“…Note that G.x/ represents the quasi-steady-state of the boundary layer † F -subsystem, (19), when " 1 D 0, that is, 0 D g.x, y,´/ ! y D G.x/, and H.x, G.x// represents the quasi-steady-state of the boundary layer † U -subsystem, (17), when evolving on the manifold of the † F -subsystem.…”