Is it right to call a chapter of a book an "appendix"?
In *Think Python, 2nd Edition* the author states at the beginning of *Chapter 21. Analysis of Algorithms*: **"This appendix is an edited excerpt from ink Complexity, by Allen B. Downey, also published by O’Reilly Media (2012). When you are done with this book, you might want to move on to that one."**The online version of *Cambridge Dictionary* defines *"appendix"* as **"a separate part at the end of a book or magazine that gives extra information."**So I think that this chapter is a part of the the book, and not *"separate"* from it, but I may be getting something wrong. So, Is the author right or wrong? Why and why not? Thanks in advance.