 Relational Model slides for Database System Concepts by Abraham Silberschatz and others

Primary source: www.db-book.com/Previous-editions/db4/slide-dir/ch3-2.pdf

Verified locator: Fourth-edition slides3.82 and3.86, Safety of Expressions; author page www.db-book.com/Previous-editions/db4/overview.html verifies Abraham Silberschatz, Henry F. Korth and S. Sudarshan.