Left panel: verification of Eq. (5)for the (S_5/3,Y) structural pair for n = 16,ℓ = 0 mode kernel , where is the right-hand side of this Equation and ℛ is the residual. All quantities are presented in their non-dimensional form. Right panel: verification of Eq. (6)for the (S_5/3,Y) structural pair for modes of degree ℓ = 0,1,2,3 and various radial orders. The models used are the same as in Fig. 2.