This is the “academic” part of the book. By that, I mean that it has a style more like other textbooks; it is not motivated directly by a project. In a sense, I wish this part were not necessary. However, the material in this part did not fit easily into the project-oriented framework of the rest of the book. Furthermore, much of the material in this part is presented quite differently from anything you will find in other books.
There are many theorems stated, some with and some without proof. The proofs that are included are present because it was thought they would be somehow instructive, usually because they illustrate some typical calculations that you might find yourself making in daily practice. Other proofs are omitted completely or only sketched, because the full proofs are rather involved and not particularly helpful to a practicing engineer. However, an understanding of the flavor of a proof is sometimes helpful, even if the full proof is too complicated to present.
In most cases, it is possible to skip over the proofs that are present without missing any essential material. The beginning and ending of each proof is clearly marked. However, the proofs are not difficult, and any effort put forth in reading them will be repaid with a better understanding of the notation and of how computations can be done efficiently.
You can use the material in this part as reference material for the rest of the book, or you may decide to read straight through. ...