mputed by solving the 11 congruence equations, it would be a very large number. Upon examining the values of N for all the almanacs that used a superior epoch, it is found that with two exceptions all of them were less than 100 million years, which were too small if they were really the solution of the 11 equations. How, then, did the almanac makers computed the superior epoch?</p><p>Unfortunately, the ancient computation method was gradually forgotten after the abolishment of the <i>sh&#224;ngyu&#225;n</i>