  A continuous infinite system of point particles interacting via two-body
strong superstable potential is considered in the framework of classical
statistical mechanics. We define some kind of approximation of main quantities,
which describe macroscopical and microscopical characteristics of systems, such
as grand partition function and correlation functions. The pressure of an
approximated system converge to the pressure of the initial system if the
parameter of approximation $a\to 0$ for any values of an inverse temperature
$\beta >0$ and a chemical activity $z$. The same result is true for the family
of correlation functions in the region of small z
