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Unit 12: General Convergence Theorems




          then h  (x)   h(x) and h (x)   f (x)                                                  Notes
               n            n     n
                 h  is bounded by the boundedness of h and vanishes outside E  as
                  n
                 x   E – E    h(x) = 0   h (x) = 0 because f (x)   0.
                                     n             n
                 Since h  = h or h  = f
                       n      n   n
                 h  is measurable function on E
                  n
                 If h = h, then h    h
                    n        n
                 If h = f  < h < f
                    n   n
                 then f    h as f    f
                      n      n
                 h    h
                  n
                 Thus h    h
                       n
                 Since h (x)    h(x) for each x   E  and {h } is a sequence of measurable function on E
                       n                         n
                 By Bounded Convergence Theorem


                                      h   h    h   h  lim h
                                                      n    n
                                     E   E   E E  E      E
                 as E = (E – E )   E  & (E – E )   E  =

                                       =  lim h  n
                                         n
                                            E

                                       =  lim f
                                              n
                                         n
                                            E
                                         lim f as E  E
                                              n
                                         n
                                            E
                                     h   lim f n
                                         n
                                    E       E
          Taking supremum over all h   f, we get

                                sup h    lim f n
                                 h f     n                                        … (1)
                                   E        E

                                     f   lim f n
                                         n
                                    E       E
          Since {f } is monotonically increasing sequence and f     f
                n                                   n
                                     f   f
                                      n
                                    f     f
                                     n

                                lim f     f                                       … (2)
                                n    n




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