1988 Criminal Commutation Act Article 9

Punishments for multiple offenses that have final judgment for commutation and with execution terms yet to be determined shall be commuted respectively pursuant to the provisions of Article 2, and Article 4 to Article 7 of this Act, then apply Article 51 of the Criminal Code for the appropriate execution terms.Punishments for multiple offenses that have final judgment for commutation and have execution terms determined shall be re-determined for appropriate execution terms in accordance with the preceding paragraph. The remainder of the punishments for offenses that deserve commutation, as stipulated in Article 54 of the Criminal Code shall be determined in the same way.
中文原文 中華民國七十七年罪犯減刑條例第9條
裁判確定前犯數罪均應減刑而未定執行刑者,就各罪依第二條、第四條至第七條規定減刑後,適用刑法第五十一條定其應執行之刑。
裁判確定前犯數罪均應減刑而已定執行刑者,仍依前項規定另定應執行之刑;刑法第五十四條之餘罪,均應減刑者亦同。

English translation for reference only; the Chinese text prevails. Not legal advice.