  The situation of the metastable phase decay on the several types of
heterogeneous centers is considered. The method to spread the monodisperse
approximation on the situation of the strong unsymmetry is presented. The
simple analytical formulas for the main characteristics of the nucleation are
given. Three approximations for the supersaturation behavior are suggested and
the results of their application are analysed. This section is devoted to the
derivation of the general formulas.
