π ^  ( w , a ) = N 1  ( w a )  ∑ b ∈ A   N 1  ( w b )       ∀ ( w , a ) ∈ A m  × A           ( 3 )   MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBamrtHrhAL1wy0L2yHvtyaeHbnfgDOvwBHrxAJfwnaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaWaaeGaeaaakeaafaqabeqacaaabaacciGaf8hWdaNbaKaacqGGOaakcqWG3bWDcqGGSaalcqWGHbqycqGGPaqkcqGH9aqpdaWcaaqaaGqabiab+5eaonaaBaaaleaacqaIXaqmaeqaaOGaeiikaGIaem4DaCNaemyyaeMaeiykaKcabaWaaabeaeaacqGFobGtdaWgaaWcbaGaeGymaedabeaakiabcIcaOiabdEha3jabdkgaIjabcMcaPaWcbaGaemOyaiMaeyicI4mcdaGae0haXheabeqdcqGHris5aaaaaOqaaiabgcGiIiabcIcaOiabdEha3jabcYcaSiabdggaHjabcMcaPiabgIGiolab9bq8bnaaCaaaleqabaGaemyBa0gaaOGaey41aqRae0haXheaaiaaxMaacaWLjaGaeiikaGIaeG4mamJaeiykaKcaaa@6555@