anchor.diff:  
       // Next, add a handler for this new event.
       eventForDelegateType.Publish.AddHandler(
  -        EventHandler(fun _ _ -> printfn "this is handler was added with Publish.AddHandler"))
  +        EventHandler(fun _ _ -> printfn "this handler was added with Publish.AddHandler"))
   
       // Next, trigger this event (note that sender argument should be set).
       eventForDelegateType.Trigger(null, EventArgs.Empty)
  
positive.code: 
      // When mutating a value, use '<-' to assign a new value.
      //
      // Note that '=' is not the same as this.  '=' is used to test equality.
      otherNumber <- otherNumber + 1
  
      printfn "'otherNumber' changed to be %d" otherNumber
  
negative.code:     let tuple2 = (1, "fred", 3.1415)
  
      printfn "tuple1: %A\ttuple2: %A" tuple1 tuple2
      
      /// A simple tuple of integers with a type annotation.
      /// Type annotations for tuples use the * symbol to separate elements
      let tuple3: int * int = (5, 9)
  
      /// Tuples are normally objects, but they can also be represented as structs.
      ///
  