AHVĀZĪ, a 4th/10th century mathematician. He was a contemporary of Abū Jaʿfar Ḵāzen (fl. ca. 950-970), whom he mentions. There is no convincing reason to accept his identification by Suter and Sezgin with Abu’l-Ḥosayn Aḥmad b. Ḥosayn Ahvāzī Kāteb who is mentioned by Bīrūnī (Āṯār al-bāqīa, pp. 289, 293; Chronology, pp. 284, 288-89) as an expert on the ecclesiastical hierarchy and the ceremony of christening in Constantinople. He is the author of Šarḥ al-maqālat al-ʿāšera men ketāb Oqlīdes (“Commentary on the tenth book of Euclid”) in eight sections, which is preserved in a number of manuscripts. One of these also contains a Resāla fi’l-mīzān (“Epistle on the balance”) attributed to him.