anchor.diff:              let world = snd <| World.removeGroup SceneAddress scene world
               (Cascade, world)
   
  -        static let determineEnemyTurn field (enemy : Entity) rand =
  +        static let determineEnemyTurn precedingTurns field (enemy : Entity) rand =
               match enemy.ControlType with
               | Player ->
                   debug <| "Invalid ControlType '" + acstring enemy.ControlType + "' for enemy"
  
positive.code:                 let (player, enemies, rand) =
                      match playerTurn with
                      | NavigationTurn navigationDescriptor ->
                      
                          // get enemy turns
                          let (enemyTurns, rand) = determineEnemyTurns field enemies rand
  
                          // ->
                          // -> any intermediate processing of turns goes here
  
negative.code:                 (enemyTurn, rand)
              | Uncontrolled -> (NoTurn, rand)
  
          static let determineEnemyTurns playerTurn field enemies rand =
              List.foldBack
                  (fun (enemy : Entity) (enemyTurns, rand) ->
                      let (enemyTurn, rand) = determineEnemyTurn (playerTurn :: enemyTurns) field enemy rand
                      (enemyTurn :: enemyTurns, rand))
                  enemies
                  ([], rand)
  