% issue query start. to begin the sleeps/timers

start :- % get the current time 
         get_time(StartTime), 
         % sleep 3 seconds then display the elapsed time in milliseconds
         sleep(3), get_time(Time1), Elapsed1 is Time1 - StartTime, write(Elapsed1), nl,
         % sleep 0.5 seconds then display the elapsed time in milliseconds
         sleep(0.5), get_time(Time2), Elapsed2 is Time2 - StartTime, write(Elapsed2), nl.

start.