This needs to be done in prolong. Solve it ASAP.

Tasks: 1. Write a rule item_quantity/2 that is used to find the inventory level of a named item. This shields the user of this predicate from having to deal with the item numbers. 2. Write a predicate valid_order/3 that checks whether a customer order is valid. The arguments should be customer, item, and quantity. The predicate should succeed only if the customer is a valid customer with a good credit rating, the item is in stock, and the quantity ordered is less than the quantity in stock