anchor.diff:              Address.hash this.GroupAddress
   
           interface Simulant with
  -            member this.SimulantAddress = atoa<Group, Simulant> this.GroupAddress
  +            member this.SimulantAddress = simulantAddress
               end
   
           interface Group IComparable with
  
positive.code:         // check that address is of correct length for a game
          do if Address.length gameAddress <> 0 then failwith "Game address must be length of 0."
  
          /// Create a game reference.
          new () = Game (Address.empty)
  
  
negative.code:             Address.hash this.GameAddress
  
          interface Simulant with
              member this.SimulantAddress = simulantAddress
              end
  
          interface Game IComparable with
  