 
       hello = :world
 
-  Now, let's rollback to the first shell:
+  Now, let's roll back to the first shell:
 
       User switch command
        --> c 1


  ## The User Switch command

  Besides the break command, one can type Ctrl+G to get the to
  the user switch command. When reached, you can type `h` to
  get more information.

  In this switch, developers are able to create new shell and
  alternate in between them. Let's give it a try:

      User switch command

  end

  # Locates and loads an .iex file from one of predefined locations
  defp load_dot_iex(config) do
    path = Enum.find [".iex", "~/.iex"], File.regular?(&1)
    if nil?(path) do
