Be more precise

Author: PeterJCLaw

simulator/programming/time.md

@@ -18,7 +18,7 @@ implementing precise movements in your robot
   busy doing something without giving the simulator a chance to run.
 
   This usually indicates that you have a loop somewhere which is expecting time
-  to advance on its own and which should be modified to call <code>sleep</code>
+  to advance on its own and which should be modified to call <code>R.sleep</code>
   occasionally (even a very small value will allow the simulator to progress).
 </div>