Du risalah az ?Izz al-Din-i Zanjani

Not much is known about ?Izz al-Din Zanjani's (d. 660/1262) personal life other than that at different times in his career he was in Mosul, Baghdad, Bukhara and Tabriz, where Nasir al-Din Tusi (d. 672/1274) wrote his Tadhkira fi 'l-hay?a at his request. To posterity Zanjani is maybe best known for his work on Arabic morphology, the Mabadi? al-tasrif, also known as Tasrif al-Zanjani and al-?Izzi, on which many commentaries and supercommentaries were written. Zanjani has four more works on linguistics, besides one work on astronomy and six treatises on mathematics, two of which are published in facsimile here. The first of these is his ?Umdat al-hisab on arithmetic and the second the Qistas al-mu?adala on equations. Following Zanjani's own statements at the beginning of these treatises they were written for practical reasons, people in general standing in need of a good text on arithmetic, while the text on equations was especially relevant for jurists.