It refers to the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation, which the term al-jabr (algebra) originally referred to.[29] Algorithm: Coming from al-Khwarizmi's Latin name 'algoritmi'. al-Khwarizmi is sometimes called the 'Grand Father' of computers, because without algorithms, there wouldn't be any computers.[6][30] Automatic controls: The Banu Musa's preoccupation with automatic controls distinguishes them from their Greek predecessors, including the Banu Musa's "use of self-operating valves, timing devices, delay systems and other concepts of great ingenuity."[31] Chess manual: The oldest known chess manual was in Arabic and dates to 840–850, written by Al-Adli ar-Rumi (800–870), a renowned Arab chess player, titled Kitab ash-shatranj (Book of Chess).