@MISC{POLYVIE1.MIZ,
  AUTHOR = {Korni{\l}owicz, Artur and P\k{a}k, Karol},
  TITLE = {Vieta's Formula about the Sum of Roots of Polynomials},
  DAY = {25},
  MONTH = {May},
  YEAR = {2017},
  ADDRESS1 = {Institute of Informatics\\University of Bia{\l}ystok\\Cio{\l}kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  ADDRESS2 = {Institute of Informatics\\University of Bia{\l}ystok\\Cio{\l}kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  SUMMARY = {In the article we formalized in the Mizar system
  \cite{Mizar-State-2015} the Vieta formula about the sum of
  roots of a~polynomial $a_n x^n + a_{n-1} x^{n-1} + \cdots + a_1 x + a_0$
  defined over an~algebraically closed field.
  The formula says that
  $x_1 + x_2 + \cdots + x_{n-1} + x_n = -\frac{a_{n-1}}{a_n}$.
  In the article the sum is denoted by \texttt{SumRoots}.},}
