系统应实现的操作及其功能定义如下：

1）采编入库：新购入一种书，经分类和确定书号之后登记到图书账目中。如果这种书在账目中，则只将总库存量增加。

2）清除库存：某种书已无保留价值，将它从图书账目中注销。

3）借阅：如果某种书的库存量大于0，则借出一本，登记借阅者的图书证号和归还期限。

4）归还：注销对借阅者的登记，改变该书的现存量。

-system should achieve the operation and function are defined as follows : 1) The amount of editing : buy a new book, After classification and identification of the registered after ISBN books accounts. If this book in the accounts, will only increase the total inventory. 2) Elimination of stock : some had reservations book value of its accounts from the books that were written off. 3) Readers : If a certain amount of the stock is greater than 0, then lent a registered borrow the books permit number and the return period. 4) return : Readers write-off of the registration, change the existing volume of the book.