Abu'l Hasan ibn Ali al Qalasadi (1412-1486) was an Arab mathematician known for being one of the most influential voice in algebraic notation since antiquity. He wrotes numerous books on arithmetic and algebra, including al-Tabsira fi'lm al-hisab (Arabic , التبصير ÙÙŠ علم Ø§Ù„ØØ³Ø§Ø¨)(Clarification of the science of arithmetic).