anchor.diff:  
   .example.adoc
   [source,asciidoc]
  -----
  +....
   = Document Title
   Doc Writer <doc@example.com>
   :doctype: book
  
positive.code: 
  == Prerequisites
  
  All that's needed is Ruby 1.9.3 or better and a few RubyGems, which we explain how to install in the next section.
  
  To check you have Ruby available, use the +ruby+ command to query the version installed:
  
  
negative.code: 
  If you want to clone the git repository, simply copy the {project-repo-uri}[GitHub repository URL] and pass it to +git clone+ command:
  
   $ git clone https://github.com/asciidoctor/asciidoctor-pdf
  
  Next, change to the project directory:
  
  