Al-Hawārī's commentary on Ibn al-Bannā's \textit{Talkhīs}: contents and influences (Q2878032)

The \textit{Talkhīṣ a`māl al-ḥisāb} (\textit{Condensed book on the operations of arithmetic}, ca.\ 1300) by Ibn al-Bannā was one of the most popular textbooks on arithmetic in the western Islamic world. A first commentary on the work, supplying further explanations of techniques and numerical examples, was by the author himself. At least 10 further commentaries, some of which in prose, were written after Ibn al-Bannā's death in 1321, but that by his student al-Hawarī\ is the only one written during Ibn al-Bannā's lifetime. This article relates what is known about al-Hawarī's life and the date of his commentary. It describes the five manuscripts of the commentary that were consulted by the authors and compares the contents of the commentary with the \textit{Talkhīṣ} itself. It presents an overview of symbols and notations, discusses several techniques, among which the ``method of scales'' (double false position), and outlines the influence of al-Hawarī's commentary, which was still in use in Tunesia during the 19th century.