The following tables form part of a Library database held in an RDBMS:

• Book (ISBN, title, edition, year)

• BookCopy (copyNo, ISBN, available)

• Borrower (borrowerNo, borrowerName, borrowerAddress)

• BookLoan (copyNo, dateOut, dateDue, borrowerNo)

where:

• Book contains details of book titles in the library and the ISBN is the key.

• BookCopy contains details of the individual copies of books in the library and copyNo is the key. ISBN is a foreign key identifying the book title.

• Borrower contains details of library members who can borrow books and borrowerNo is the key.

• BookLoan contains details of the book copies that are borrowed by library members and copyNo/dateOut forms the key. borrowerNo is a foreign key identifying the borrower.

Formulate the following query in relational algebra

5.33 How many times has the book title with ISBN 0-321-52306-7 been borrowed?