Agricultural Pricing: What Prices to Charge for Dairy Products

The following constraints are used in this example:

bounds on variables
for $i \in \text {PRODUCTS}$ ,

$\frac{\Variable{Demand[i]} - \Argument{prev\_ demand[i]}}{\Argument{prev\_ demand[i]}} = \sum _{j \in \text {PRODUCTS}} \Argument{elasticity[i,j]} \cdot \frac{\Variable{Price[j]} - \Argument{prev\_ price[j]}}{\Argument{prev\_ price[j]}}$
for $\text {raw} \in \text {RAWS such that } \Argument{supply[raw]} \text { is not missing}$ ,

$\sum _{\text {product} \in \text {PRODUCTS}} \frac{\Argument{percent[product,raw]}}{100} \cdot \Variable{Demand[product]} \le \Argument{supply[raw]}$
$\displaystyle { \begin{aligned} [t] & \sum _{\text {product} \in \text {PRODUCTS}} \Argument{prev\_ demand[product]} \cdot \Variable{Price[product]} \\ \le & \sum _{\text {product} \in \text {PRODUCTS}} \Argument{prev\_ demand[product]} \cdot \Argument{prev\_ price[product]} \end{aligned} }$