Organic Act of the Control Yuan Committees Article 7

Committee meetings shall be attended by a majority of the committee members, excluding members on field inspection or investigation assignments. Meeting resolutions must be approved by a majority of the members present.
中文原文 監察院各委員會組織法第7條
委員會之開會,須有各該委員會委員除外出調查視察者外之過半數出席。
其決議須經出席委員過半數之通過。

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