Comment by vrotaru

Good observation. Also there is some funny stuff with what the book say referenced appendices do and what those actually explain

At the end of chapter 30 we have:

   Next: Appendix A — OCaml Setup and Tooling

But the after the chapter 30, follows the chapter 31, and Appendix A is called

    Appendix A: Ocaml Quick Reference

And the link is a dead link.