Publisher (name, phone, address), PK: name.

Book (ISBN, title, year, published_by, previous_edition), PK: ISBN, FK: published_by refs Publisher, previous_edition refs Book.

Author (SSN, first_name, last_name, address, income), PK: SSN.

Write(aSSN, bISBN), PK: (aSSN, bISBN), FK: aSSN refs Author, bISBN refs Book.

Author_Editor(aeSSN, works_for), PK: aeSSN, FK: aeSSN refs Author, works_for refs Publisher.

Give relational algebraic expressions for the following plain English language queries based on the above schema.

1. Provide the SSN of those authors who have coauthored all the books written by Andy Smith. (10 pts)

2.Provide the ISBN of every book whose publisher is different from the publisher of its previous edition. (10 pts)