An example is a promise kept small. It shows, in the least space it can, exactly what a larger thing would do, so that anyone can check their understanding before committing to the real work.

A good example hides nothing. It states its shape, its size, and its intent, and it behaves the same way every time you open it. That reliability is the whole point: you are testing your tools against a known quantity, not a mystery.

Every file format is a small agreement about where things go. Some keep their text in plain view; others fold it into compressed containers or binary tables. None of that changes the words a reader finally sees.

This book is one such agreement. It is a package of chapters, a stylesheet, a cover, and a table of contents, zipped together and labelled so a reader knows what to do with each part. Take it apart and you will find nothing surprising inside — only the pieces named in its manifest.

You are free to use this file for any purpose: to test a reader, a converter, or a parser, or simply to confirm that a chapter renders the way you expected.

When you are done, you will know a little more about how e-books are built, and you will have a dependable fixture to return to. That is all an example ever hopes to be.