anchor.diff:  //                // TODO
   //                generate streamCallHistory activeEvents remainingStreams
               | _ as eop -> 
  +                let streamCallHistory = strmIdToProcess :: streamCallHistory
                   ExeOp(strmIdToProcess, eop) :: generate streamCallHistory activeEvents remainingStreams
           else
               // streams are all empty
  
positive.code: 
              // book keeping
              let execOp = List.head strmToProcess       
              let streamCallHistory = strmIdToProcess :: streamCallHistory
              let remainingStreams = streams |> List.map (fun strm -> 
                  if strm = strmToProcess then List.tail strm
                  else strm)
  
negative.code:                         | None -> 9999
                      let syncPenalty = 
                          match strm with
                          | EmitEvent _::_ -> 1000
                          | WaitOnEvent _::_ -> -1000
                          | _ -> 0
                      callsBetween + syncPenalty) 
  