[Authors]
 M. I. Grigoriev, V. N. Malozemov, A. N. Sergeev

[Title]
  The main lemma of the polar forms theory

[AMS Subj-class]
 41A10 Approximation by polynomials

[Abstract]
 In terms of polar forms, a criterion of equality of values of two
 algebraic polynomials of order $n$ on two variables together with
 their partial derivatives of order up to $q$, in a given point,
 is obtained.

[Comments]
 Russian, 6 pp.

[Contact e-mail]
 m_grigoriev@list.ru
 malv@math.spbu.ru
 aser57@mail.ru