BOOK (acc_no, year, title)
USER (card_no, name, address)
SUPPLIER (s_name, address)
BORROWED_BY (acc_no, card_no, date of issue)
SUPPLIED_BY (acc_no, date of supply, price, s_name)
In the above relation, find out all the books which are either issued, or have been supplied by a supplier.
Give your answer in the following forms:
(a) Relational Algebra
(b) SQL
(c) Tuple Calculus