let P(n) be a property indexed by N. we shall say that P(n) holds for large x if there is an N1 > n such that P(n) is true for all n>N1. Hence by definition, xn converges to a if and only if xn-2 is small for large n. What we mean by this is that given any prescribed positive quantity x , we can choose N1 large enough so that xn-1 is less than E for all n>N1