The below is adapted from comments from Matt Kaufmann and J Strother Moore on
[PR #830][1].

---

The books in this directory (`books/workshop`) serve as an archive for the
supporting materials of their corresponding papers published at the ACL2
Workshop.  While they may depend on other community books, typically no other
books depend on them.

In consideration of the above, please don't make any changes to these workshop
books, unless one of the following applies:

- you have the permission of the original author of the book you want to change
  / the author of the associated ACL2 Workshop publication

- the original author cannot be easily contacted

- the change is necessary in order to fix a broken regression

Another option is to "fork" the book, i.e. make a copy of it elsewhere in the
repository (for example under `books/projects`, `books/tools`, or `books/std`)
and make your changes there.  If a workshop book is found to be useful as a
basis for other development, it would be good to proactively create such a fork
it even if you don't have any immediate changes to make, because that way people
can feel more comfortable using the fork in their own code, knowing that it can
be modified whenever necessary.

[1]: https://github.com/acl2/acl2/pull/830#issuecomment-375827341
