getCommand(delivery(item(model(1), name(book), brand(mitpress)), count(5), price(10))). getCommand(delivery(item(model(2), name(dvd), brand(sony)), count(15), price(50))). getCommand(inventory(model(_), name(_), brand(_), type(new))). getCommand(inventory(model(_), name(_), brand(_), type(open_box))). getCommand(order(customer(chris), item(model(1), name(_), brand(_)), count(2), max_price(12), type(_))). getCommand(order(customer(vladimir), item(model(1), name(book), brand(_)), count(7), max_price(9), type(new))). getCommand(sale(model(_),name(_), brand(_), percentage(40))). getCommand(order(customer(vladimir), item(model(1), name(book), brand(_)), count(7), max_price(9), type(_))). getCommand(order(customer(joe), item(model(2), name(dvd), brand(sony)), count(9), max_price(45), type(new))). getCommand(inventory(model(_), name(_), brand(_), type(_))). getCommand(return(customer(chris), item(model(1), name(_), brand(_)), count(1))). getCommand(return(customer(jimm), item(model(2), name(_), brand(_)), count(6))). getCommand(inventory(model(_), name(_), brand(_), type(new))). getCommand(inventory(model(_), name(_), brand(_), type(open_box))).