anchor.diff:                  (List.ofSeq enemies)
                   []
   
  -        static let determineEnemyNavigationActivities enemyAddresses world =
  -            let enemies = World.getEntities enemyAddresses world
  +        static let determineEnemyNavigationActivities enemies world =
               List.foldBack
                   (fun (enemy : Entity) enemyActivities ->
                       let noCurrentEnemyActionActivity =
  
positive.code:             let world =
                  match optNewPlayerActivity with
                  | Some newPlayerActivity ->
                      let playerAddress = getPlayerAddress address
                      runCharacterActivity newPlayerActivity playerAddress address world
                  | None -> world
  
              // determine (and set) enemy desired turns if applicable
  
negative.code:                 match optNewPlayerActivity with
                  | Some (Action _)
                  | Some (Navigation _) ->
                      let rand = Rand.make <| gameplay.GetOngoingRandState world
                      let player = proxyPlayer gameplay
                      let enemies = proxyEnemies gameplay world
                      let (enemyDesiredTurns, rand) = determineDesiredEnemyTurns occupationMap player enemies rand world
                      let enemies = Seq.map2 (fun (enemy : Entity) turn -> enemy.SetDesiredTurn turn) enemies enemyDesiredTurns
                      gameplay.SetOngoingRandState (Rand.getState rand) world
                  | Some NoActivity
                  | None -> world
  
              // run enemy activities in accordance with the player's current activity
              let world =
                  let player = proxyPlayer gameplay
                  let enemies = proxyEnemies gameplay world
                  match player.GetActivityState world with
                  | Action _ -> world
                  | Navigation _ 
                  | NoActivity ->
                      let newEnemyActionActivities = determineEnemyActionActivities enemies world
                      let newEnemyNavigationActivities = determineEnemyNavigationActivities enemies world
                      if List.exists ActivityState.isActing newEnemyActionActivities then
                          let world = runEnemyActivities newEnemyActionActivities newEnemyNavigationActivities enemies gameplay world
                          cancelNavigation player world
                      else runEnemyNavigationActivities newEnemyNavigationActivities enemies gameplay world
  
              // teh world
              world
  