anchor.diff:                      else (enemies, rand)
                   | None -> (enemies, rand)
   
  -            // update enemy activities
  -            let enemies = updateEnemyActivities player enemies
  +            // update enemy activities in accordance with the player's current activity
  +            let enemies =
  +                match player.ActivityState with
  +                | Action _ -> enemies
  +                | Navigation _ -> updateEnemyNaviagationActivities enemies
  +                | NoActivity -> updateEnemyActivities enemies
   
               // advance player activity
               let player = CharacterActivity.advanceActivity player
  
positive.code:                 Entity.setDesiredTurn NoTurn enemy
              else enemy
  
          static let updateEnemyActivities (player : Entity) enemies =
  
              // determine enemy activities
              let newEnemyActionActivities = determineEnemyActionActivities enemies 
              let newEnemyNavigationActivities = determineEnemyNavigationActivities enemies
  
              // update enemy activities
              match player.ActivityState with
              | Action _ -> enemies
              | Navigation _ ->
                  let anyEnemyNavigationActivity =
                      List.exists
                          (function Navigation _ -> true | Action _ | NoActivity -> false)
                          newEnemyNavigationActivities
                  if anyEnemyNavigationActivity
                  then List.map2 tryUpdateEnemyActivity newEnemyNavigationActivities enemies
                  else enemies
              | NoActivity ->
                  let anyEnemyActionActivity =
                      List.exists
                          (function Action _ -> true | Navigation _ | NoActivity -> false)
                          newEnemyActionActivities
                  let newEnemyActivities = if anyEnemyActionActivity then newEnemyActionActivities else newEnemyNavigationActivities
                  List.map2 tryUpdateEnemyActivity newEnemyActivities enemies
  
          static let advanceCharacters gameplayAddress playerTurn world =
  
  
negative.code:                             match enemy.DesiredTurn with
                              | ActionTurn _ -> NoActivity
                              | NavigationTurn navigationDescriptor -> Navigation navigationDescriptor
                              | CancelTurn -> NoActivity
                              | NoTurn -> NoActivity
                          else NoActivity
                      enemyActivity :: enemyActivities)
  