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P. 58

V. The Waring Problem
                        52
                           The full estimate, then, by the inductive hypothesis is
                                          N              1     N 2+o(1)     1
                                 2              1+o(1) −                1−
                              |S|           dN       d  2 k−2  ≤       b  2 k−2   1
                                          b                       b
                                      d|b                                      d|b
                                                 1  o(1)
                                             b
                                    N   2+o(1) −  2 k−2  b  .
                        So we obtain
                                                               1
                                                      1+o(1) −
                                               S   N       b  2 k−1  ,
                        and the induction is complete.
                           Now we continue as follows:


                        Lemma 3. Let k> 1 be a fixed integer. There exists a C 1 such that,
                        for any positive integers N, a, b with (a, b)   1,

                                         N

                                                a             1+o(1) −2 1−k
                                            e     n  k    ≤ C 1 N  b     .
                                                b
                                         n 1
                           Our endpoint will be the following:


                        Theorem. If, for each positive integer s, we write


                                               r s (n)          1,
                                                         k   k
                                                        n +···+n  n
                                                         1   s
                                                          n i ≥0
                        then there exists g and C such that r g (n) ≤ Cè  g/k−1  for all n> 0.



                           The previously cited notions of Schnirelmann allow deducing, the
                        full Waring result from this theorem:
                           There exists a G for which r G (n) > 0 for all n> 0.

                           To prove our theorem, since

                                                                 s
                                                1
                                                             k
                                     r s (n)            eàxm ) eà −nx)dx,
                                               0  m≤n 1/k
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