... But few instructors are likely to enjoy such a luxury. One point instructors need to be aware of: Exercise 4 .1 introduces the extended version of the running suppliers-and-parts example ... 4 .11 WITH extensions, which are also intended to address this kind of problem. (See the short paper "The Importance of Closure" in my book Relational Database Writings 19 9 1- 1 994, ... suppliers-and-parts example (viz., suppliers, parts, and projects). Subsequent chapters tend to use suppliers-and-parts as a basis for the main body of the text and suppliers, parts, and projects as a basis...