Decay on several sorts of heterogeneous centers: Special monodisperse   approximation in the situation of strong unsymmetry. 1. General results
  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. 
V.Kurasov (Saint-Petersburg State University)