anchor.diff:  
   [<Extension;Sealed>]
   type Item2 =
  -    static member inline       Item2 (t :'a          ) = (^a : (member Item2: _ ) t)
       [<Extension>]static member Item2 ((_, b, _, _, _)) = b
       [<Extension>]static member Item2 ((_, b, _, _)   ) = b
       [<Extension>]static member Item2 ((_, b, _)      ) = b
  
positive.code: 
  [<Extension;Sealed>]
  type Item5 =
      static member inline       Item5 (t :'a          ) = (^a : (member Item5: _ ) t)
      [<Extension>]static member Item5 ((_, _, _, _, e)) = e
  
      static member inline Invoke value = 
  
negative.code: 
  [<Extension;Sealed>]
  type Item1 =
      [<Extension>]static member Item1 ((a, _, _, _, _)) = a
      [<Extension>]static member Item1 ((a, _, _, _)   ) = a
      [<Extension>]static member Item1 ((a, _, _)      ) = a
  