ABSTRACT
The justification of mathematical models can be realized by the passage to the limit. One can analyze the convergence of the sequences using the Cauchy criterion, if it is applicable. This chapter considers the integer p-adic numbers. Then physicists determine general p-adic numbers using the technique of definition of rational numbers on the basis of integers. It is possible to realize the standard arithmetic operations on the p-adic numbers. The representation of the p-adic numbers as a series with a finite set of negative indexes is an analogue of the representation of the function by the Laurent series. The existence of the sequence that converges with respect to first metric and diverges with respect to the second one and the sequence with inverse properties prove non-equivalence of the usual and p-adic metric.
