In an exactly analogous way we get for vectors E 2 and H 1 the following expression: ∫ ∫ V ( H 1 ⋅ ⋅ j ω ω μ μ H 2 + E 2 ⋅ ⋅ j ω ω ϵ ϵ E 1 + E 2 ⋅ ⋅ J 1 ) d ⁡ ⁡ V = − − ∮ ∮ S ( E 2 × × H 1 ) ⋅ ⋅ d S ^ ^ .