The following is part of a database for managing bookstore orders.

* The database includes the following relationships:

-> stores

stores (sid, s_name, address, tel_no), The relationship includes data about stores:

sid = Store ID/ s_name = store name/ address = store address/ tel_no = store phone number

* sid: relationship key

-> books

books(bid, title, author, subject, publisher, pub_date), The relationship includes data about books:

bid = Book ID (ISBN)/ title = book title/ author = author/ subject = book topic/ publisher = publisher/ pub_date = Issue date

* bid = relationship key

-> reservations

reservations (res_id, bid, sid, r_date, no_of_copies), The relationship includes data on book orders:

res_id = Order ID/ bid = book ID code/ sid = Store ID/ r_date = Order Date (day / month / year)/ no_of_copies = Number of copies ordered

*Relationship key: res_id

Formulate queries in the algebra that derive:

A. The names of all the stores that have ever ordered books from MASADA.

B. The names of the writers that no store ordered their book.