<li>To add to or improve this FAQ, [fork](https://help.github.com/articles/fork-a-repo/) the [antlr/antlr4 repo](https://github.com/antlr/antlr4) then update this `doc/index.md` or file(s) in that directory. Submit a [pull request](https://help.github.com/articles/creating-a-pull-request/) to get your changes incorporated into the main repository. Do not mix code and FAQ updates in the sample pull request. **You must sign the contributors.txt certificate of origin with your pull request if you've not done so before.**</li>
<li>This text was copied with permission from the [The Definitive ANTLR 4 Reference](http://pragprog.com/book/tpantlr2/the-definitive-antlr-4-reference), though it is being morphed over time as the tool changes.</li>
</ul>
Links in the documentation refer to various sections of the book but have been redirected to the general book page on the publisher's site. There are two excerpts on the publisher's website that might be useful to you without having to purchase the book: [Let's get Meta](http://media.pragprog.com/titles/tpantlr2/picture.pdf) and [Building a Translator with a Listener](http://media.pragprog.com/titles/tpantlr2/listener.pdf). You should also consider reading the following books (the vid describes the reference book):
This documentation is a reference and summarizes grammar syntax and the key semantics of ANTLR grammars. The source code for all examples in the book, not just this chapter, are free at the publisher's website. The following video is a general tour of ANTLR 4 and includes a description of how to use parse tree listeners to process Java files easily:
