Or perhaps we attach a third field to the tuple and call it a "priority" and require that everything with higher priority is done before anything with low prior

Or perhaps we attach a third field to the tuple and call it a "priority" and require that everything with higher priority is done before anything with low priority. Let's call it (I am probably inventing the term here) "priority queue". Author actually writes about it. There are plenty of tasks that may be of low value to him but are absolutely essential for external reasons.