Equation Icon  ∑n j ∂- ut = A ∂xju + F0(t,x), x ∈ Σ, t ≥ 0, (5.6 ) j=1 u (0, x) = f(x), x ∈ Σ, (5.7 ) bu = g(t,x), x ∈ ∂Σ, t ≥ 0, (5.8 )