The purpose of this part of the book is to explain basic temporal database principles—i.e., the basic concepts and fundamental theory underlying temporal data and temporal databases. It consists of the following chapters (which, as stated in the preface, are definitely meant to be read in sequence as written):
8. The EXPAND and COLLAPSE Operators
9. The PACK and UNPACK Operators I: The Single-Attribute Case
10. The PACK and UNPACK Operators II: The Multiattribute Case
The titles give some idea as to the scope of each chapter. Further specifics are given near the end of the section “Temporal Databases” in Chapter 4.