G.Villar's Method^[4] is improved to prove theorems for the existence of periodic solution(limit cycles of Liènard equation and a more general class of
The phenomena of dark caves had been studied long ago.However it is scarely on the probabilistic features of dark caves of digits.In this paper the probabilisti
In this paper,the distance-sability of nonlinear discrete system is investigated by means of the Gauss-Seidel iteration method.Some algebric criteria of the dis