Here we use the following notations:

• MD — meals and drinks;
• DBMD — database of MD;
• AG — alternative groups of MD;
• NG — a non-alternative such group.

     Given:

• amount of money, allocated to pay for the order at a restaurant;
• parameters a and b for calculating the cost of serving a customer y = a + b*x, where x — cost of acquired MD;

Note. The order cost consists of two parts: 1) cost of MD, selected by the customer, and 2) cost of serving him.

• possible sign of restricting a calorific value of the order;
• one of two possible criteria of usefulness of selected MD samples:
  • utility ratio for a MD sample (relative criterion);
  • consumer worth of a sample, that is equal to the product of its utility ratio by its cost (absolute criterion);
• selected DBMD of the restaurant, containing a list of available for acquisition MD, divided into several categories according to the restaurant menu. For each MD there are specified:
  • name and description of a MD sample (including its calorific value);
  • its cost;
  • list of possible additives thereto;
• formed by a customer several AG for MD, selected by him, and one NG;
• for each selected MD are given:
  • a value of criterion of its sample usefulness;
  • in the presence of its additives — signs of selecting the required ones;
• for each AG are set the minimum and maximum numbers of acquired samples of various MD, included in this group;
• for each MD of a single NG are set the minimum and maximum numbers of its acquired samples.

     Maximized quality criterion: total consumer worth of acquired MD under given restriction on cost of the order and under possible restriction on its calorific value.