  Basic ideas of muon tracker technique for the solution of primary cosmic ray
(PCR) composition problem in the energy range $10^{17}-10^{18}$ eV are
presented. The approach uses MC simulation data made with CORSIKA6.990 for
"Pamir-XXI" site conditions. Similar technology can certainly be developed for
other observation levels and interaction models. One can probably extend it to
much higher primary energies.
