∂ P ( N )  ∂ N 0  ( w )   = − A 0  ( w )  N 0  ( w )   × P ( N )       ( 17  )    MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaWcaaqaaiabgkGi2kabdcfaqjabcIcaOGqabiab=5eaojabcMcaPaqaaiabgkGi2kab=5eaonaaBaaaleaaieaacqGFWaamaeqaaOGaeiikaGIaem4DaCNaeiykaKcaaiabg2da9iabgkHiTmaalaaabaGaemyqae0aaSbaaSqaaiabicdaWaqabaGccqGGOaakcqWG3bWDcqGGPaqkaeaacqWFobGtdaWgaaWcbaGae4hmaadabeaakiabcIcaOiabdEha3jabcMcaPaaacqGHxdaTcqWGqbaucqGGOaakcqWFobGtcqGGPaqkcaWLjaGaaCzcamaabmaabaGaeGymaeJaeG4naCdacaGLOaGaayzkaaaaaa@5086@