Li Rui (Chinese: 李锐; pinyin: Lǐ Ruì; 8 December 1768 in Suzhou – 30 June 1817 in Suzhou) was a Chinese mathematician. Li discovered independently an equivalent version of what is known today as Descartes' rule of signs.
References Joseph Warren Dauben and Christoph J. Scriba, eds., Writing the history of mathematics: its historical development, Birkhäuser, 2002, p. 303. O'Connor, John J.; Robertson, Edmund F., "Li Rui (mathematician)", MacTutor History of Mathematics Archive, University of St Andrews