anchor.diff:          this.Simplexes.Remove simplexName
   
   /// An ECS system that stores zero to many of the same component per entity id.
  -type SystemMultiplexed<'c, 'w when 'c : struct and 'c :> 'c Component> (buffered, isolated, ecs : 'w Ecs) =
  -    inherit SystemCorrelated<'c ComponentMultiplexed, 'w> (buffered, isolated, ecs)
  -
  -    new (ecs) = SystemMultiplexed (false, false, ecs)
  +type SystemMultiplexed<'c, 'w when 'c : struct and 'c :> 'c Component> (buffered, ecs : 'w Ecs) =
  +    inherit SystemCorrelated<'c ComponentMultiplexed, 'w> (buffered, ecs)
  +
  +    new (ecs) = SystemMultiplexed (false, ecs)
   
       member this.QualifyMultiplexed simplexName entityId =
           if this.QualifyCorrelated entityId then
  
positive.code:             correlationsBack.Add (index, entityId)
              correlateds.Array.[index] <- comp
  
              // register correlation with ecs if needed
              if not isolated then
                  match ecs.Correlations.TryGetValue entityId with
                  | (true, correlation) ->
                      correlation.Add this.Name |> ignore<bool>
                      ecs.CorrelationChanges.[entityId] <- correlation
                  | (false, _) ->
                      ecs.Correlations.Add (entityId, HashSet.singleton StringComparer.Ordinal this.Name)
                      ecs.CorrelationChanges.[entityId] <- ecs.EmptyCorrelation
  
              // make component ref
              ComponentRef.make index correlateds correlatedsBuffered
  
negative.code:             | (false, _) -> false
  
          // unregister correlation from ecs if needed
          if unregistered then
              match ecs.Correlations.TryGetValue entityId with
              | (true, correlation) ->
                  correlation.Remove this.Name |> ignore<bool>
  