anchor.diff:      | Help, _ ->
           Console.WriteLine(helpText)
           main state
  +
       | Error(msg), _ -> 
           Console.Error.WriteLine(msg)
           main state
   
  +    | Quit, _ -> 
  +        exit 0
  +      
     // Run the application!
     do main(State())
  
positive.code:     | Parse of bool
      | Error of string
      | Help
  
    /// Parse 'help' command
    let help = string "help" |> Parser.map (fun _ -> Help)
  
    /// Parse 'declarations' command
    let declarations = string "declarations" |> Parser.map (fun _ -> Declarations)
  
negative.code:     ==================
      help               
        - display this help message
      quit
        - quit the program
      errors
        - get error messagaes reported by last parse
      declarations
  