β −  ( x , a , b ) = β ( a , b ) − β ( x , a , b )         ( 72  )     = ∫ x 1  t a − 1      ( 1 − t )  b − 1   d t   ( 73  )        MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeGabaabfuaabmqaciaaaeaaiiGacqWFYoGydaahaaWcbeqaaiabgkHiTaaakiabcIcaOiabdIha4jabcYcaSiabdggaHjabcYcaSiabdkgaIjabcMcaPiabg2da9iab=j7aIjabcIcaOiabdggaHjabcYcaSiabdkgaIjabcMcaPiabgkHiTiab=j7aIjabcIcaOiabdIha4jabcYcaSiabdggaHjabcYcaSiabdkgaIjabcMcaPiaaxMaacaWLjaaabaWaaeWaaeaacqaI3aWncqaIYaGmaiaawIcacaGLPaaaaeaacqGH9aqpdaWdXaqaaiabdsha0naaCaaaleqabaGaemyyaeMaeyOeI0IaeGymaedaaaqaaiabdIha4bqaaiabigdaXaqdcqGHRiI8aOGaeiikaGIaeGymaeJaeyOeI0IaemiDaqNaeiykaKYaaWbaaSqabeaacqWGIbGycqGHsislcqaIXaqmaaGccqWGKbazcqWG0baDaeaadaqadaqaaiabiEda3iabiodaZaGaayjkaiaawMcaaaaaaaa@66A5@