Sharḥ Mukhtaṣar fī ma`rifat al-taqāwīm (a commentary, presumably on Ṭūsī’s “Mukhtaṣar fī `ilm al-tanjīm wa-ma`rifat al-taqwīm” which is the Arabic version of his Persian “Sī faṣl dar ma`rifat-i taqīm” completed in 658/1260)