anchor.diff:  
    $ bundle
   
  -=== Yum (Fedora 18 or greater)
  -
  -Open a terminal and type:
  +To upgrade the gem, set the new version in the Gemfile and run `bundle` again.
  +Using `bundle update` is not recommended as it will also update other gems, which may not be the desired result.
  +
  +=== (c) Linux package managers
  +
  +==== Yum (Fedora 18 or greater)
  +
  +To install the gem on Fedora 18 or greater using yum, open a terminal and type:
   
    $ sudo yum install -y rubygem-asciidoctor
   
  -=== apt-get (Debian Sid, Ubuntu Saucy or greater)
  -
  -Open a terminal and type:
  +To upgrade the gem, use:
  +
  + $ sudo yum update -y rubygem-asciidoctor
  +
  +TIP: Your Fedora system may be configured to automatically update packages, in which case no action is required by you to update the gem.
  +
  +==== apt-get (Debian Sid, Ubuntu Saucy or greater)
  +
  +To install the gem on Debian or Ubuntu, open a terminal and type:
   
    $ sudo apt-get install -y asciidoctor
  +
  +To upgrade the gem, use:
  +
  + $ sudo apt-get upgrade -y asciidoctor
  +
  +TIP: Your Debian or Ubuntu system may be configured to automatically update packages, in which case no action is required by you to update the gem.
   
   === Other installation options
   
   * {install-doc-uri}[Installing the Asciidoctor toolchain]
   * {install-osx-doc-uri}[Installing Asciidoctor on Mac OS X]
   
  -=== Upgrading
  -
  -If you have an earlier version of Asciidoctor installed, you can update it using:
  -
  - $ gem update asciidoctor
  -
  -[TIP]
  ---
  -If you install a new version of the gem using `gem install` instead of `gem update`, then you'll have multiple versions installed.
  -If you wish to remove older versions, use the following `gem` command:
  -
  - $ gem cleanup asciidoctor
  ---
  -
  -On Fedora, you can update it using:
  -
  - $ sudo yum update -y rubygem-asciidoctor
  -
  -TIP: Your Fedora system may be configured to automatically update packages, in which case no further action is required by you.
  -Refer to the https://docs.fedoraproject.org[Fedora docs] if you are unsure.
  -
  -On Debian or Ubuntu, you can update it using:
  -
  - $ sudo apt-get upgrade -y asciidoctor
  -
   == Usage
   
   If the Asciidoctor gem installed successfully, the `asciidoctor` command line interface (CLI) will be available on your PATH.
  
positive.code: 
  You should see information about the Asciidoctor version and your Ruby environment printed in the terminal.
  
    Asciidoctor 1.5.0.dev [http://asciidoctor.org]
    Runtime Environment (ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-linux])
  
  Asciidoctor also provides an API.
  
negative.code: 
  == The Big Picture
  
  Asciidoctor reads content written in plain text, as shown in the panel on the left in the image below, and converts it to HTML5, as shown rendered in the right panel.
  Asciidoctor adds a default stylesheet to the HTML5 document, as shown, to provide a pleasant out-of-the-box experience.
  
  image::{screenshot-img}[Preview of AsciiDoc source and corresponding rendered HTML]
  
  == AsciiDoc Processing
  
  Asciidoctor reads and parses text written in the AsciiDoc syntax, then feeds the parse tree into a set of built-in templates to produce HTML5, DocBook 5 (or 4.5).
  You have the option of writing your own converter or providing {tilt-uri}[Tilt]-supported templates to customize the generated output or to convert the AsciiDoc to alternative formats.
  
  NOTE: Asciidoctor is a drop-in replacement for the original AsciiDoc Python processor.
  The project has {tests-uri}[> 1,500 tests] to ensure compatibility with the AsciiDoc syntax.
  
  In addition to the standard AsciiDoc syntax, Asciidoctor recognizes additional markup and formatting options, such as font-based icons (e.g., [x-]`icon:fire[]`) and UI elements (e.g., [x-]`button:[Save]`).
  Asciidoctor also offers a modern, responsive theme based on {foundation-uri}[Foundation] to style the HTML5 output.
  
  == Requirements
  
  