Abū al-Ḥasan ibn ʿAlī al-Qalaṣādī

Abu'l-Hasan Ali ibn Muhammad al-Qalasadi was a Muslim Arab mathematician from Al-Andalus specializing in Islamic inheritance jurisprudence. Franz Woepcke stated that al-Qalaṣādī was known as one of the most influential voices in algebraic notation for taking "the first steps toward the introduction of algebraic symbolism''. He wrote numerous books on arithmetic and algebra, including al-Tabsira fi'lm al-hisab.