“…],[1]) can be factored as G =G • ∂ whereG is the standard Green's operator of the boundary problem (∂ 3 , [E 0 ∂, E 1 ∂, 1 0 ]). HenceG = G • x 0 and, assuming (6) for the composition, also (∂ 3 , [E 0 ∂, E 1 ∂, ], [0]) = (∂, [E 0 ], [0]) • (∂ 2 , [E 0 ∂, E 1 ∂, ], [1]),…”