Equation Icon  ˙0 3--0 ψ1 + ∂Ψ = ∂ σ , (5.1 ) Ψ˙ = 0, (5.2 ) -- Ψ = Ψ, -- (5.3 ) Ψ ≡ ψ02 + ∂2 σ0. (5.4 )