def METHOD_NAME(model):
    production_costs = sum([model.SetupCosts[i] * model.ProduceSizeFirstStage[i] + \
                           model.UnitProductionCosts[i] * model.NumProducedFirstStage[i] \
                           for i in model.ProductSizes])
    cut_costs = sum([model.UnitReductionCost * model.NumUnitsCutFirstStage[i,j] \
                    for (i,j) in model.NumUnitsCutDomain if i != j])
    return (model.FirstStageCost - production_costs - cut_costs) == 0.0