《明史·志·卷十一》
逐次加上弦策，就得到各弦望及次朔，如果满半岁周去掉，就进入缩历，满半岁周又去掉，就又恢复为盈历。
累加弦策，各得弦望及次朔，如满半岁周去之交缩，满半周又去之即复交盈。
Add the string policy sequentially to get the string, the wish and the next begin. If it is removed after a full half-year cycle, it will enter the abridged calendar. When it is removed after a full half-year cycle, it will be restored to the waxing calendar.
<s>[INST] Kindly elucidate the central themes in this passage in English: 累加弦策，各得弦望及次朔，如满半岁周去之交缩，满半周又去之即复交盈。 [/INST] Add the string policy sequentially to get the string, the wish and the next begin. If it is removed after a full half-year cycle, it will enter the abridged calendar. When it is removed after a full half-year cycle, it will be restored to the waxing calendar.</s>
Kindly elucidate the central themes in this passage in English: 累加弦策，各得弦望及次朔，如满半岁周去之交缩，满半周又去之即复交盈。
user
Add the string policy sequentially to get the string, the wish and the next begin. If it is removed after a full half-year cycle, it will enter the abridged calendar. When it is removed after a full half-year cycle, it will be restored to the waxing calendar.
assistant