《旧唐书·本纪·卷九》
十一月，毁东都明堂之上层，改拆下层为乾元殿。
冬十月，毁东都明堂之上层，改拆下层为乾元殿。
In November, the upper level of Mingtang in Dongdu City was destroyed and the lower level was demolished and rebuilt into the Qianyuan Palace.
<s>[INST] Identify the key themes in this Classical Chinese text and explain them in English: 冬十月，毁东都明堂之上层，改拆下层为乾元殿。 [/INST] In November, the upper level of Mingtang in Dongdu City was destroyed and the lower level was demolished and rebuilt into the Qianyuan Palace.</s>
Identify the key themes in this Classical Chinese text and explain them in English: 冬十月，毁东都明堂之上层，改拆下层为乾元殿。
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In November, the upper level of Mingtang in Dongdu City was destroyed and the lower level was demolished and rebuilt into the Qianyuan Palace.
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