Here is a sample problem description in YAML. It is complete in terms of the description but the problem is too simple to optimize anything.
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There are two hierarchies, one level each: [product] and [customer].
There are two spaces: ByProduct and ByProductAndCustomer. Each of them contains only the standard All scope.
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In ByProductAndCustomer, All scope, there are two variables: Volume and Turnover. Their values are different for each pair of (product x customer). Volumes are fixed, they are read from historical_volume data. Turnovers are computed. They are the product of a list price by volume for each pair of (product x customer), they change because of list prices changes.
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