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248    5. Concepts of Stochastic Convergence

                                    The proof in this case is similar to the one in the previous case and hence
                                 it is left out as the Exercise 5.2.6.
                                    Case 4: u ≠ 0, v ≠ 0
                                    From (5.2.9), using similar arguments as before, we observe that















                                 In the last step in (5.2.10), the first and third terms certainly converge to zero
                                 since          ,         ≠  0 as n → ∞. For the middle term in the last step
                                 of (5.2.10), let us again use the triangular inequality and proceed as follows:




                                 which implies that P{| U  | > 2 | u |} → 0 as n → ∞, since    as n
                                                      n
                                 → ∞. Hence the lhs in (5.2.10), converges to zero as n → ∞. This completes
                                 the proof of part (ii). "
                                    (iii) In view of part (ii), we simply proceed to prove that    as n
                                 → ∞. Note that | V  – v | ≥ | v | – | V  | which implies that
                                                 n              n




                                 Observe that the lhs of (5.2.11) converges to unity as n → ∞ because
                                 as n → ∞. This implies



                                 Let us denote W  = | V  – v | {| V  ||  v |} . Then, for any arbitrary but
                                                                       –1
                                                                n
                                                      n
                                                n
                                 otherwise fixed ε(> 0), we can write
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