Lot Essay
This important treatise by Al-Kashi was composed in 1427 AD and dedicated to Ulugh Beg's library. In the prologue of the manual, Al-Kashi gives a list of some of his works. The treatise deals with arithmetics and subjects such as Tartaglia's or Pascal's triangle, the demonstration of the proof by 9, the absolute sexagesimal system and decimal fractions. It also deals with trigonometry and algebra. Al-Kashi died in Samarqand in 1429 (art. 'al-Kashi', in Brill, 1986-2000, vol.IV, pp.702-703).