On concerning of the Fedorenko finite superelements method and projectional methods

In this paper we consider some results in the theoretical analysis of the Fedorenko Finite Superelements Method (FSEM). We introduce the variational equation which natural finite-dimensional approximation leads to the FSEM. For construction of the variational equation Poincare-Steklov operators were used. Using pointed variational equation one can construct whole class of its approximations with suitable projectional methods.