Create the conceptual design and database schema for a library system. (this exercise is only addressing a small part of a real library system). patrons (customers) borrow books from the library. all books have an isbn number that identifies the book unique. for each book, the system must store isbn, author name, current status (on-loan, or available) library must keep patron identification as well as contact information. it is safe to assume that the library assigns a library card with an identification number. the library also keeps track of the number of books on loan to a customer, as well as the outstanding fines (dollars and cents) due from the customer.