The three college law ("sanshefa"), also called the Three Hall system, regulated the education of future officials in the Taixue (National University). It divided the Taixue into three colleges. Students first attended the Outer College, then the Inner College, and finally the Superior College. One of the aims of the three-colleges was to provide a more balanced education for students and to de-emphasize Confucian learning. Students were taught in only one of the Confucian classics, depending on the college, as well as arithmetics and medicine. Students of the Outer College who passed a public and institutional examination were allowed to enter the Inner College. At the Inner College there were two exams over a two year period on which the students were graded. Those who achieved the superior grade on both exams were directly appointed to office equal to that of a metropolitan exam graduate. Those who achieved an excellent grade on one exam but slightly worse on the other could still be considered for promotion, and having a good grade in one exam but mediocre in another still awarded merit equal to that of a provincial exam graduate.