The price of each item in a store is non-negative. The store manager is only interested in rules of certain forms, using the constraints given in (a)-(b). For each of the following cases, identify the kinds of constraints they represent and briefly discuss how to mine such association rules using constraint-based pattern mining.
(a) Containing at least one Blu-ray DVD movie.
(b) Containing items with a sum of the prices that is less than $150.
(c) Containing one free item and other items with a sum of the prices that is at least $200.
(d) Where the average price of all the items is between $100 and $500.