gppL1.gms 

Alfaki, M., and Haugland, D. (2013). A multi-commodity flow formulation for the 
generalized pooling problem. Journal of Global Optimization, 56(3): 917-937.
doi: 10.1007/s10898-012-9890-7.
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