Figure shows a system for batch processing. The system operations can be described as follows: $(1)$ A weighed quantity of dry material is added to liquid that has filled the tank to level L$1,(2)$ The mixture is stirred, and heat is applied to maintain the temperature between TL and TH for a period of $10$ minutes. $(3)$ With the stir and heater off, the batch is emptied down to level L$2.$ The whole process then starts again. Prepare a flowchart that describes the sequence of events. Be sure to consider any events that could pcocur in parallel.