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
Christopher Sullivan (soccer) Christopher Sullivan (soccer) Christopher Sullivan (born April 18, 1965 in San Jose, California) is a retired U.S. soccer midfielder/forward and current soccer trainer and sports broadcaster. Sullivan began playing soccer at a young age. When he was four he began playing with West Valley S.C. He attended and played soccer at NCAA Division II powerhouse University of Tampa. He was inducted into the University of Tampa Athletic Hall of Fame in October 2010. While playing for the University of Tampa, he earned a second team Division II All American in 1986 and a first team All American in 1987. His