sidebar
Equation Icon  [(η1′ + η3;2′) + (η1 + η2′;3);22′] = [D2 ′D2D3D3 ′ − I]ϕ1 , (57 ) [(η1 + η2′;3) + (η1′ + η3;2′);3′3] = [D3D3 ′D2 ′D2 − I]ϕ1 . (58 )