False position method ibn Luqa (10th century), an Arab mathematician from Baalbek, Lebanon. He justified the technique by a formal, Euclidean-style geometric proof. Within the tradition of medieval Muslim mathematics, double false position was known as "hisāb al-khaṭāʾayn" ("reckoning by two errors"). It was used for centuries to solve practical problems such as commercial and juridical questions (estate partitions according to rules of Quranic inheritance), as well as purely recreational problems. The algorithm was often memorized with the aid of mnemonics, such as a verse attributed to Ibn al-Yasamin and balance-scale diagrams explained by al-Hassar and Ibn al-Banna, all three being mathematicians of
Captain of the guard the leading guard for correctional institutes, regarding jails and prisons. Captain of the guard The Captain of the Guard is a position for a military force. It is also a position for jail and prison terms. A Captain of the Guard is the commanding position of a military security force. The position of Captain of the Guard is not or no longer associated with the rank of Captain. The Guard is commonly associated with bodyguard duty for royalty or head of state, but the Guard can refer to the military security force of a city or region such as a