Statute of Open Prisons Article 16

With regard to those inmates whose terms of imprisonment are mitigated, their progressive treatment or the terms of parole shall be calculated according to the terms of imprisonment after the mitigation.If the parole referred to in the preceding paragraph is revoked. The mitigated terms of imprisonment shall be recovered.
中文原文 外役監條例第16條
受刑人經縮短應執行之刑期者,其累進處遇或假釋之刑期,應以其縮短後之刑期計算之。
前項假釋經撤銷者,回復其縮短前之刑期。

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