Π δ  ( v , w ) = ∑ x ∈ A δ    p ( v x w )         ( 47 )   MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBamrtHrhAL1wy0L2yHvtyaeHbnfgDOvwBHrxAJfwnaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaWaaeGaeaaakeaacqqHGoaudaWgaaWcbaacciGae8hTdqgabeaakiabcIcaOiabdAha2jabcYcaSiabdEha3jabcMcaPiabg2da9maaqafabaGaemiCaaNaeiikaGIaemODayNaemiEaGNaem4DaCNaeiykaKcaleaacqWG4baEcqGHiiIZimaacqGFaeFqdaahaaadbeqaaiab=r7aKbaaaSqab0GaeyyeIuoakiaaxMaacaWLjaGaeiikaGIaeGinaqJaeG4naCJaeiykaKcaaa@556F@