Equation Icon  n u = ∑ Aj(t,x,u) ∂-u + F (t,x,u), x ∈ Σ, t ∈ [0,T], (5.1 ) t j=1 ∂xj u(0,x) = f(x), x ∈ Σ, (5.2 ) b(t,x,u)u = g(t,x ), x ∈ ∂Σ, t ∈ [0,T ], (5.3 )