anchor.diff:  
           let mutable comparer = None
   
  +        let mutable disposeCnt = 0
  +
           let getComparer (f : seq<AdaptiveGLVMFragment>) =
               match comparer with
                   | Some cmp -> cmp
  
positive.code:             }
  
          override x.Dispose() =
              last.Dispose()
              fragmentReader.Dispose()
  
      and SortedInterpreterProgram(parent : CameraSortedSubTask, objects : aset<PreparedMultiRenderObject>, createComparer : Ag.Scope -> IMod<IComparer<PreparedMultiRenderObject>>) =
          inherit AbstractRenderProgram()
  
negative.code:                     current <- f
  
                  if not <| isNull current then current.Next <- last
                  else first <- last
              )
  
          override x.Run() =
              
              if disposeCnt > 0 then
                  failwithf "Running disposed glvmprogram"
  
              vmStats.TotalInstructions <- 0
              vmStats.RemovedInstructions <- 0
  