False position method Moroccan origin. Leonardo of Pisa (Fibonacci) devoted Chapter 13 of his book "Liber Abaci" (AD 1202) to explaining and demonstrating the uses of double false position, terming the method "regulis elchatayn" after the "al-khaṭāʾayn" method that he had learned from Arab sources. In 1494, Pacioli used the term "el cataym" in his book "Summa de arithmetica", probably taking the term from Fibonacci. Other European writers would follow Pacioli and sometimes provided a translation into Latin or the vernacular. For instance, Tartaglia translates the latinized version of Pacioli's term into the vernacular "false positions" in 1556. Pacioli's term nearly disappeared in
Midfielder Midfielder A midfielder is an association football position. Midfielders are generally positioned on the field between their team's defenders and forwards. Some midfielders play a disciplined defensive role, breaking up attacks, and are otherwise known as defensive midfielders. Others blur the boundaries, being more mobile and efficient in passing: they are commonly referred to as deep-lying midfielders, play-makers, box-to-box, or holding midfielders. The number of midfielders on a team and their assigned roles depends on the team's formation; the collective group of these players on the field is sometimes referred to as the midfield. Most managers assign at least one