Identify Objects and classes and revise it to obtain a list of candidates.

I already extracted problem statement and identified and revised some of them but still don't see they are ok. Please verify, to add or delete it. Also specify each of object and class such as (attribute, role played, simple value, event, tangible thing, concept)

PROBLEM STATEMENT

You are asked to develop a library information system (LIS) for a public library. The LIS will be used to handle book loan and return procedures. A user can search books by title, ISBN, keyword or author with the LIS. The LIS will display all the titles that match the search. A book may have more than one edition and an edition may have more than one copy. The user can select a book to show the book information including book title, publisher, edition, ISBN, category and availability status.
Possible book availability statuses are "Checked in", "Checked out", "Hold" and "Overdue". In the case of "Checked out", the due date of the book is shown, whereas in the case of "Hold", the number of holds is shown. The user can place or cancel a hold on the book when the book record is shown and the book has been borrowed. A book is
removed from the LIS when it is discarded.

When a user borrows a book (check out), he/she has to scan the barcode of his/her library card at an LIS user terminal. The LIS will display his/her personal loan records that contain details like books borrowed, due date of return, as well as the total overdue fine, if any. If there is an outstanding fine, the LIS will not allow the user further loan. The user terminal will automatically print a charge notice. Users can settle fine payment at the library counter, which is handled by the library assistants with an LIS administrator terminal. If there is no outstanding fine, the LIS will check whether the user has exceeded
the loan limit. A user can borrow at most five books for one month. If the loan limit is not exceeded, the user can borrow a book by scanning the book barcode at an LIS user terminal. A new loan record is added to the user loan records. A receipt is then printed, indicating the book title, ISBN, publisher, author, date of loan and due date for return.
Books are returned through a collection box at the library entrance. Library assistants check in the returned books with the LIS administrator terminals. The system displays the book details and the due date of the book loan. If a book is returned late, an overdue fine is calculated and added to the borrower's fine record. Overdue fine is $1 per day. Once the book return is completed, the status of the corresponding book loan record is set to "returned". If the number of holds for the book is zero, the system updates the book record status to "checked in", otherwise the system updates book record status to "hold".

Identify objects and classes and revise it to obtain a list of candidates:

You are
Book (tangible thing)
Title (attribute)
ISBN (attribute)
Keywords (simple value)
Keywords of the book (simple value)
Author (attribute)
LIS-Library information system
Edition (attribute)
One copy(tangible thing)
User- covered by you are or borrower
Publisher (attribute)
Category (attribue)
Availability (attribute)
Book information (attribute)
Book availability status (simple value)
Overdue (attribute)
Due date
Case
Number
Book record
Barcode
Library card (simple value)
LIS user terminal
Personal loan records (concept)
Total overdue fine
Charge notice
Fine payment (concept)
Library counter
Library assistants (role played)
LIS administrator terminal (role played)
Most five books
One month
Loan limit
Book barcode
Collection box
Library entrance
Book details (attribute)
Book loan record (concept)
Returned late
Borrower's fine record (concept)
Over due fine $1 per day( simple value)
system
book record status
borrower(role played
checked out ( event)
checked in (event)

Revised list of candidate objects:
Borrower (role played)
Library assistants (role played)
LIS administrator terminal (role played)
Book (tangible thing)
checked out ( event)
checked in (event)
fine payment (concept)