∇ A = [ ∂ A  ∂ w 1    ∂ A  ∂ w 2    ∂ A  ∂ w 3    .... ∂ A  ∂ w 3 l      ]   T        ( 7 )    MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=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@5671@